NMT 04102
ANATOMY AND PHYSIOLOGY NTA Level 4 Facilitator’s Guide for Basic Certificate in Nursing
September 2013
United Republic of Tanzania Ministry of Health and Social Welfare
Ministry of Health and Social Welfare Department of Human Resources Development Nursing Training Section © Ministry of Health and Social Welfare 2013
Table of content Acronyms
iii
Goals and Objectives of the Training Manual .........................................................................vii Overall Goal for training manual ......................................................................................................vii Objectives for training manual..........................................................................................................vii
Introduction viii Module Overview ............................................................................................................................viii Who is the Module For? ..................................................................................................................viii How is the Module Organized? .......................................................................................................viii How Should the Module be Used? ..................................................................................................viii
Session 1:
Introduction to Anatomy and Physiology of the Human Body ...........................1
Session 2:
Human Body Cell Structure and Function.........................................................13
Session 3:
Human Body Tissue and Membrane Structure and Function............................23
Session 4:
Various Parts of the Body Structure ..................................................................41
Session 5:
Anatomical and Physiological Function of the Upper Respiratory System ......57
Session 6:
Function of the Lower Respiratory System .......................................................73
Session 7:
Structure and Physiological Function of the Urinary System............................89
Session 8:
Structure and Function of the Integumentary System......................................107
Session 9:
Structure and Function of Female Reproductive System ................................123
Session 10: Structure and Function of the Female Breast and the Menstrual Cycle ..........137 Session 11: Structure and Functions of the Male Reproductive System.............................145 Session 12: Structure and Function of the Mouth, Oesophagus and Stomach....................153 Session 13: Structure and Function of the Small and Large Intestines...............................169 Session 14: Structure and Function of the Accessory Organs of the Digestive System .....179 Session 15: Digestion and Metabolism of Food in the Body..............................................188 Session 16: Structure and Functions of the Lymphatic System ..........................................195 Session 17: Structure and Functions of the Blood ..............................................................203 Session 18: Structure and Functions of the Blood Vessels and the Heart...........................217 Session 19: Structure and Functions of a Myelinated Neuron ............................................235 Session 20: Structure and Functions of the Central Nervous System .................................241 Session 21: Structure and Functions of the Peripheral and Autonomic Nervous System...253 Session 22: Structure and Functions of the Endocrine System ...........................................269 Session 23: Structure and Functions Musclar System ........................................................285 Session 24: Structure and Functions of the Skeletal System and Joints .............................295 NMT 04102 Anatomy and Physiology
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Session 25: Structure and Functions of the Eye ..................................................................309 Session 26: Structure and Functions of the Ear...................................................................319
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Acronyms DNA RNA FSH PMS CCK GIT HCL ATP BMR ACTH HCO3 Na+ ClO2 CO2 ADP CNS CSF TSH
Deoxyribonucleic Acid Ribonucleic Acid Follicle Stimulating Hormone Premenstrual Syndrome Cholecystokinin Gastro intestinal Tract Hydrochloric Acid ( Adenosine Triphosphate Basal Metabolic Rate Adrenocorticotropic Hormone Bicarbonate Sodium Cloride ion oxygen gas Carbon Dioxide Adenosine Triphosphate Central Nervous System Cerebrospinal Fluid Thyroid stimulating hormone
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Acknowledgement The development of the training manuals for Certificate and Diploma in Nursing (NTA Level 4 to 6) has been possible and accomplished through involvement of different stakeholders. The Ministry of Health and Social Welfare (MoHSW) through the Director of Human Resources Development sends sincere gratitude to the stakeholders including the coordinating team (Department of Nursing and Midwifery Training), TNI, through AIHA and the WINONA state University for funding the activity. The MOHSW would like to thank all those involved during the process for their valuable contribution to the development of these training materials. The ministry of Health would like to thank the Assistant Director for Nursing Training section Mr. Ndementria Vermand, and Ms. Vumilia B.E Mmari (Coordinator for Nursing and Midwifery Training) who tirelessly led this important process. Sincere gratitude is expressed to main facilitator: Mr. Golden Masika, Tutorial Assistant University of Dodoma for his tireless efforts and Mr. Nicolaus Ndenzako Programme consultant of AMCA inter consultant in guiding participants through the process. Special thanks go to the team of contributors representing the Health Training Institutions, hospitals and Universities. Their participation in meetings and workshops and their inputs in the development of the content for each module have been invaluable. It is the commitment of these participants that has made this product possible. These participants are listed with our gratitude below: SN 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. 22. 23. 24.
Name Mary S. Matembo Elialilia M. Herman Alice Chifunda Lilian Wilfreda Aselina Milinga Veronica Mahela Samwel Mwangoka Hamza S. Matagira Elikana Wallace Anna Sangito Pallangyo David Abincha Leon S. Mgohamwende Crescent D. Ombay Kizito B. Tamba Robert E. Moshi Oresta Ngahi Aloyce Ambokile Helma A. Shimbo Elizabeth G. Chezue Hinju Januarius Manase Nsunza Ezekiel Amata Sostenes D. Ntambuto Anna Sangito Pallanyo
Title Nurse Tutor Nurse Tutor Nurse Tutor Nurse Tutor Nurse Tutor Nurse Tutor Nurse Tutor Nurse Tutor Nurse Tutor Nurse Tutor Nurse Tutor Nurse Tutor Nurse Tutor Nurse Tutor Nurse Tutor Nurse Tutor Nurse Tutor Nurse Tutor PNO N Tutor Obstetrian Principal HLT IMC Facilitator HLT Tutor N/Tutor
NMT 04102 Anatomy and Physiology
Institution Korogwe NTC MT. Meru Hospital Mbulu NTC KCMC KCMC Kahama Mbeya SOTM Kahama NTC Kolandoto S/Nursing Kahama NTC Bukumbi NTC Tosamaganga NTC Haydom S/Nursing Ndanda S/N IMTU college of Nursing Muhimbili S/N Kondoa District Hosp. Mwambani NTC MOHSW HIS & QAS Dodoma Regional Hosp. Singida HLTC Mpwapwa Hosp. SMLS MUHIMBILI Kahama SN NTA Level 4, Semester 1
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25. 26. 27. 28. 29. 30. 31. 32. 33. 34. 35. 36. 37. 38. 39. 40. 41. 42. 43. 44. 45. 46. 47. 48. 49. 50. 51. 52. 53.
Naomi Kagya Aloyce Amboikile Golden Masika Vumilia B.E. Mmari Upendo kilume Fatuma Iddi Shango Nasania George Laisser Anande Mungure Robert Masano Ambokile Nolasca Mtega Asteria Ndomba Alfreda Ndunguru Elizabeth Chezua Magwaza Charles Ellen Mwandemele Robert Mushi Anna Mangula Cesilia Mallya Helma Shimba Kapaya Andrew Ntambuto Sostenese Joseph Nkungu Anastazia Dinho Eliaremisa Ayo Grace Mallya Dr. Tecla Kohi Dr. Lilian Msele
Supporting staff: Daniel Muslim Fatuma Mohamed Mbaruku A. Luga Roselinda Rugemalira Veronica Semhando George Laizer Silvanus Ilomo Violet Mrema Walter Ndesanjo
NT Nurse Lecturer CD-NT Nurse Librarian Nurse C/Analyst Nurse Tutor Nurse Tutor Nurse Tutor Senior Lecturer
Muhimbili Kondoa UDOM MOHSW PHN MOHSW Newala MOHSW Mbulu NTC Nkinga NTC Dodoma General Hospital Tukuyu School of Nursing CUHAS MOHSW
Nurse Tutor Nurse tutor
IMTU Mirembe NTC Newala NTC TNMC
Nurse Tutor Paediatrician Senior Lecturer Lecturer
MOHSW RCHS/GBV/VAC-MOHSW MUHAS MUHAS
Driver, Ministry of Health and Social Welfare Health Librarian, Ministry of Health and Social Welfare Driver, Morogoro School of Public Health Nursing Adm. Secretary, Tanzania Nursing & Midwifery Council Secretary Ministry of Health & Social Welfare System Analyst Ministry of Health & Social Welfare System Analyst Ministry of Health & Social Welfare Adm. Secretary, Ministry of Health and Social Welfare System Analyst, Ministry of Health and Social Welfare
Dr. Gozbert Mutahyabarwa Ag: Director of Human Resource and Development,
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Background In 2007 the Ministry of Health and Social welfare (MOHSW) started the process of reviewing the nursing curricula at Certificate and diploma level. In 2008 refined and developed NTA Level 4 to 6 Nursing Curricula and in the same year 2008 started the implementation. The intention was to comply with the National Council for Technical award (NACTE) Qualification framework which offers a climbing ladder for higher skills opportunity. Advanced Diploma awards are not among the awards of the council and do not conform to NACTE framework. Therefore, institutions offering Advanced Diploma in nursing are required to either offer Ordinary Diploma (NTA Level 6) or develop its capacity to offer Bachelor’s Degree (NTA Level 7&8). These programs have been developed in line with the above consideration aiming at providing a room for Nurses to continue to a higher learning and achieve advanced skills which will enable them to perform duties competently. In addition, WHO advocates for skilled and motivated health workers in producing good health services and increase performance of health systems (WHO World Health Report, 2006). Moreover, Primary Health Care Development Program (PHCDP) (2007-15) needs the nation to strengthen and expand health services at ALL levels. This can only be achieved when the Nation has adequate, appropriately trained and competent work force who can be deployed in the health facilities to facilitate the provisions of quality health care services. In line with these new curricula, the MOHSW supported tutors by developing quality standardized training materials to accompany the implementation of the developed curricula. These training materials will address the foreseen discrepancies in the implementation of the new curricula. NTA level 8 training materials have been developed after Curricula validation and verification. This training material has been developed through writers’ workshop (WW) model. The model included a series of workshops in which tutors and content experts developed training materials, guided by facilitators with expertise in instructional design and curriculum development. The goals of Writer’s Workshop were to develop high-quality, standardized teaching materials and to build the capacity of tutors to develop these materials. This product is a result of a lengthy collaborative process, with significant input from key stakeholders (NACTE, MOHSW, AIHA and WINONA University) and experts of different organizations and institutions. The new training package for NTA Level 4-6 includes a Facilitator Guide and Student Manual. There are 28 modules with approximately 520 content sessions
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Rationale The vision and mission of the National Health Policy in Tanzania focuses on establishing a health system that is responsive to the needs of the people, and leads to improved health status for all. Skilled and motivated health workers are crucially important for producing good health through increasing the performance of health systems (WHO, 2006). With limited resources (human and non-human resources), the MOHSW supported tutors by developing standardized training materials to accompany the implementation of the developed CBET curricula. These training manuals address the foreseen discrepancies in the implementation of the new curricula. Therefore, this training manual for Certificate and Diploma program in Nursing (NTA Levels 4-6) aims at providing a room for Nurses to continue achieving skills which will enable them to perform competently. These manuals will establish conducive and sustainable training environment that will allow students and graduates to perform efficiently at their relevant levels. Moreover, this will enable them to aspire for attainment of higher knowledge, skills and attitudes in promoting excellence in nursing practice. Goals and Objectives of the Training Manual Overall Goal for training manual The overall goal of these training manual is to provide high quality, standardized and competence-based training materials for Diploma in nursing (NTA level 4 to 6) program. Objectives for training manual To provide high quality, standardized and competence-based training materials. To provide a guide for tutors to deliver high quality training materials. Enable students to learn more effectively.
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Introduction Module Overview This module content has been prepared as a guide for tutors of NTA Level 4 for training students. The session contents are based on the sub-enabling outcomes of the curriculum of NTA Level 4 Basic Certificate in Nursing. The module sub-enabling outcome as follows: 2.1.1 Comprehend basic anatomy and physiology of human body 2.1.2 Identify various parts of the human body structure and functions 2.1.3 Describe the basic anatomical and physiological functions of human body system Who is the Module For? This module is intended for use primarily by tutors of NTA Level 4 diploma in nursing schools. The module’ sessions give guidance on the time and activities of the session and provide information on how to teach the session to students. The sessions include different activities which focus on increasing students’ knowledge, skills and attitudes. How is the Module Organized? The module is divided into 26 sessions; each session is divided into sections. The following are the sections of each session: Session Title: The name of the session. Learning Tasks – Statements which indicate what the student is expected to learn at the end of the session. Session Content – All the session contents are divided into steps. Each step has a heading and an estimated time to teach that step. Also, this section includes instructions for the tutor and activities with their instructions to be done during teaching of the contents. Key Points – Each session has a step which concludes the session contents near the end of a session. This step summarizes the main points and ideas from the session. Evaluation – The last section of the session consists of short questions based on the learning objectives to check the understanding of students. Handouts are additional information which can be used in the classroom while teaching or later for students’ further learning. Handouts are used to provide extra information related to the session topic that cannot fit into the session time. Handouts can be used by the participants to study material on their own and to reference after the session. Sometimes, a handout will have questions or an exercise for the participants. The answers to the questions are in the Facilitator Guide Handout, and not in the Student Manual Handout. How Should the Module be Used? Students are expected to use the module in the classroom and clinical settings and during self-study. The contents of the modules are the basis for learning Anatomy and Phyiology. Students are therefore advised to learn each session and the relevant handouts and worksheets during class hours, clinical hours and self-study time. Tutors are there to provide guidance and to respond to all difficulty encountered by students.
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Session 1:
Introduction to Anatomy and Physiology of the Human Body
Total Session Time: 120 Minutes Prerequisites None Learning Tasks By the end of this session, students are expected to be able to: Define common terms used in anatomy and physiology Identify the organization of the body as a whole Explain different human body systems Resources Needed Flipcharts, Marker pens, and masking tape White/black board and chalk/whiteboard markers Overhead projector Computer and LCD Anatomical charts Anatomical models Handout 1.1: Terms of Relationship and Comparisons Handout 1.2: Human Body Structural Level Of Organization Handout 1.3: Structure Organization of Human Body from Smallest Level to Largest Level SESSION OVERVIEW Step
Time
Activity/Method
1
05 Minutes
Presentation
Presentation of Session Title and Learning Tasks
2
15 Minutes
Presentation,
Definition of Terms
3
45 Minutes
Presentation
Organization of the Body
4
45 Minutes
Presentation Group Discussion
5
05 Minutes
Presentation
Key Points
6
05 Minutes
Presentation
Evaluation
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Content
Human Body Systems
Session 1 Introduction to Anatomy and Physiology of the Human Body
SESSION CONTENT Step 1: Presentation of Session Title and Learning Tasks (5 minutes) READ or ASK students to read the learning tasks and clarify ASK students if they have any questions before proceeding
Step 2: Common Terms in Anatomy and Physiology (10 minutes)
The common terms used in anatomy and physiology are as follows o Anatomy - Is the study of the structure of the body Is the study of the structure and shape of the body and body parts and their relationship to one another o Physiology - Is the study of functions of the body systems Is study of the physical and chemical processes that take place in living organisms during the performance of life functions It is concerned with such basic activities as reproduction, growth, metabolism, excitation, and contraction as they are carried out within the fine structure, the cells, tissues, organs, and organ systems of the body. Is the study of how the body and its parts work or function o Medial: Toward or at the midline of the body o Lateral: Away from the midline of the body o Proximal: Close to the origin of the body part or the point of attachment of a limb to the body trunk o Distal: Further away from the origin of a body part or the point of attachment of a limb to the body trunk o Superficial: Toward or at the body surface o Deep: Away from the body surface; more internal o Axial: Makes up the main axis of the body. Consists of the head, neck, and trunk o Appendicular: Consists of the appendages or limbs o Superior (cranial or cephalad): Toward the head end or upper part of a structure of the body o Inferior (caudal). Away from the head end or toward the lower part of a structure or the body Refer students to Handout 1.1: Terms of Relationship and Comparisons
Step 3: Organization of the Body (40 minutes) Level 1 - Chemical Level When it comes to the human body, it doesn't get any smaller than the chemical level. This is the level reserved for the building blocks of human life, including atoms and molecules, which combine to make organelles, which determine cell function. These functions can include cell membranes, mitochondria and ribosomes. For the body to function well there must be equilibrium between internal and external environment known as homeostasis NMT 04102 Anatomy and Physiology NTA Level 4, Semester 1
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Session 1 Introduction to Anatomy and Physiology of the Human Body
Homeostasis literally this term means unchanging, but in practice it describes a dynamic, never changing situation kept within narrow limits. When this balance is threatened or lost, there is a serious risk to the well-being of the individual. Some of the factors which must be maintained within a narrow limits are:o Temperature o Water and electrolyte concentrations. o Ph (acidity or alkalinity of body fluids) o Blood glucose level o Blood and tissue oxygen and carbon dioxide levels o Blood pressure Homeostasis is maintained by control systems which detect and responds to changes in the internal environment. Basic components of control mechanism A control system has three basic components o Detectors o Control center o Effectors The control center determines the limits within which the variable factors should be maintained. It receives an input from the detector or sensor and integrates the incoming information. When the incoming signal indicate that an adjustment is needed the control centre responds and its output to the effectors is changed. Mechanism in control system includes:o Negative feedback mechanism o Positive feedback mechanism Negative feedback mechanism o The effectors response decrease or negates the effect of the original stimulus, restoring homeostasis (thus the term negative feedback) Control of the body temperature o When body temperature falls below the present level, this is detected by specialized temperature sensitive nerve endings. o They transmit this information as an input to groups of cells in the hypothalamus of the brain which forms the control center. o The output from the control centre activates mechanisms that raise body temperature (effectors) o These include: Stimulation of skeletal muscles causing shivering Narrowing of the blood vessels in the skin reducing the blood flow to, and heat loss from the peripheries Behavioral changes e.g. we put on more clothes or curl up o When body temperature rises to within the normal range, the temperature sensitive nerve endings no longer stimulates the cells of the control centre and therefore the output of this centre to the effectors ceases. o Most of the homeostatic controls in the body use negative feedback mechanisms to prevent sudden and serious changes in the internal environment. Positive feedback mechanism. o There are only a few of these amplifier or cascade systems in the body.
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Session 1 Introduction to Anatomy and Physiology of the Human Body
o In positive feedback mechanisms, stimulus progressively increases the response, so that as long as stimulus is continued the response is progressively being amplified. Example uterine contractions during labour. Homeostasis imbalance. o This arises when the fine control of factors in the internal environment is in adequate and the level of the factor falls outside the normal range. o If control cannot achieve homeostasis, an abnormal state develops that may threaten health or even life.
Level 2 - Cells Are the basic units of structure and function in living things May serve a specific function within the organism Examples- blood cells, nerve cells, bone cells, etc. Level 3 - Tissues Made up of cells that are similar in structure and function and which work together to perform a specific activity Examples - blood, nervous, bone, etc. Humans have 4 basic tissues: connective, epithelial, muscle, and nerve. Level 4 - Organs Made up of tissues that work together to perform a specific activity Examples - heart, brain, skin, etc. Level 5 - Organ Systems Groups of two or more tissues that work together to perform a specific function for the organism. Examples - circulatory system, nervous system, skeletal system, etc. The Human body has 11 organ systems - circulatory, digestive, endocrine, excretory (urinary), immune (lymphatic), integumentary, muscular, nervous, reproductive, respiratory, and skeletal. Level 6 - Organisms Entire living things that can carry out all basic life processes. Meaning they can take in materials, release energy from food, release wastes, grow, respond to the environment, and reproduce. Usually made up of organ systems, but an organism may be made up of only one cell such as bacteria or protist. Examples - bacteria, amoeba, mushroom, sunflower, human
Refer student to: Handout 1.2: Human Body Structural Level of Organization Handout 1.3: Structure Organization of Human Body From Smallest Level to Largest Level
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Session 1 Introduction to Anatomy and Physiology of the Human Body
Step 4: Human Body Systems (45 minutes) Activity: Small Group Discussion ( 20 minutes) DIVIDE students into small manageable groups ASK students to discussion in groups on eleven body systems for 5 minutes ASK students to provide their response after discussion CLARIFY and summaries by using the contents below
The human body is made up of 11 main systems o The cardiovascular system Has one distinct function; that is to pump the blood. The central organ in this system is the heart. o The digestive system Is one of the most complex systems of the body It provides the body’s means of transforming food to energy. o The endocrine system Is the system that controls the body It includes the pituitary, thyroid, adrenal, pineal, and thymus glands Uses hormones to stimulate the metabolic activities of the cells. These hormones are released into the blood stream. o The immune system Is the body’s main defense against all foreign substances Without the immune system, the body would die immediately from foreign bacteria. Billions of which rest on the skin o The excretory system Get rids of body waste products Composed of multiple organs The main organs are the kidneys The kidneys perform the dual task of filtering out wastes and purifying blood. Other organs include the urinary bladder, the ureters, and the urethra. o The integumentary system Commonly known as the skin enwraps the body and serves several purposes. It is composed of the epidermis and the dermis o The muscular system Is the largest system in the body Muscles are located in practically every region of the body. The limbs are almost entirely made up of muscles. Muscles are unique because they can contract. This contraction sets muscles apart from all other tissues. There are three different types of muscle tissue: cardiac, skeletal and smooth. o The respiratory system Supplies the body with oxygen. It comprises of the nose/Mouth, larynx, pharynx, trachea, bronchi, bronchioles and the lungs Air is inhaled and exhaled through the nose or mouth.
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Session 1 Introduction to Anatomy and Physiology of the Human Body
o The skeletal System The human skeleton consists of more than 200 bones bound together by tough and relatively inelastic connective tissues called ligaments There different types of bones i.e. short bones, long bones, flat bones, and irregular bones o Reproductive system Also known as genital system Is a system of organs within an organism which work together for the purpose of reproduction. The major organs of the human reproductive system include the external genitalia (penis and vulva) as well as a number of internal organs including the gamete producing gonads (testicles and ovaries). Is responsible for the survival of the species by reproduction of the same kind. o Nervous system Have two divisions: the central nervous system and the peripheral nervous system. The central nervous system includes the brain and spinal cord. The peripheral nervous system includes all neural tissue outside the central nervous system. It is divided into motor and sensory systems.
Step 5: Key Points (5 minutes)
Anatomy and physiology is the study of body structure and functions There are six levels of body organization, that is: the Chemical, cell, tissue, system, organ and organism The eleven body systems are: - Respiratory, Digestive, Cardiovascular, Muscular, Skeletal, Nervous, Integumentary. Lymphatic, Endocrine, Reproductive, and Urinary system
Step 6: Evaluation (5 minutes)
Define anatomy and physiology Mention the six levels of body organization Outline the eleven (11) body systems
ASK students if they have any comments or need clarification on any points
References
By T.L. Chancellor, (nd). Human body structural levels of organization. Retrieved on 15th November, 2011 Jacob, S. (1995). Anatomy an examination companion. New York: Churchill Livingstone. Microsoft ® Encarta ® (2007). © 1993-2006 Microsoft Corporation. Seeley, R. R., Stephens T. D., & Tate, P. (2003). Anatomy and Physiology. New York: McGraw-Hill Shier A, Butler J. & Lewis R (2004). Hole’s Human Anatomy & Physiology. New York: McGraw-Hill
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Session 1 Introduction to Anatomy and Physiology of the Human Body
Venes, D. (2001). Taber’s Cyclopedic Medical Dictionary. (19th ed). Philadelphia, USA: Davis F.A Company. Watson, R. (2001). Anatomy and Physiology for Nurses (11th ed.). China: Bailliere Tindall. Waugh, A. & Grant A. (2007). Anatomy and Physiology in Health and Illness. (10th ed.). UK: Churchill Livingstone.
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Session 1 Introduction to Anatomy and Physiology of the Human Body
Handout 1.1: Terms of Relationship and Comparison
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Session 1 Introduction to Anatomy and Physiology of the Human Body
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Session 1 Introduction to Anatomy and Physiology of the Human Body
Handout 1.2: Human Body Structural Levels of Organization
The structural levels of organization determine the different levels of development in the human body, specifically during their growth during pregnancy. The human body is organized from the lowest form of development, which is marked by conception, to the highest, which is characterized by the body's completed basic development just before birth.
Chemical Level When it comes to the human body, it doesn't get any smaller than the chemical level. This is the level reserved for the building blocks of human life, including atoms and molecules, which combine to make organelles, which determine cell function. These functions can include cell membranes, mitochondria and ribosomes. Cellular Level The cells of the human body are the functional units of life. When a human life begins, it starts as a single cell and grows as those cells multiply through mitosis, which makes sure the cellular structure established by the single cell is replicated over and over again and that the body gets a full set of 46 chromosomes. The other major function on the cellular level is cellular differentiation, which facilitates the specific functions of cells and genes in the human body. Cellular differentiation is why one person has blond hair and another has red hair. Tissue Level This is when similar types of cells come together to form tissue in the body. There are four distinct types of tissue. Epithelial tissue is the skin that covers the body. Connective tissue includes blood, cartilage and bone. Muscular tissue produces force, causes motion and gives the body definition. Neural tissue allows electrical impulses to travel throughout the human body. Organ Level When tissues of a similar type come together during the body's development, they form organs. Most organs contain all four types of the tissues mentioned earlier. Organs usually form to perform a specific function, which can include everything from blood movement (the heart) to waste management (the liver and kidneys) to reproduction (male and female sex organs). System Level This is the highest level of the levels of structural organization in the human body. All of the previous building blocks come together to form systems that perform specific human functions. These organ systems include the cardiovascular system (blood flow), the gastrointestinal system (body waste) and the skeletal system (human bones). In all, the human body has 11 organ systems.
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Session 1 Introduction to Anatomy and Physiology of the Human Body
Handout 1.3: Structure Organization of Human Body from Smallest to Largest Level
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Session 1 Introduction to Anatomy and Physiology of the Human Body
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Session 1 Introduction to Anatomy and Physiology of the Human Body
Session 2:
Human Body Cell Structure and Function
Total Session Time: 120 Minutes Prerequisites None Learning Tasks By the end of this session, students are expected to be able to: Identify various parts and structure of the human body cell Identify various functions of the human body cell Explain the interaction of human body cell structure and function Resources Needed Flipcharts, Marker pens and masking tape Black/white board and chalk/white board Slide projector/LCD and computer Overhead projector and transparencies Anatomical Charts Handout 2.1: Detail of Endomembrane System Handout 2.2: Structures of a Cell Handout 2.3: Structure of a DNA SESSION OVERVIEW Step
Time
Activity/Method
Content
1
05 Minutes
Presentation
Presentation of the Session and Learning Tasks
2
50 Minutes
3
25 Minutes
4
30 Minutes
Presentation
Interaction Between Human Body Cell Structure
5
05 Minutes
Presentation
Key Points
6
05 Minutes
Presentation
Evaluation
Presentation, Group Discussion Presentation, Brainstorm
Parts and Structure of the Human Body Cell Functions of the Human Body Cell
SESSION CONTENT Step 1: Presentation of Session Title and Related Tasks (5 minutes) READ or ASK students to read the leaning tasks and clarify ASK students if they have any questions before proceeding
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Session 2 Human Body Cell Structure and Function
Step 2: Various Parts and Structure of the Human Body Cell (50 minutes) Activity: Small Group Discussion ( 20 minutes) DIVIDE students into small manageable groups ASK students to discussion in groups on various parts of the body cells for 5 minutes ASK students to provide their response after discussion CLARIFY and summaries by using the contents below
The human body cell is the smallest functional unit of the body The human body develop from a single cell called the zygote which results from the fusion of the ovum (female egg cell) and the spermatozoon (male germ cell) cell multiplication follows and as the fetus grows, cells with different structural and functional specializations develop, all the cell genetic makeup as the zygote. Individual cells are too small to been seen with naked eye. However they can be seen when their lies of tissue are stained in the laboratory and magnified by a microscope Characteristics of the cell o o o o o o o
Reproduction. When cell growth is complete they reproduce. Irritability. The cell can respond to a stimuli Movement. Some cell may move from one place to another Excretion. Waste products of cell metabolism are passed out of the cell through cell membrane. Growth. Cell are able to grow until they are mature Respiration. Every cell requires oxygen and gives out carbondioxide Metabolism. Changes do take place in all living cell e.g. taking in and utilizing nourishment.
Structure of the human body cell
A cell consists of a plasma membrane inside which there are a number of organelles floating in a watery fluid called cytosol Organelles are small structures with high specialized functions many of which are contained within a membrane they include the:-
o o o o o o o o
Nucleus Mitochondria Ribosomes Endoplasmic reticulum Golgi apparatus Lysosomes Microfilaments Microtubules Refer students to Handout 2.1: Details of Endomembrane System
Plasma membrane
o The plasma membrane consists of two layers of phospholipids (fatty substances) with some protein molecule embedded in them. o Those that extend all the way through the membrane may provide channels that allow the passage of for example electrolytes and non lipid – soluble substances. NMT 04102 Anatomy and Physiology NTA Level 4, Semester 1
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Session 2 Human Body Cell Structure and Function
o The phospholipids molecules have a head which is electrically charged and hydrophilic attracting water and a tail which has no charge and is hydrophobic water repelling. o The phospholipids bi-layer is arranged like a sandwich the hydrophilic leads aligned on the outer surfaces of the membrane and the hydrophilic tails forming a central water repelling layer o These differences influence the transfer of substances across the membrane o The membrane protein perform several functions these are: They give the cell its immunological identity They can act as specific receptors for hormones and other chemical messengers. Some are enzymes Some are involved in transport across the membrane
Organelles
o Nucleus Is the largest organelle and is contained with a membrane similar to the plasma membrane but it has tiny pores through which some substances can pass between it and the cytoplasm i.e. the cell contents excluding the nucleus, Every cell in the body has a nucleus with the exception of mature erythrocytes (red blood cells) The nucleus contains the body’s genetic material, which directs the activities of the cell. This is built from D.N.A and proteins called histones coiled together forming a five network of threads called chromatin The functional subunits of chromosomes are called genes. Each cell contain the total complement of genes required to synthesizes all the proteins in the body but most cells synthesis only the defined range of proteins that are appropriate to their own specialized functions. The transfer of information from nuclear DNA to the site where proteins are synthesized in the cytoplasm is the function of ribonucleic acid (RNA). The formation of RNA is controlled by genes in the DNA, i.e. genetic information passes from DNA to RNA promoting protein synthesis. o Mitochondria These are sausage shaped structures in the cytoplasm, sometimes describes as “power house” of the cell. They are involved in aerobic respiration, the processes by which chemical energy is made available in the cell. This is in the form of ATP, which release energy when the cell breaks it down. Synthesis of ATP is most efficient in the final stages of aerobic respiration, a process requiring oxygen. o Ribosomes These are tiny granules composed of RNA and protein. They synthesize proteins from amino acids, using RNA as the template. When present in free units or in small clusters in the cytoplasm, the ribosomes make proteins for use within the cell. Ribosomes are also found on the outer surface of rough endoplasmic reticulum. o Endoplasmic reticulum. Is a series of interconnecting membranous canals in the cytoplasm NMT 04102 Anatomy and Physiology NTA Level 4, Semester 1
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Session 2 Human Body Cell Structure and Function
There are two types. Smooth and Rough. Smooth Endoplasmic reticulum: This synthesizes lipids and steroid hormones, and is also associated with the detoxification of some drugs. Rough Endoplasmic reticulum: These are site of synthesis of proteins that are “exported” from cells, i.e. enzymes and hormones that pass out of their parent cell to be used by other cells in the body.
o Golgi apparatus. Consists of stacks of closely folded flattened membranous sacs. Present in all cells but is larger in those that synthesize and export proteins. The protein move from the endoplasmic reticulum to the Golgi apparatus where they are ‘packaged’ into membrane bound vesicles called secretory granules. The vesicles are stored and, when needed, move to the plasma membrane, through which are proteins are exported. o Lysosomes These are one type of secretory vesicle formed by the Golgi apparatus. They contain a variety of enzymes involved in breaking down fragment of organelles and large molecules, e.g. (RNA, DNA, carbohydrate, proteins) inside the cell into smaller particles that are either recycled, or extruded from the cell as waste material. In white blood cells contain enzymes that digest foreign material such as microbes. o Microfilaments. These are tiny strands of protein that provide structural support and maintain the characteristic shape of the cell. o Microtubules These are contractile protein structures in the cytoplasm involved in the movement of the cell and of organelles within the cell, the movement of cilia (small projection from the free border of some cells) and possibly the organization of proteins in the plasma membrane. Cell division
Is the process through which cell do replicate themselves. There are two types of cell division.
o Mitosis o Meiosis Refer students to Handout 2.2: Structure of a Cell Mitosis
Occurs when a single cell divides itself into daughter cells, having similar characteristics and attributes. Its process passes into four stages which are:o Prophase During this stage the chromatids become visible within the nucleus and the mitotic apparatus appears. This consists of two centrioles separated by mitotic spindle which is formed from microtubules. The centrioles migrate one to each end of the cell and nuclear envelop disappears o Metaphase
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During this phase the chromatids align on the center of the spindle attached by their centromeres
o Anaphase During anaphase the chromatids in each pair of sister chromatid are separated. One chromatid from each then moves towards each pole of the spindle. o Telophase The mitotic apparatus disappears, the chromosomes uncoil and the nuclear envelop reforms. Following Teleophase the cytoplasma and the plasma membrane divide in half forming two identical cells. The organelles of the daughter cells are incomplete at the cell division but they develop as the cell matures during interphase Refer students to Handout 2.3: Structure of DNA Meiosis
This is the process of cell division that occurs in the formation of reproductive cells (gametes – the ova and spermatozoa) In meiosis four daughter cells are formed after two division During meiosis the pairs of chromosomes separate and one from each pair moves to opposite poles of the “parent” cells. When it divides each of the “daughter” cells has only 23 chromosomes called the haploid. This means that when the ovum is fertilized the resultant zygote has the full complete of 46 chromosomes (the diploid number), half from the father and half from the mother. Thus the child has some characteristics inherited from both parents such as color of hair and eyes, height, facial features and some diseases. Determination of sex depend upon one particular pair of chromosomes (the sex chromosomes) In the female both sex chromosomes are called X chromosomes. In the male there is one X chromosome and a slightly smaller Y chromosome. When the ovum is fertilized by an X bearing spermatozoon the child is female and when by a Y bearing spermatozoon the child is male. o Sperm X + Ovum X = child XX = female o Sperm Y + Ovum X = child XY = male.
Step 3: Functions of the Human Body Cell (25 minutes) Activity: Brainstorming (05 minutes)
Ask students to brainstorm on the functions of a cell ALLOW few students to responses and let others provide unmentioned response WRITE their responses on the white/chalk board CLARIFY and summaries by using the information below
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Session 2 Human Body Cell Structure and Function
Functions of the Human Body Cells Basic unit of life The cell is the smallest part to which an organism can be reduced that still retains the characteristics of life Protection and support Produces and secretes various molecules that provide protection and support of the body Movement Movement of the body occurs because of molecules located within specific cells such as muscle cells Communication Produces and receives chemicals and electrical signals that allow them to communicate with one another Cell metabolism and energy release Chemical reaction that occur within cells are referred to collectively as cell metabolism Inheritance Each cell contains a copy of the genetic information of the individual
Step 4: Interaction of Human Body Cell Structure (30 minutes) Transport mechanism through the cell membrane. Movement of substances in the body cells proceeds usually in one of two main ways. o Diffusion This refer to the movement of a chemical substance from an area of high concentration to an area of low concentration Diffusion also occurs across a semi-permeable membrane, such as the plasma membrane in this case only those molecules able to cross the membrane can diffuse through o Osmosis This is the movement of water down its concentration gradient across a semipermeable membrane when equilibrium cannot be achieved by diffusion of solute molecules. This is usually because the solute molecules are two large to pass through the pores in the membrane. The force with which this occurs is called the osmotic pressure Water crosses the membrane down its concentration gradient from the side with the lower solute concentration to the side with the greater solute concentration.
Step 5: Key Points (5 minutes)
Cell is a basic functional unity of the body A cell consists of a plasma membrane inside which there are a number of organelles Organelles are small structures with high specialized functions many of which are contained within a membrane The organelles found in the cell includes: - Nucleus, Mitochondria, Ribosomes, Endoplasmic reticulum, Golgi apparatus, Lysosomes, Microfilaments, and Microtubules. Movement of substances in the body cells proceeds usually in one of two main ways; Diffusion or Osmosis
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Session 2 Human Body Cell Structure and Function
Step 6: Evaluation (5 minutes)
What is a cell? Mention the six characteristics of a cell Explain the movement of substances in and out the cell
ASK students if they have any comments or need clarification on any points
References
Seeley, R. R., Stephens, T. D., Tate, P. (2003). Anatomy and Physiology. New York: McGraw-Hill Shier, A., Butler, J. & Lewis, R. (2004). Hole’s Human Anatomy & Physiology. New York: McGraw-Hill Standring, S. (2008). Grays’s Anatomy: The Anatomical Basis of Clinical Practice. United Kingdom: Churchill Livingstone/Elservier. Thibodeau, G. A. & Patton, K. T. (1999). Anatomy & Physiology. Saint Louis: Mosby, Von Hoffman Press, Inc Waugh, A. & Grant, A. (2006). Ross and Willson Anatomy and physiology in Health and Illness. United Kingdom: Churchill Livingstone/Elservier.
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Session 2 Human Body Cell Structure and Function
Handout 2.1: Detail of Endomembrane System
Source: ladyofhats, (2006)
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Session 2 Human Body Cell Structure and Function
Handout 2.2: Structure of a Cell
Source: Gray’s Anatomy 39 Ed.(2005)
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Session 2 Human Body Cell Structure and Function
Handout 2.3 : Structure of DNA Genetic Material Two different kinds of genetic material exist: deoxyribonucleic acid (DNA) and ribonucleic acid (RNA). Most organisms use DNA for their long-term information storage. Deoxyribonucleic acid (DNA) is a nucleic acid that contains the genetic instructions used in the development and functioning of all known living organisms and some viruses. During processing, DNA is transcribed, or copied into a special RNA, called mRNA. This mRNA is then transported out of the nucleus, where it is translated into a specific protein molecule. The biological information contained in an organism is encoded in its DNA sequence. RNA is also used for information transport (e.g., mRNA) and enzymatic functions (e.g., ribosomal RNA) in organisms that use DNA for the genetic code itself. Transfer RNA (tRNA) molecules are used to add specific amino acids during the process of protein translation. A human cell has genetic material in the nucleus (the nuclear genome) and in the mitochondria (the mitochondrial genome). In humans the nuclear genome is divided into 23 pairs of linear DNA molecules called chromosomes The structure of DNA is made up of three components namely base, sugar and phosphate. o The bases are purine and pyrimidine. o The purine are adenine and guanine while the pyrimidines are cytosine and thymine A fifth pyrimidine base, called uracil (U), usually takes the place of thymine in RNA and differs from thymine by lacking a methyl group on its ring. Uracil is not usually found in DNA These bases are in pair purine pairs with pyrimidine. In DNA molecule guanine is paired with cytosine with three hydrogen bonds while adenine pairs with thymine with two hydrogen bonds This arrangement of two nucleotides binding together across the double helix is called a base pair. As hydrogen bonds are not covalent, they can be broken and rejoined relatively easily. The two strands of DNA in a double helix can therefore be pulled apart like a zipper, either by a mechanical force or high temperature. As a result of this complementarity, all the information in the double-stranded sequence of a DNA helix is duplicated on each strand, which is vital in DNA replication. Indeed, this reversible and specific interaction between complementary base pairs is critical for all the functions of DNA in living organisms.
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Session 3:
Human Body Tissue and Membrane Structure and Function
Total Session Time: 120 Minutes Prerequisites None Learning Tasks By the end of this session, students are expected to be able to: Identify various parts and structure of the human body tissue and membrane Identify various functions of the human body tissue and membrane Explain the interaction of human body tissue, membrane structure and functions Resources Needed Flipcharts, Marker pens, and masking tape Black/white board and chalk /whiteboard markers Slide projector/LCD and computer Overhead projector and transparencies Anatomical charts Handout 3.1 Different Types of Epithelial Tissue Handout 3.2 Different Types of Epithelial Tissue Handout 3.3 Different Types of Glandular Epithelial Tissue Handout 3.4 Different Types of Connective Tissue Handout 3.5 Structure if Cell Membrane Handout 3.6 Structure if Cell Membrane and Cytoskeletal SESSION OVERVIEW Step
Time
Activity/Method
Content
1
05 minutes
Presentation
Presentation of the Session and Learning Tasks
2
65 minutes
3
20 minutes
Presentation, Group Discussion Presentation, Brainstorm
4
20 minutes
Presentation
Parts and Structure of the Human Body Tissue and Membrane Functions of the Human Body Tissue and Membrane Interaction Between Human Body Tissue, Membrane Structure and Functions
5
05 minutes
Presentation
Key Points
6
05 minutes
Presentation
Evaluation
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Session 3 Human Body Tissue and Membrane Structure and Function
SESSION CONTENT Step 1: Presentation of Session Title and Learning Tasks (5 minutes) READ or ASK students to read the learning tasks and clarify ASK students if they have any questions before proceeding
Step 2: Various Parts and Structure of the Human Body Tissues and Membrane (65 minutes) Activity: Small Group Discussion ( 25 minutes) DIVIDE students into small manageable groups ASK students to discussion in groups on various parts of the human body tissues and membrane for 5 minutes ALLOW groups ask students to provide their response for 2 minutes each CLARIFY and summaries by using the contents below
Tissue is a group or collection of similar cells and their intercellular substance that perform a particular function. Tissues are classified according to the size, shape and function of these cells as followsThere are four main types of tissue each of which has subdivisions. These are:o Epithelial tissue or epithelium o Connective tissue o Muscle tissue o Nervous tissue Epithelial tissue o This group of tissue is found covering the body and linking cavities and tubes. The structure of epithelium is closely related to its functions which include:o Protection of underlying structures from e.g. dehydration, chemical and mechanical damage o Secretion o Absorption o Epithelial tissue may classified as follows Simple epithelial tissue: a single layer of cells Stratified epithelial tissue: several layers of cells. Simple epithelium Simple epithelium consists of a single layer of identical cells and is divided into 4 types. It is usually found on absorptive or secretory surfaces, where the single layer enhances these processes and not usually on surfaces subjected to stress. The four types of simple epithelium are:-
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Squamous (pavement epithelium) This is composed of a single layer of flattered cells. The cells fit closely together like flat stones, forming a thin and very smooth membrane. Diffusion takes freely, through this thin and smooth inactive living of the following structures e.g. heart, blood vessels, lymph vessels and alveoli of the lungs where it is also known as endothelium. Cuboidal (cubical) epithelium o This consists of cylindrical shaped cells fitting closely together lying on a basement membrane. o It forms the tubules of the kidneys and is found in some gland. Columnar epithelium o This is formed by a single layer of cells, rectangular in shape, on a basement membrane. o It is found living the organs of the alimentary tract and consist of mixture of cells some absorb the products of the digestion and other secrete mucus. o Mucus is a thick sticky substance secreted by modified columnar cells called goblet cells. Ciliated epithelium o This is formed by columnar cells each of which has many fine, hair like processes called cilia o Ciliated epithelium is found lining the uterine tubes and most of respiratory passages o In the uterine tubes the cilia propel mucus towards the throat Stratified epithelia o Stratified epithelia consist of several layers of cells of various shapes. o The superficial layers grow up from below. o Basement membrane is usually absent. o The main function is to protect underlying structure from mechanical wear and tear. o They are divided into: Stratified Squamous Epithelium This is composed of a number of layers of cells of different shapes representing newly formed and mature cells o Stratified Cuboidal epithelial This is composed of two or more layers of cells and they are found sweat gland ducts, Egg producing vesicles (follicles) of ovaries, Sperm producing ducts (somniferous tubules) of testis. o Non keratinized stratified epithelium This is found on wet surfaces that may be subjected to wear and tear but are protected from the drying e.g. the conjunctiva of the eyes, the lining of the mouth, the pharynx, the esophagus and the vagina. o Keratinized stratified epithelium This is found on dry surface that are subjected to wear and tear e.g. skin, hair and nails o Transitional epithelium This is composed of several layers of pear shaped cells and is found lining in the urinary bladder. It allows for stretching as the bladder fills.
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Session 3 Human Body Tissue and Membrane Structure and Function
Refer students to: o Handout 3.1: Different types of epithelial tissue o Handout 3.2: Different types of epithelial tissue o Handout 3.3: Different Types of Epithelial Tissue
Connective tissue. o Is the most abundant tissue in the body, o The cells forming the connective tissue are more widely separate from each other than that forming the epithelium and intercellular substance is present in considerably larger amounts. o Major functions of connective tissue are Binding and structural support Protection Transport Insulation o Cells of connective tissue involved are Fibroblasts Fat cells Macrophage Leukocytes Mast cells o Types of connective tissue o Loose (areolar) connective tissue This is the most generalized of all connective tissue. It is found in almost every part of the body providing elasticity and tensile strength. It connect and support other tissues e.g. Under the skin Between muscle Supporting blood vessels and nerves. In the alimentary canal In the glands supporting secretory cells o Adipose tissue. It consist of fat cells (adipocytes) containing large fat globules, in a matrix of areola tissue.
Two Types: White and Brown White adipose tissue. o This makes up 20 to 25% of the body weight in well nourished adults. o The amount of adipose tissue in an individual is determined by the balance between energy and expenditure. Brown adipose tissue This is present in the newborn. When brown tissue is metabolized, it produces energy and considerably more heat than other fat, contributing to the maintenance of body temperature. In adults it is presenting only in small amounts. Dense connective tissue o Fibrous tissue this is made up mainly of closely packed bundles of collagen fibers with very little matrix. NMT 04102 Anatomy and Physiology NTA Level 4, Semester 1
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Session 3 Human Body Tissue and Membrane Structure and Function
o Fibrocystic are few in number and are found lying in rows between the bundles of fibers. o Fibrous tissue is found. Forming the ligaments, which bind bones together As an outer protective covering for bone called periosteum As an outer protective covering of some organs e.g. the kidneys, lymph nodes and the brain. Forming muscle sheaths called muscle fascia which extend beyond the muscle to become the tendon that attaches the muscle to bone. o Elastic tissue. It is capable of considerable extension and recoil. It is found in organs where alteration of shapes is required e.g. in large blood vessels walls, the epiglottis and the outer ears. o Blood Is a fluid connective tissue. Lymphoid tissue o This tissue has a semi solid matric with fine branching reticulum fibers. It contain white blood cells (monocytes and lymphocytes). These are found in blood and in lymphoid tissue in the Lymphnode Spleen Palatine and pharyngeal tonsils Vermiform appendix Solitary and aggregated nodes in the small intestine Wall of the large intestine. Cartilage. Cartilage is a much firmer tissue than any of the other connective tissues, the cells are called chondrocytes and are less numerous, there are three types. Hyaline cartilage o This appears as a smooth bluish white tissue, it is found o On the surfaces of the parts of the bone that form joints o Forming the costal cartilages, which attach the ribs to the stem o Forming part of the larynx, trachea and bronchi. Fibrocartilage o This consists of dense masses of white collagen fiber in a matrix similar to that of hyaline cartilage with the cells widely dispersed. o It is a tough, slightly flexible tissue found. As pads between the bodies of the vertebrae, called the intervertebral discs Between the articulating surfaces of the bones of the tense joint called semilunar cartilages. On the rim of the bony sockets of the hip and shoulder joints deepening the cavities without restricting movement. As ligament joining bones. Elastic cartilage o This flexible tissue consists of yellow elastic fibers lying in a solid matrix. It forms the pinna or lobe of the year, the epiglottis and part of the tunica media of blood vessel walls. o Bone Bone is connective tissue with cells (osteocytes) surrounded by a matrix of collagen fiber that is strengthened by inorganic salts, especially calcium and
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Session 3 Human Body Tissue and Membrane Structure and Function
phosphate This provides bones with their characterized strength and rigidity. Two types of bone can be identified by the naked eyes these are Compact bone – solid or dense appearance Cancellous or spongy bone – has fine honey comb appearance
Refer students to Handout 3.4: Different Types of Connective Tissue .
Muscle tissue o There are three types of muscle tissue, which consists of specialized contractile cells, they may be classified as follows Skeletal muscle tissue. This may be described as skeletal striated or voluntary muscle. It is called voluntary because contraction is under conscious control. Smooth muscle tissue This may also be described as non striated or involuntary. It is found in the walls of hollow organs. Regulating the diameter of blood vessels and parts of the respiratory tract. Propelling contents of the ureters ducts of glands and alimentary tract Expelling contents of the urinary bladder and uterus. Cardiac muscle tissue o This type of muscle tissue is found exclusively in the wall of the heart. o It is not under conscious control but when viewed under microscope across stripes characteristics of voluntary muscles can be seen. o Function of muscle tissue Muscle functions by alternate phases of contraction and relaxation When the fibers contract they becomes thicker and shorter Skeletal muscle fibers are stimulated by motor nerve impulses originating in the brain or spinal cord and ending at the neuromuscular junction. Smooth and cardiac muscle have the intrinsic ability to initiate contraction; in addition contraction is stimulated by autonomic nerve impulses, some hormones and local metabolites. Nervous tissues o Two types of tissue are found in the nervous system Excitable cells These are called neurons and they initiate, receive, conduct and transmit information. Non excitable cells These support the neurons
Membranes Membranes are sheets of epithelial tissue and their supporting connective tissue that cover or line internal structures or cavities. The main membranes are o Mucous membrane This is the most lining of the alimentary tract, respiratory tract and genitourinary tracts and is sometimes referred to as the mucosa. o Serous membrane Serous membrane or serosa, secrete serous watery fluid which cover the surface of the membrane. NMT 04102 Anatomy and Physiology NTA Level 4, Semester 1
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Session 3 Human Body Tissue and Membrane Structure and Function
The serous membranes are named according to their location as follows Pleural membrane covering the lungs Pericardial membrane covering the heart Peritoneal membrane covering the peritoneum o Synovial membrane This membrane is found lining the joint cavities and surrounding tendons, which could be injured by rubbing against bones e.g. Over the wrist joint. Refer Students to: o Handout 3.5: Structure if Cell Membrane o Handout 3.6: Structure of Cell Membrane and Cystoskeletal
Step 3: Functions of Tissues and Membranes (20 minutes) Activity: Brainstorming (10 minutes)
Ask students to brainstorm on functions of different types of tissues and membranes ALLOW few students to responses and let others provide unmentioned response WRITE their responses on the white/chalk board CLARIFY and summaries by using the information below
Epithelial tissues o Protect underlying structures o Act as barriers preventing the movement of many substances o Permit the passage of substances e.g. carbon dioxide and oxygen o Secret substances e. g. sweat glands o Absorb substances as some contains carrier molecules Connective tissues o Enclose and separate organs e. g Liver and Kidneys o Connect tissues to one another e. g Tendons, Ligaments o Support and allow movements e. g skeletal system o Storing e.g Adpose tissue stores high energy molecules o Cushioning and insulating e. g the skin helps to conserve heat o Transporting. Blood transports substances throughout the body o Protecting. Immune cells protect the body against toxins and tissue injury Muscle tissues o Attachment o Aid in movement o Relaxation and contraction of the body o Helps in flexion of the body o Cardiac muscles responsible for pumping action of the heart o Regulate the size of organs Nervous tissue
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Session 3 Human Body Tissue and Membrane Structure and Function
o Coordination of various body activities o Control body activities o Conduction of action potential Membranes o Protection o Absorption o Secretions of fluids
Step 4: The Interaction of Human Body Tissue, Membrane Structure and Functions (20 minutes)
Body tissues and membranes have a different mechanism of interacting in the human body as follows: o Simple epithelium is involved with diffusions, secretions or absorption. o Stratified epithelium serves as a protective role. o Squamous cells function in diffusion or filtration o Cuboidal or columnar cells which contain more organelles secrete or absorbs. o A smooth, free surface reduces friction. o Microvilli increase surface area, and cilia move materials over the cell surface o Tight junctions bind adjacent cells together and form a permeability barrier. o Gape junctions allow intercellular communication
Step 5: Key Points (5 minutes)
Tissue is a group or collection of similar cells and their intercellular substance that perform a particular function. Tissues are classified according to the size, shape and function of these cells The main functions of tissues and membranes are protection; absorption; supporting; connection of tissues; transportation; and secretion of substances
Step 6: Evaluation (5 minutes)
Define the term tissue, membrane Mention four types of tissues What are the five main functions of tissue and membranes
ASK students if they have any comments or need clarification on any points
References
Seeley, R. R., Stephens, T. D., & Tate, P. (2003). Anatomy and Physiology. New York: McGraw-Hill Shier, A., Butler, J. & Lewis, R. (2004). Hole’s Human Anatomy & Physiology. New York: McGraw-Hill Standring, S. (2008). Grays’s Anatomy The Anatomical Basis of Clinical Practice. United Kingdom: Churchill Livingstone Elservier. Thibodeau, G. A., Patton. K. T., (1999). Anatomy & Physiology. Saint Louis: Mosby, and Von Hoffman Press Inc
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Session 3 Human Body Tissue and Membrane Structure and Function
Waugh, A. & Grant, A. (2006). Ross and Willson Anatomy and Physiology in Health and Illness. United Kingdom: Churchill Livingstone Elservier.
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Session 3 Human Body Tissue and Membrane Structure and Function
Handout 3.1: Different Types of Epithelial Tissue
Relaxed
stretched
Source: SEER Training Modules
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Session 3 Human Body Tissue and Membrane Structure and Function
Handout 3.2: Different Types of Epithelial Tissue
Source: SEER Training Modules
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Session 3 Human Body Tissue and Membrane Structure and Function
Handout 3.3: Different Types of Glandular Epithelium
Source: Gray’s Anatomy 39
Ed.(2005).
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Session 3 Human Body Tissue and Membrane Structure and Function
Handout 3.4: Different Types of Connective tissue
Dense regular connective tissue in a tendon
Source: Gray’s Anatomy 39
Ed.(2005).
Elastic fibres
Source: Grays Anatomy 2005.
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Session 3 Human Body Tissue and Membrane Structure and Function
Loose connective tissue
Source: Gray’s Anatomy 39
Ed.(2005).
Adipose tissue
Source: Gray’s Anatomy 39
Ed.(2005).
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Session 3 Human Body Tissue and Membrane Structure and Function
Fibrous connective tissue
Source: Gray’s Anatomy 39
Ed.(2005)
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Session 3 Human Body Tissue and Membrane Structure and Function
Handout 3.5 : Structure of Cell Membrane
Source: LadyofHats , "http://en.wikipedia.org/wiki/Eukaryote"2006
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Session 3 Human Body Tissue and Membrane Structure and Function
Handout 3.6: Structure of Cell Membrane and Cytoskeleton
Source: Grays Anatomy 2005.
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Session 3 Human Body Tissue and Membrane Structure and Function
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Session 3 Human Body Tissue and Membrane Structure and Function
Session 4:
Various Parts of the Body Structure
Total Session Time: 120 Minutes Prerequisites None Learning Tasks By the end of this session, students are expected to be able to: Identify various parts of the human body structure Identify various functions of the human body parts Explain the interaction between human body parts structure and functions Resources Needed Flipcharts, Marker pens and Masking tapes Black/white board and Chalk/whiteboard markers Slide projector/LCD and computer Overhead projector and transparencies Anatomical charts Handout 4.1: Anatomical Quadrants Handout 4.2: Abdominal Regions Handout 4.3: Body Planes Handout 4.4: Human Body Cavity Handout 4.5: Thoracic Cavity and its Division Handout 4.6: Surface Anatomy of the Abdomen Handout 4.7: Visceral and Arrangement of the Peritoneum Worksheet 4.1: Abdominal – Pelvic Region SESSION OVERVIEW Step
Time
Activity/Method
1
05 Minutes
Presentation
2
60 Minutes
3
25 Minutes
4
20 Minutes
Presentation
Interaction Between Human Body Structure and Functions
5
05 Minutes
Presentation
Key Points
6
05 Minutes
Presentation
Evaluation
Presentation of the Session and learning Tasks
Presentation, Group Discussion Presentation Brainstorm
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41
Parts and Structure of the Human Body Functions of the Human Body Parts
Session 4 Various Parts of the Body Structure
SESSION CONTENT Step 1: Presentation of Session Title and Learning Tasks (5 minutes) READ or ASK students to read the Learning tasks and clarify ASK students if they have any questions before proceeding
Step 2: Various Parts of The Body Structure (60 minutes) Major Parts of the Human Body Structure Upper limbs o Arms o Forearm o Wrist o Hand Lower limbs o Thigh o Leg o Ankle o Foot Central region o Head o Neck o Trunk (thorax, abdomen and pelvis)
Refer students to Handout 4.1: Abdominal Quadrants Abdominal regions o It is subdivided into four quadrants Right upper quadrant Left upper quadrant Right lower quadrant Left lower quadrant Refer students to Handout 4.2. Abdominal regions Sometimes the abdomen is divided into nine regions o Right hypochondriac region o Epigastric region o Left hypochondriac region o Right lumbar region o Umbilical region o Left Lumbar region o Right iliac region o Hypogastric region o Left iliac region Refer students to Handout 4.3.Body Planes
Human body Planes o Saggital Plane
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Session 4 Various Parts of the Body Structure
Runs vertically through the body and separate it into right and left part o Midsaggital plane Divides the body into equal right and left halves o Transverse or horizontal plane Runs vertically from right and left it divides the body into superior and inferior parts o Frontal or coronal plane Runs vertically from right and left and divides the body into anterior and posterior. Refer students to Handout 4.4: Human Body Cavity Body Cavities The organs that make up the body systems are contained in four cavities:o Cranial cavity It contains the brain and its boundaries are formed by the bones of the skull. Anteriorly – 1 Frontal bones Laterally – 2 Temporal bones Posteriorly – 1 Occipital bone Superiorly – 2 Parietal bones Inferiorly – 1 Sphenoid and 1 ethmoid bone and parts of the frontal, temporal and occipital bones. o Thoracic cavity Situated in the upper part of the trunk. Its boundaries are formed by a bony frame work and supporting muscles. Anteriorly – The sternum and costal cartilages of the ribs Laterally – 12 pairs o ribs and the intercostals muscles Posteriorly – the thoracic vertebrae and the intervertebral disc between the bodies of the vertebrae. Superiorly – the structures forming the root of the neck Inferiorly – the diaphragm a dome – shaped muscle. The mains organs and structures contained in the thoracic cavity are The trachea, 2bronchi, 2 lungs The heart, aorta, superior and inferior venacava, numerous and other blood vessels. The esophagus. Refer students to Handout 4.5: Thoracic Cavity and its Division o Abdominal cavity This is the largest cavity in the body and is oval in shape. It is situated in the main part of the trunk and its boundaries are Superiorly – the diaphragm which separates it from the thoracic cavity. Anteriorly – the muscle forming the anterior abdominal wall Posteriorly – the lumbar vertebrae and muscles forming the posterior abdominal wall Inferiorly – the pelvic cavity with which it is continuous The mains organs and structures contained in the abdominal cavity are Urinary bladder, lower parts of the ureters and the urethra. In the female, the organs of the reproductive system, the uterus, uterine tubes, ovaries and vagina. In the male some of the organs of the reproductive system; the prostate gland, NMT 04102 Anatomy and Physiology NTA Level 4, Semester 1
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Session 4 Various Parts of the Body Structure
seminal vesicles, spermatic cords, deferent ducts (vas deferens ejaculatory ducts and the urethra (common to the reproductive and urinary systems) The stomach, small intestine and most of the large intestine The liver, gall bladder, bile ducts and pancreas The spleen 2 kidneys and the upper part of the ureter 2 adrenal (suprarenal) glands Numerous blood vessels, lymph vessels nerves Lymph nodes
Refer students to Handout 4.6: Surface Anatomy of the Abdomen o Pelvic cavity The pelvic cavity is roughly funnel shaped and extends from the lower end of the abdominal cavity. The boundaries are: Superiorly – it is continuous with the abdominal cavity Anteriorly – the pubic bones Posteriorly – the sacrum coccyx Laterally – the innominate bones Inferiorly – the muscles of the pelvic floor This cavity contains: Sigmoid colon, rectum and anus Some loops of the small intestine Urinary bladder, lower parts of the uterus and the urethra Refer students to Handout 4.7: Visceral and Arrangement of the Peritoneum Activity: Group Discussion (15 minutes) DIVIDE students into small manageable groups Refer students to Worksheet 4.1: Abdominal – Pelvic Region
ASK students to discuss on abdominal – pelvic region for 5 minutes ALLOW one group to responses and let others provide unmentioned response CLARIFY and summaries by using the information below
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Session 4 Various Parts of the Body Structure
Step 3: Various Functions of The Body Parts (25 minutes) Activity: Brainstorming (5 minutes)
Ask students to brainstorm on various part of the body for 2 minutes ALLOW few students to responses and let others provide unmentioned response WRITE their responses on the white/chalk board CLARIFY and summaries by using the information below
Head o o o
Brain o o o
Connects to the trunk, Arms helps to catch, to hold and carry objects, also helps in fine movements Legs helps to walk, jump, and run The legs sustain the entire weight of the body and carry it where it needs to go
Cavities o
Connects all the other parts and hosts many internal organs such as heart, lungs, stomach, liver, kidney and reproductive organs
Limbs o o o o
Connects the head to the trunk Helps the head to move up and down, left and right Protects the nerves that send sensory and motor information’s from the brain to the rest of the body
Trunk o
Is the center of all vital functions of the body. We can survive, think, love, create and remember through the brain Controlling center by receiving, analyzing, directing sensory information to various parts of the body
Neck o o o
Hosts most of the sensory organs (nose, eyes, ears and mouth) Protects the brain It connects to the neck
Holds and protects internal organs
Regions and planes o
Helps in allocating, diagnosing anatomical and structural dysfunction of human body organs
Step 4: Body Parts Interaction (20 minutes)
In respiration the lungs and the brain rely on mutual communication. Involving receptors, nerves and their muscles, their interaction enables breathing that matches the body’s’ fluctuating demands for oxygen The most obvious system that interacts with muscular system is the skeletal system, nervous system and the circulatory system. Muscles are also involved in digestive system, respiratory system and the immune system
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Session 4 Various Parts of the Body Structure
Step 5: Key Points (05 minutes)
The body is made up of the upper limbs; Lower limbs and the Central region The abdominal is subdivided into four quadrants: -Right upper quadrant; Left upper quadrant; Right lower quadrant; and Left lower quadrant There are four main body planes: - Saggital Plane; Midsaggital plane; Transverse or horizontal plane; and Frontal or coronal plane The organs that make up the body systems are contained in four cavities:- Cranial; Thoracic; Abdominal; and Pelvic cavities
Step 6: Evaluation (5 minutes)
Ask student to volunteer to draw and indicate the 9 abdominal regions Mention the body cavities What are the organs contained in the central region of the body? How does the body parts interact each other
ASK students if they have any comments or need clarification on any points
References
http/www.ehow.com/about5476167 body-parts-functions.html. Retrieved on 15th November, 2011 Seeley, R. R., Stephens, T. D. & Tate P. (2005). Anatomy and Physiology. New York: McGraw-Hill Shier, A., Butler, J. & Lewis, R. (2004). Hole’s Human Anatomy & Physiology. New York: McGraw-Hill Standring, S. (2008). Grays’s Anatomy The Anatomical Basis of Clinical Practice. United Kingdom: Churchill Livingstone Elservier. Thibodeau, G. A., Patton, K. T. (1999). Anatomy & Physiology. Saint Louis: Mosby, and Von Hoffman Press, Inc Waugh, A. & Grant, A. (2006). Ross and Willson Anatomy and physiology in Health and illness. United Kingdom: Churchill Livingstone Elservier.
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Handout 4.1: Abdominal Quadrants
Source: Grays Anatomy 2005.
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Session 4 Various Parts of the Body Structure
Handout 4.2: Abdominal Regions
Source: Gray’s Anatomy 39
Ed.(2005)
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Handout 4.3: Body Planes
Source: Gray’s Anatomy 39
Ed.(2005)
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Handout 4.4: Human Body Cavities
Source: SEER Training Modules
Human Body Cavities and Membranes Name of cavity
Principal contents
Membranous lining
Cranial cavity Dorsal body cavity Vertebral canal
Brain
Meninges
Spinal cord
Meninges
Lungs, Heart
Pericardium Pleural Membrane
Abdominal cavity
Digestive organs, spleen, kidneys
Peritoneum
Pelvic cavity
Bladder, Peritoneum reproductive organs
Thoracic cavity Ventral body cavity
Abdominopelvic cavity
Source: SEER Training Modules NMT 04102 Anatomy and Physiology NTA Level 4, Semester 1
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Handout 4.5: Thoracic Cavity and its Divisions
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Handout 4.6: Surface Anatomy of the Abdomen
Source: Gray’s Anatomy 39 Ed.(2005). 1. 2. 3. 4. 5. 6.
Spleen Liver Gallbladder Duodenum Appendix Root of small bowel mesentery
Stomach The stomach lies in a curve within the left hypochondrium and epigastrium although, when distended and pendulous, it may lie as far down as the central or hypogastric regions. The epigastrium is the usual place to auscultate for a 'succussion splash' caused by chronic gastric stasis in upper intestinal obstruction. Duodenum The first part of the duodenum sometimes lies just above the transpyloric plane, depending on its mobility and length. The second part usually lies in the transpyloric plane just to the right of the midline, and the third part usually lies in the subcostal plane across the midline. The fourth part often lies in the transpyloric plane to the left of the midline, although its position varies according to the length of its mesentery. NMT 04102 Anatomy and Physiology NTA Level 4, Semester 1
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Small Bowel and its Mesentery The small bowel is usually referred to as lying in the central umbilical region, but often occupies part of both iliac fossae, both lumbar regions and the hypogastrium. Appendix The appendix is highly variable both in its length and in its position. Its base is commonly referred to as lying beneath a point marked two-thirds of the way along a line joining the umbilicus to the anterior superior iliac spine. Liver The inferior border of the liver extends along a line that passes from the right tenth costal cartilage to the left fifth rib in the midclavicular line. The upper border of the liver follows a line that passes from the fifth rib in the midclavicular line on the right to the equivalent point on the left. This upper border curves slightly downwards at its centre and crosses the midline behind the xiphoid. The right border of the liver is curved to the right and joins the upper and lower right limits. The outline of the liver may be defined by the dull note it gives on percussion when compared with the resonance of the lungs above and the hollow abdominal viscera below. Gallbladder The fundus of the gallbladder is very variable in location. It is commonly identified with the tip of the ninth costal cartilage (in the trans-pyloric plane), near the junction of the linea semi-lunaris with the costal margin. Spleen The spleen lies beneath the ninth, tenth and eleventh ribs on the left side. Its surface markings can be delineated on the lower posterior thoracic wall by defining its axis, which extends from a point 5 cm to the left of the midline at the level of the tenth thoracic spine, and passes laterally along the line of the tenth rib to the mid-axillary line. Pancreas The surface projection of the head of the pancreas lies within the duodenal curve. The neck lies in the transpyloric plane, behind the pylorus in the midline. The body passes obliquely up and left for 10 cm, its left part lying a little above the transpyloric plane. The tail lies a little above and to the left of the intersection of the transpyloric and left lateral planes. Kidney The anterior and posterior surface projections of the kidneys are related to anterior and posterior abdominal wall landmarks. The right kidney lies 1.25 cm lower than the left. On the anterior surface, Ureter The ureter starts on either side approximately at the trans-pyloric plane (the left higher than the right), 5 cm from the midline. Each passes downwards and somewhat medially to enter the bladder at a point marked superficially by the position of the pubic tubercle. NMT 04102 Anatomy and Physiology NTA Level 4, Semester 1
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Abdominal Aorta The abdominal aorta starts just to the left of the midline, at the level of the body of the twelfth thoracic vertebra. It continues downwards for 10 cm as a band 2 cm wide, and bifurcates at the level of the fourth lumbar vertebra (which is marked by the transtubercular plane), 1.5 cm below and to the left of the umbilicus. The pulsations of the aorta can be felt in a thin individual in the supine position by pressing firmly in the midline backwards onto the vertebral column. An easily palpable aorta in an obese person should raise the suspicion of an aneurysm, to be checked by radiological imaging.
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Handout 4.7: The Viscera and the Arrangement of the Peritoneum
Source: Tank, Patrick W.; Gest, Thomas R., 2007
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Worksheet 4.1: Abdominal-Pelvic Regions
Source: Gray’s Anatomy 39
Ed.(2005).
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Session 5:
Anatomical and Physiological Function of the Upper Respiratory System
Total Session Time: 120 Minutes Prerequisites None Learning Tasks By the end of this session, students are expected to be able to: Identify the organs of the upper respiratory system Describe the structure and physiological function of the upper respiratory system Resources needed Flipcharts, Marker pens and masking tapes Black/white board and chalk/whiteboard markers Anatomical charts Anatomical models and atlas OHP and Transparencies or Slide Projector/LCD and Computer Handout 5.1: External Nose Handout 5.2: Bone Structure of the Nose Handout 5.3: Paranasal Sinuses Handout 5.4: The Pharynx Handout 5.5: The Larynx Handout 5.6: Blood supply and Nervous Innervation of Larynx Handout 5.7: The surface anatomy of larynx for more information. Handout 5.8: Rima Glottidis SESISION OVERVIEW Step
Time
Activity/Method
Content
1
05 Minutes
Presentation
Presentation of the Session and Learning Tasks
2
35 Minutes
3
70 Minutes
4
05 Minutes
Presentation
Key Points
5
05 Minutes
Presentation
Evaluation
Presentation, Brainstorm Presentation, Group Discussion
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Organs of the Upper Respiratory System Structure and Physiological Functions of the Upper Respiratory System
Session 5 Anatomical and Physiological Function of the Upper Respiratory System
SESSION CONTENT Step 1: Presentation of Session Title and Leaning Tasks (5 minutes) READ or ASK students to read the Learning tasks and clarify ASK students if they have any questions before proceeding
Step 2: Organs of the Upper Respiratory System (35 minutes)
The main function of the respiratory system is to provide gas exchange between the blood and the environment. Oxygen is essential for cells, which use this vital substance to liberate the energy needed for cellular activities. In addition to supplying oxygen, the respiratory system aids in removing of carbon dioxide, preventing the lethal buildup of this waste product in body tissues. Day-in and day-out, without the prompt of conscious thought, the respiratory system carries out its life-sustaining activities. If the respiratory system’s tasks are interrupted for more than a few minutes, serious, irreversible damage to tissues occurs, followed by the failure of all body systems, and ultimately, death. While the intake of oxygen and removal of carbon dioxide are the primary functions of the respiratory system, it plays other important roles in the body. Helps regulate the balance of acid and base in tissues, a process crucial for the normal functioning of cells. It protects the body against disease-causing organisms and toxic substances inhaled with air. The respiratory system also houses the cells that detect smell, and assists in the production of sounds for speech The respiratory system is divided into two divisions: o Upper respiratory tract; The organs are located outside of the thorax and consists of the nose, pharynx and larynx o Lower respiratory tract; The organs are located within the thorax and consists of the trachea, the bronchial tree and the lungs Organs of the upper respiratory system o Nose o Pharynx o Larynx
Step 3: Structure and Physiological Functions of the Upper Respiratory System (70 minutes)
Structure and Functions of the nose o Structure The nose is the part of the respiratory tract superior to the hard palate and contains the peripheral organ of smell.
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The external portion of the nose consists of a bony and cartilaginous frame covered by skin containing sebaceous glands The two nasal bones meet and are surrounded by the frontal bone to form the root of the nose and is surrounded by the maxillary bone laterally and inferiorly The nasal cavity lies over the roof of the mouth, separated by the palatine bone. Cribriform plate is a portion of the ethmoid bone that separates the roof of the nose from the cranial cavity. The cribriform is perforated by many openings that permit branches of the olfactory nerve responsible for the special sense of smell to enter the cranial cavity and reach the brain. Septum separates the nasal cavity into a right and left cavity. Each nasal cavity is divided into three passageways: Superior meatus Middle meatus Inferior meatus The nose is lined with ciliated columnar epithelium which contains mucus secreting goblet cells. The inferior two thirds of the nasal mucosa is the respiratory area, and the superior one third is the olfactory area. Air passing over the respiratory area is warmed and moistened before it passes through the rest of the upper respiratory tract to the lungs. The olfactory area is specialized mucosa containing the peripheral organ of smell; sniffing draws air to the area
Refer Students to: Handout 5.1: External Nose Handout 5.2: Bone Structure of the Nose
Activity: Small Group Discussion ( 25 minutes) DIVIDE students into small manageable groups ASK students to discussion in groups on functions of the nose for 5 minutes ALLOW groups ask students to provide their response for 2 minutes each CLARIFY and summaries by using the contents below
Functions of the nose o Respiration (breathing). o The nose is the first part of the respiratory system through which the inspired air passes. o The nose humidify, warming, filtering and cleaning of air. o Reception and elimination of secretions from the nasal mucosa, paranasal sinuses, and nasolacrimal ducts. o Olfaction (smelling). o The nose is the organ of sense of smell. o It aids speech- this is enhanced by the presence of paranasal sinuses, which act as resonating chambers for speech.
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Paranasal sinuses Paranasal sinuses are air-filled extensions of the respiratory part of the nasal cavity into the following cranial bones: frontal, ethmoid, sphenoid, and maxilla. They are named according to the bones in which they are located. Each is lined with respiratory mucosa a continuation of mucous membrane lining the nasal cavity. They include: The frontal sinus Maxillary sinuses Sphenoid sinus Ethmoid sinuses Paranasal sinuses reduce the weight of the skull, they also give resonance to the voice These sinuses have clinical importance; The mucous secretion drain from the sinuses into the nasal cavity, if there is infection of the nasal cavity, the swollen mucous membrane of the nasal cavity may block this drainage increasing pressure within a sinus and causing headache Also the infection of upper respiratory tract may extend to the sinuses causing condition called sinusitis
Refer students to Handout 5.3: Paranasal Sinuses Structure and Function of the Pharynx (Throat) Structure The pharynx is a fibromuscular tubelike structure extending from the base of the skull. It lies anterior to the cervical vertebra, roughly corresponds to the levels between C4 to C6. It is the part of the neck and throat situated immediately posterior (behind) to the mouth and nasal cavity, and superior, to the oesophagus, larynx, and trachea. The pharynx is composed of three layers of tissue, namely the inner surface mucous membrane lining, the intermediate fibrous tissue and the outer smooth muscles. The muscles of the pharynx include superior, middle and inferior constrictor muscles It is divided into three parts: o Nasopharynx; lies behind the nasal cavity. It is continuous with lining of the nose and consists of ciliated columnar epithelium. The intermediate layer is fibrous tissue. o Oropharynx; lies behind the oral cavity. It is lined with stratified squamous epithelium which is continuous with lining of the mouth and oesophagus o Laryngopharynx also known as the hypopharynx, this is also lined with moist stratified squamous epithelium, extends from the tip of the epiglottis to the oesophagus. Refer students to Handout 5.4: The Pharynx o Blood supply is from several branches of facial artery. Venous return is into facial and internal jugular vein o The nerve supply is from both parasympathetic and sympathetic. The parasympathetic is from vagus and glossopharyngeal nerves. While the sympathetic is from superior NMT 04102 Anatomy and Physiology NTA Level 4, Semester 1
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cervical ganglia o Seven openings found in the pharynx Right and left Eustachian tube opens into the nasopharynx from the middle ear. Air passes through them to equalize air pressure between the atmosphere and the middle ear. The clinical importance of Eustachian tube is that any infection to the upper respiratory tract can complicate to infection of the middle ear (otitis media) The two posterior nares into the nasopharynx Opening from the mouth known as fauces into oropharynx The opening into the larynx from laryngopharynx The opening into the oesophagus from the laryngopharynx Functions o Passageway for air and food o Warming and humidifying air o Protection o Taste o Facilitates Hearing o The pharynx is also important in vocalization and Speech
Structure and function of the Larynx (Voice Box) Structure The larynx (plural larynges), known as the voice box, is an organ situated in the neck involved in respiration and sound production. It houses the vocal folds, and is situated just below the pharynx between the root of the tongue and upper end of the trachea. Consists of cartilages attaches to each other by ligaments and membranes. The framework of the larynx is formed by nine cartilages connected to one another by muscles, ligaments and membranes. Three cartilages are single (thyroid, cricoid, and epiglottic) and three are paired (arytenoid, corniculate, and cuneiform). The corniculate and cuneiform cartilages appear as small nodules in the posterior part of the aryepiglottic folds Epiglottis is a flap of fibro-elastic cartilage tissue covered with a mucous membrane which is stratified squamous epithelium, attached to the root of the tongue. It projects obliquely upwards behind the tongue and the hyoid bone. It is often incorrectly used to refer to the uvula. This protects the airway during swallowing The inner surface is lined by a ciliated columnar epithelium membrane. Muscles of the Larynx areo Laryngeal muscles are divided into extrinsic and intrinsic groups: The extrinsic laryngeal muscles move the larynx as a whole, these include. The infrahyoid muscles; are depressors of the hyoid and larynx, The suprahyoid and stylopharyngeus muscles are elevators of the hyoid and larynx. The intrinsic laryngeal muscles move the laryngeal parts, making alterations in the length and tension of the vocal folds and in the size and shape of the rima glottidis. All but one of the intrinsic muscles of the larynx are supplied by the recurrent laryngeal nerve, a branch of cranial nerve number ten The cricothyroid muscle is supplied by the external laryngeal nerve, one of the two terminal branches of the superior laryngeal nerve. The actions of the intrinsic laryngeal muscles are described below. NMT 04102 Anatomy and Physiology NTA Level 4, Semester 1
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The intrinsic muscle of the larynx, are important in controlling vocal cord length and tension in regulating the shape of laryngeal inlet, these include: Crico-thyroid muscle lengthens and stretches the vocal cords. Posterior cricoarytenoid muscle abducts the vocal cords. Lateral cricoarytenoid muscle adducts the vocal cords. Thyroarytenoid muscle (also called vocalis muscle) shortens vocal cords. Transverse arytenoid muscle adducts the vocal folds. Blood supply is through superior and inferior laryngeal arteries. Venous drainage is by thyroid veins which join the internal jugular Nerve innervations is through parasympathetic and sympathetic fibres; The parasympathetic supply is from superior and recurrent laryngeal nerve which is the branch of vagus nerve. Sympathetic is from superior cervical ganglia.
Refer students to: Handout 5.5: The Larynx Handout 5.6: Blood Supply and Nervous Innervations of Larynx Handout 5.7: The surface anatomy of larynx
Functions o Respiration; It filters, humidifies and warms air as it passes to the lungs o Swallowing; The epiglottis and vestibular folds prevent swallowed material from moving into the larynx o Phonation; the vocal folds are the primary source of sound production. o It serves as the organ of voice production- the pitch of the voice depends upon the length and tightness of the cords. o Sound has the properties of pitch, volume and resonance. Pitch of the voice depends upon the length and tightness of the cord. Volume of the voice depends upon the force with which the cords vibrate. The greater the force of expired air the more the cords vibrates and the louder the sound emitted. Resonance or tone is dependent upon the shape of the mouth, the position of the tongue and the lip, facial muscles and the air in the paranasal sinuses. Speech - This occurs during expiration when the sound produced by the vocal cords is manipulated by the tongue, cheeks and the lips. Refer students to Handout 5.8: Rima Glottidis
Step 4: Key Points (5 minutes)
The respiratory system is divided into two: the upper and the lower respiratory system The organs of the upper respiratory system includes the nose, pharynx, and the larynx All this organs function together as air passage, and they help in filtering air as well as playing part in production of voice. The respiratory and circulatory systems work together to deliver oxygen to cells and remove carbon dioxide in a two-phase process called respiration.
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Step 5: Evaluation (5 minutes)
Mention the organs of the lower respiratory system What are the functions of the nose? Mention the function of the pharynx Mention the functions of the Larynx Name the intrinsic muscles of the larynx
ASK students if they have any comments or need clarification on any points
References
Drake, R. L., Vogl, W. & Mitchell, A. W. M. (2007). Gray’s Anatomy for Students. United Kingdom: Churchill Livingstone Elservier Moore, K. L. & Agur, A. M. R. (2007). Essential Clinical Anatomy (3rd Ed.). Lippincott Williams & Wilkins Seeley, R. R., Stephens. T. D. & Tate, P. (2003) Anatomy and Physiology. New York: McGraw-Hill Shier, A., Butler, J. & Lewis, R. (2004). Hole’s Human Anatomy & Physiology. New York: McGraw-Hill Standring, S. (2008). Grays’s Anatomy The Anatomical Basis of Clinical Practice. United Kingdom: Churchill Livingstone Elservier. Thibodeau, G. A. & Patton, K. T. (1999). Anatomy & Physiology. Saint Louis: Mosby and Von Hoffman Press, Inc Waugh, A. & Grant, A. (2006). Ross and Willson Anatomy and physiology in Health and illness. United Kingdom: Churchill Livingstone Elservier.
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Handout 5.1: External Nose
Source: Tank, Patrick W.; Gest, Thomas R., 2007
Source: Gray’s Anatomy 39
Ed.(2005).
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Handout 5.2: Bone Structure of the Nose
Source: Gray’s Anatomy 39
Ed.(2005).
Source: Tank, Patrick W.; Gest, Thomas R., 2007 NMT 04102 Anatomy and Physiology NTA Level 4, Semester 1
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Handout 5.3: Para nasal Sinuses
Source: Tank,
Patrick W.; Gest, Thomas R, 2007
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Handout 5.4: The Pharynx
Source: Tank, Patrick W.; Gest, Thomas R. (2007)
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Handout 5.5: The Larynx
Source: Gray’s Anatomy 39
Ed.(2005).
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Handout 5.6: Blood Supply and Nervous Innervations of Larynx
Source: Tank, Patrick W.; Gest, Thomas R., 2007
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Handout 5.7: The Surface Anatomy of Larynx
Source: Gray’s Anatomy 39
Ed.(2005).
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Handout 5.8: Rima Glottidis
Source: Grays Anatomy 2005
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Session 5 Anatomical and Physiological Function of the Upper Respiratory System
Session 6:
Function of the Lower Respiratory System
Total Session Time: 120 Minutes Prerequisites None Learning Tasks By the end of this session, students are expected to be able to: Identify the organs of the lower respiratory system Describe the structure and physiological function of the lower respiratory system Resources Needed Flipcharts, Marker pens and Masking tape Black/white board and chalk/whiteboard markers Anatomical models and atlas LCD and Computer Handouts 6.1 Trachea and Main Bronchi Handout 6.2 Major Bronchial Division Handout 6.3 The Lungs Handout 6.4 The Respiratory Membrane Handout 6.5 Pulmonary Circulation Handout 6.6 Pulmonary Innervations Handout 6.7 The Pleural SESSION OVERVIEW Step
Time
Activity/Method Presentation
Session Content Presentation of Session Title and Learning Tasks
1
05 Minutes
2
30 Minutes
3
70 Minutes
4
10 Minutes
Presentation
Key Points
5
05 Minutes
Presentation
Evaluation
Presentation, Buzz Presentation, Group Discussion
Organs of the Lower Respiratory System Structure and Physiological Functions of Lower Respiratory Systems
SESSION CONTENT Step 1: Presentation of Session Title and Leaning Tasks (5 minutes) READ or ASK students to read the related tasks and clarify ASK students if they have any questions before proceeding
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Session 6 Function of the Lower Respiratory System
Step 2: Organs of the Lower Respiratory System (30 minutes) Activity: Buzzing (05 minutes) ASK the students to pair up and list the organs of lower respiratory system for 2 minutes ALLOW few student to responses and let other pairs to provide unmentioned responses WRITE their response on the flip chart/board CLARIFY and summaries by using the information below
Organs of the lower respiratory system are: o The trachea o The bronchial Tree o The lungs o Pleura and pleural cavity
Step 3: Structure and Physiological Functions of Lower Respiratory Systems (30 minutes) Activity: Small Group Discussion ( 25 minutes) DIVIDE students into small manageable groups ASK students to discussion in groups on the structures and physiological functions of lower respiratory system for 10 minutes ALLOW groups ask students to provide their response for 2 minutes each CLARIFY and summaries by using the contents below The Trachea A tube formed of cartilage and fibromuscular membrane, lined internally by mucosa. The anterolateral portion is made up of incomplete rings of cartilage, and the posterior aspect by a flat muscular wall. It descends from the larynx from the level of the sixth cervical vertebra to the upper border of the fifth thoracic vertebra, where it divides into right and left principal (pulmonary) bronchi. It lies approximately in the saggital plane, but its point of bifurcation is usually a little to the right. The trachea is mobile and can rapidly alter in length: thus, during deep inspiration, the bifurcation may descend to the level of the sixth thoracic vertebra into Behind the cervical trachea is the oesophagus, which runs between the trachea and the vertebral column. The recurrent laryngeal nerves ascend on each side, in or near the grooves between the sides of the trachea and oesophagus. The lateral relations of the trachea are the paired lobes of the thyroid gland, which descend to the fifth or sixth tracheal cartilage In the mediastinum, at the level of the fifth thoracic vertebra, the trachea divides into the right and left primary bronchi NMT 04102 Anatomy and Physiology NTA Level 4, Semester 1
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The right main bronchus is wider, shorter, and runs more vertically than the left main bronchus as it passes directly to the hilum of the lung. Refer students to Handout 6.1: Trachea and Main Bronchi
The Bronchial Tree A bronchus (plural bronchi, adjective bronchial). It conducts air into the lungs. It is made up of hyaline cartilage No gas exchange takes place in this part of the lungs. It is lined by the mucous membrane which undergoes a transition from ciliated pseudo stratified columnar epithelium to simple cuboidal epithelium to simple squamous epithelium The left main bronchus subdivides into two lobar bronchi while the right main bronchus divides into three. The left main bronchus passes inferolaterally, inferior to the arch of the aorta and anterior to the esophagus and thoracic aorta, to reach the hilum of the lung The right principal bronchus is wider, shorter and more vertical than the left, being 2.5 cm long: this explains why inhaled foreign bodies enter it more often than the left. The right main bronchus gives rise to its first branch, the superior lobar bronchus, and then enters the right lung opposite the fifth thoracic vertebra. After giving off the superior lobar bronchus, which arises posterosuperior to the right pulmonary artery, the right main bronchus crosses the posterior aspect of the artery, enters the pulmonary hilum poster inferior to it, and divides into middle and an inferior lobar bronchus. The lobar bronchi divide into tertiary bronchi. o Each of the segmental bronchi supplies a broncho-pulmonary segment. A broncho-pulmonary segment is the area of lung supplied by a segmental bronchus and its accompanying pulmonary artery branch. A broncho-pulmonary segment is the smallest, functionally independent region of a lung and the smallest area of lung that can be isolated and removed without affecting adjacent regions. Tributaries of the pulmonary vein tend to pass intersegmentally between and around the margins of segments. Each bronchopulmonary segment is shaped like an irregular cone with the apex at the origin of the segmental bronchus and the base projected peripherally onto the surface of the lung. o There are ten segments per lung, but due to anatomic development, several segmental bronchi in the left lung fuse, giving rise to eight. The segmental bronchi divide into many primary bronchioles which divide into terminal bronchioles, each of which then gives rise to several respiratory bronchioles, which go on to divide into 2 to 11 alveolar ducts. There are no glands or cartilage in any of the bronchioles, and the epithelial cells become more cuboidal in shape. There are 5 or 6 alveolar sacs associated with each alveolar duct. The alveolus is the basic anatomical unit of gas exchange in the lung. Refer students to Handout 6.2: Major Bronchial Divisions for more information.
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The Lungs Are the vital organs of respiration Their main function is to oxygenate the blood by bringing inspired air into close relation with the venous blood in the pulmonary capillaries. The healthy lungs in living people are normally light, soft, and spongy. They are also elastic and recoil to about one third their size when the thoracic cavity is opened They are situated on either side of the heart and other mediastinal contents in the thoracic cavity. At birth the lungs are pink, but in adults they are dark grey and patchily mottled. As age advances this maculation becomes black, as granules of inhaled carbonaceous material are deposited in the loose connective tissue near the lung surface. The adult right lung usually weighs 625 g, and the left 565 g, but they vary greatly. Their weight also depends on the amount of blood or serous fluid contained within them. In proportion to body stature, the lungs are heavier in men than in women. Each lung has an apex, base, three borders and two surfaces. In shape each lung approximates to half a cone. The right lung is divided into superior, middle and inferior lobes by an oblique and a horizontal fissure. The left lung is divided into a superior and an inferior lobe by an oblique fissure which extends from the costal to the medial surfaces of the lung both above and below the hilum. The lobes are further divided into functional units; the bronchopulmonary segments The diaphragm rises higher on the right to accommodate the liver, and so the right lung is vertically shorter (by 2.5 cm) than the left The bronchopulmonary segments are subdivided into lobules by incomplete connective tissue walls. The lobules are supplied by bronchioles. Approximately 300 million alveoli are in the two lungs.. o Two types of cells form the alveolar wall Type I pneumocytes; are thin squamous epithelial cells that form 90% of the alveolar surface. Most gas exchange between alveolar air and the blood takes place through these cells Type II pneumocytes; are round or cube-shaped secretory cells that produce surfactant, which makes easier for the alveoli to expand during inspiration. o Since lungs are the principal organs of respiration, it has the respiratory membrane where gas exchange between the air and the lungs takes place. o The respiratory membrane of the lung is very thin and it consists of : A thin layer of fluid lining the alveolus The alveolar epithelium composed of simple squamous epithelium The basement membrane of the alveolar epithelium A thin interstitial space The basement membrane of the capillary endothelium The capillary endothelium composed of simple squamous epithelium
Refer Students to: Handout 6.3: The Lung Handout 6.4: The Respiratory Membrane
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Blood Supply to the Lungs Each lung has a large pulmonary artery supplying blood to it and two pulmonary veins draining blood from it. The right and left pulmonary arteries arise from the pulmonary trunk at the level of the 77 nnerv angle. The pulmonary arteries carry poorly oxygenated (venous) blood to the lungs for oxygenation. The pulmonary arteries pass to the corresponding root of the lung and give off a branch to the superior lobe before entering the hilum. Within the lung, each artery descends posterolateral to the main bronchus and divides into lobar and segmental arteries. Consequently, an arterial branch goes to each lobe and bronchopulmonary segment of the lung, usually on the anterior aspect of the corresponding bronchus. The pulmonary veins, two on each side, carry well-oxygenated (arteria) blood from the lungs to the left atrium of the heart. Beginning in the pulmonary capillaries, the veins unite into larger and larger vessels. Intrasegmental veins drain blood from adjacent bronchopulmonary segments into the intersegmental veins in the septa, which separate the segments. A main vein drains each bronchopulmonary segment, usually on the anterior surface of the corresponding bronchus. The bronchial arteries supply blood to the structures making up the root of the lungs, the supporting tissues of the lung, and the visceral pleura. The left bronchial arteries arise from the thoracic aorta; however, the right bronchial artery may arise from: o A superior posterior 77nnervations artery. o A common trunk from the thoracic aorta with the right 3rd posterior 77nnervations artery. o A left superior bronchial artery. The small bronchial arteries provide branches to the superior esophagus and then pass along the posterior aspects of the main bronchi, supplying them and their branches as far distally as the respiratory bronchioles. The distal most branches of the bronchial arteries anastomose with branches of the pulmonary arteries in the walls of the bronchioles and in the visceral pleura. The bronchial veins drain only part of the blood supplied to the lungs by the bronchial arteries, primarily that distributed to or near the more proximal part of the root of the lungs The remainder of the blood is drained by the pulmonary veins. The right bronchial vein drains into the azygos vein, and the left bronchial vein drains into the accessory hemiazygos vein or the left superior innervations vein. Refer Students to Handout 6.5: Pulmonary Circulation Nervous Innervations of the Lungs The nerves of the lungs and visceral pleura derive from the pulmonary plexuses located anterior and (mainly) posterior to the roots of the lungs. These nerve networks contain parasympathetic fibers from the vagus nerves (CN X) and sympathetic fibers from the sympathetic trunks. Parasympathetic ganglion cells, cell bodies of postsynaptic parasympathetic neurons are in the pulmonary plexuses and along the branches of the bronchial tree. NMT 04102 Anatomy and Physiology NTA Level 4, Semester 1
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The parasympathetic fibers from CN X are motor to the smooth muscle of the bronchial tree (bronchoconstrictor), inhibitory to the pulmonary vessels (vasodilator), and secretory to the glands of the bronchial tree (secretomotor). The visceral afferent fibers of CN X are distributed to the: Bronchial mucosa and are probably concerned with tactile sensation for cough reflexes. Bronchial muscles, possibly involved in stretch reception. Interalveolar connective tissue, in association with Herring-Breuer reflexes (mechanism that tends to limit respiratory excursions). Pulmonary arteries serving pressor receptors (blood pressure) and pulmonary veins serving chemoreceptors (blood gas levels). Sympathetic ganglion cell bodies of postsynaptic sympathetic neurons are in the paravertebral sympathetic ganglia of the sympathetic trunks. The sympathetic fibers are inhibitory to the bronchial muscle (bronchodilator), motor to the pulmonary vessels (vasoconstrictor), and inhibitory to the alveolar glands of the bronchial tree. This has clinical importance in bronchial asthma management. Refer Students to Handout 6.6: Pulmonary Innervations
Pleura and Pleural Cavity Each lung is invested by and enclosed in a serous pleural sac that consists of two continuous membranes the pleurae o The visceral pleura (pulmonary pleura) covers the lungs and is adherent to all its surfaces, including the surfaces within the horizontal and oblique fissures; it cannot be dissected from the lungs. o The parietal pleura line the pulmonary cavities, adhering to the thoracic wall, the mediastinum, and the diaphragm. The pleural cavity the potential space between the visceral and the parietal layers of pleura contains a capillary layer of serous pleural fluid, which lubricates the pleural surfaces and allows the layers of pleura to slide smoothly over each other during respiration. Its surface tension also provides the cohesion that keeps the lung surface in contact with the thoracic wall; consequently, the lung expands and fills with air when the thorax expands while still allowing sliding to occur, much like a layer of water between two glass plates. The parietal pleura consists of four parts o Costal part (pleura) covers the internal surfaces of the thoracic wall (sternum, ribs, costal cartilages, 78 nnervations, muscles and membranes, and side of thoracic vertebrae) and is separated from the wall by endothoracic fascia. o Mediastinal part (pleura) covers the lateral aspects of the mediastinum (the central compartment of the thoracic cavity). o Diaphragmatic part (pleura) covers the superior or thoracic surface of the diaphragm on each side of the mediastinum. The parietal pleura are highly sensitive to pain; the visceral pleura are not due to its lack of sensory innervations. Pleural fluid o Pleural fluid is a sereous fluid produced by the pleurae. o In normal pleurae, most fluid is produced by the parietal circulation (intercostal NMT 04102 Anatomy and Physiology NTA Level 4, Semester 1
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o o o o o
arteries) via bulk flow and reabsorbed by the lymphatic system. Thus, pleural fluid is continuously produced and reabsorbed. There is no anatomical connection between the left and right pleural cavities, so in cases of pneumothorax, the other hemithorax will still function normally. The pleurae are coated with lubricating pleural fluid which allows the pleurae to slide effortlessly against each other during ventilation. Surface tension of the pleural fluid also leads to close apposition of the lung surfaces with the chest wall. This physical relationship allows for optimal inflation of the alveoli during respiration. Refer students to Handout 6.7: The Pleura
Step 5: Key Points (5 minutes)
The lower respiratory system is made up of the trachea, bronchial tree and the lungs The lungs are the main organs of respiration The left main bronchus subdivides into two lobar bronchi while the right main bronchus divides into three.
Step 6: Evaluation (5 minutes)
Mention the organs of the lower respiratory system What is the main organ of respiration? What are the functions of the lungs
ASK students if they have any comments or need clarification on any points
References
Drake, R .L., Vogl, W. & Mitchell, A. W. M. (2007). Gray’s Anatomy for Students. United Kingdom: Churchill Livingstone Elservier Moore, K. L. & Agur, A. M. R. (2007). Essential Clinical Anatomy, 3rd Edition Lippincott Williams & Wilkins Seeley, R. R., Stephens, T. D. & Tate, P. (2003) Anatomy and Physiology. New York: McGraw-Hill Shier, A., Butler, J. & Lewis, R. (2004). Hole’s Human Anatomy & Physiology. New York: McGraw-Hill Standring, S. (2008). Grays’s Anatomy The anatomical basis of clinical practice. United Kingdom: Churchill Livingstone Elservier. Thibodeau, G. A. & Patton K. T. (1999). Anatomy & Physiology. Saint Louis: Mosby and Von Hoffman Press, Inc Venes, D. (2001). Taber’s Cyclopedic Medical Dictionary. (19th Ed.). F.A. Davis company,Philadelphia Waugh, A. & Grant, A. (2006). Ross and Willson Anatomy and physiology in Health and illness. United Kingdom: Churchill Livingstone Elservier.
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Handout 6.1: Trachea and Main Bronchi
Source: Grays Anatomy 2007
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Handout 6.2: Major Bronchial Divisions
Source: Grays Anatomy 2007.
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Source: Grays Anatomy 2005.
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Handout 6.3: The Lung Lobes
Source: Lippincott Williams & Wilkins, 2007
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Handout 6.4: The Respiratory Membrane
Source: Grays Anatomy 2005.
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Handout 6.5: Pulmonary Circulation
Source: Tank, Patrick W.; Gest,2007 Thomas Source: Lippincott Williams & Wilkins,
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Handout 6.6: Pulmonary Innervations
Source: Grays Anatomy 2007
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Source: Tank, Patrick W.; Gest, Thomas R, 2007
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Handout 6.7: The Pleura
Source: Tank, Patrick W.; Gest, Thomas R, 2007
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Session 7:
Structure and Physiological Function of the Urinary System
Total Session Time: 120 Minutes Prerequisites None Learning Tasks By the end of this session, students are expected to be able to: Identify the organs of the urinary system Describe the structure and physiological function of the urinary system Resources Needed Flipcharts, Marker pens and Masking tape Black/white board and chalk/whiteboard markers Anatomical models and atlas LCD and Computer Anatomy Models Handout 7.1: The Kidney Handout 7.2: Kidney Blood Supply Handout 7.3: The Nephron Handout 7.4: Functions of Nephron Components Handout 7.5: Steps of Urine Formation Handout 7.6: Kidneys and Ureter Blood Supply Handout 7.7: The Urinary Bladder Handout 7.8: The Urethra SESSION OVERVIEW Step
Time
Activity/Method
1
05 Minutes
Presentation
2
25 Minutes
3
80 Minutes
4
05 Minutes
Presentation
Key Points
5
05 Minutes
Presentation
Evaluation
Presentation of Session Title and Learning Tasks
Presentation, Buzz Presentation, Group Discussion
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Session 7 Structure and Physiological Function of the Urinary System
SESSION CONTENT Step 1: Presentation of Session Title and Learning Tasks (5 minutes) READ or ASK students to read the Learning tasks and clarify ASK students if they have any questions before proceeding
Step 2: Organs of the Urinary System (25 minutes) Activity: Buzzing (15 minutes) ASK the students to pair up and list the principal and accessory organs of the urinary system for five minutes ALLOW few student to responses and let other pairs to provide unmentioned responses CLARIFY and summaries by using the information below
Urinary system is the system which regulates the content of blood plasma to maintain the homeostasis of the internal fluid environment within normal limits (control the composition of blood and blood volume). It removes waste products from the blood, of which many of them are toxic. The urinary system is the main excretory system and consist the following organs o 2 kidneys - principal organs of the urinary system which secrete urine o Accessory organs which includes: Ureters, which convey the urine from the kidney to the urinary bladder Urinary bladder where urine collects and is temporary stored Urethra, through which the urinary is discharged from the urinary bladder to the exterior
Step 3: Structure and Physiological Functions of the Urinary System (80 minutes) Activity: Small Group Discussion ( 20 minutes) DIVIDE students into small manageable groups ASK students to discussion in groups on the structure and physiological functions of the urinary system for 10 minutes ALLOW groups students to provide their response for 2 minutes each CLARIFY and summaries by using the contents below The Kidneys Anatomical location o The kidneys lie in retroperitoneal position i.e. lies posterior to parietal peritoneum. o They are located in either side of the vertebral column and extend from the level of NMT 04102 Anatomy and Physiology NTA Level 4, Semester 1
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the last thoracic vertebra (T12) to the third lumbar (L3) usually the right kidney is a little lower than the left, because of the liver which lies superior to the right kidney. o The kidney is encased with the cushion of fat which help it to be in position o Structure of the kidney The kidneys are bean shaped organs with a medial indentation. An average size is approximately 11cm by 7cm by 3 cm. The left kidney is often slightly larger than the right. The medial surface of each kidney has a concave notch called the hilum, where the renal artery and nerves enter and renal vein ureter exit the kidney The kidney is covered by a thin connective tissue membrane called capsule. The renal capsule is a smooth, transparent, fibrous membrane that surrounds, encloses, and protects the kidney. The renal capsule is itself surrounded by a mass of fatty tissue that also helps to protect the kidney by damage by cushioning it in cases of impact or sudden movement small part of the superior pole, on its medial side, is covered by the left suprarenal gland o Cross-section of the kidney There are three major regions of the kidney, renal cortex, renal medulla and the renal pelvis. The Renal cortex is the outer part of the kidney. It has a smooth texture and is the location of the Bowman's Capsules and the glomeruli, in addition to, the proximal and distal convoluted tubules and their associated blood supplies. The Renal medulla is the inner part of the kidney. "Medulla" means "inner portion". This area has striated triangular structures called "Renal Pyramids”. The appearance of striations is due to many straight tubules and blood vessels within the renal pyramids. The Renal pelvis is the funnel-shaped basin (cavity) that receives the urine drained from the kidney nephrons via the collecting ducts and then the (larger) papillary ducts. The Renal hilus is an indentation near to the centre of the concave area of the kidney. This is the area of the kidney through which the ureter and the other structures including blood vessels (illustrated), lymphatic vessels, and nerves enter/leave the kidney. Refer Students to Handout 7.1: The Kidney o Kidneys are highly vascular. The large branch which bring blood to the kidney is the renal artery a branch of abdominal aorta Entering the kidney it divides into segmental arteries, then interlobar arteries between the pyramids, these arteries extend toward the cortex, arch over the base of the pyramid and form arcuate arteries. From arcuate arteries the interlobular arteries penetrate the cortex. Branches of interlobular arteries are the afferent arterioles branching into capillary network called glomeruli Efferent arterioles are formed from the glomerular capillaries. The efferent arterioles give rise to peri-tubular capillaries (vasa recta), around the proximal and NMT 04102 Anatomy and Physiology NTA Level 4, Semester 1
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distal tubules. The peritubular capillaries drain into the interlobular vein then the interlobar vein then into the renal vein. The renal vein connects to the inferior venacava.
Refer students to Handout 7.2: Kidney Blood Supply o Functions of the Kidney The kidneys are the major excretory organs of the body. The skin, liver, lung and intestine eliminate some waste products, but if the kidneys fail to function, these other excretory organs cannot adequately compensate. o The following functions are performed by the kidney: Filtering of blood. Protein and blood cells are retained in the blood, while a large volume of filtrate is produced. Most of the filtrates volume is reabsorbed back into the blood along with useful molecules and ions. Small volume of water, metabolic wastes, toxic molecules, and excess ions remain in the filtrates and the result is the formation of urine Regulation of blood pressure The kidneys regulate blood pressure by adjusting the volume of blood in the body through, renin-angiotensin-aldosterone mechanism and the action of Ant diuretic hormone Regulation of blood volume. The kidneys play a major role in controlling the extracellular fluid volume in the body by producing either large volume of dilute urine or small volume of concentrated urine. Regulation of the plasma electrolytes. The kidneys also regulate the quantities of plasma solutes. Important examples of such electrolytes regulated by the kidney are sodium ions (Na+), potassium ions (K+), calcium ions (Ca2+), chloride ions (Cl-), and phosphate ions (HPO4-2). Regulation of the pH of the blood. The kidneys secrete H+ ions to help regulate blood pH. At the same time, the kidneys also conserve bicarbonate ions (HCO3-), which are an important buffer of H+. Synthesis of Vitamin D. The kidneys synthesize calcitrol, which is the active form of vitamin D. Production of Red blood cells. The kidneys contribute to the production of red blood cells by releasing the hormone erythropoietin which stimulates Erythropoiesis (the production of red blood cells). Excretion of waste products and foreign substances. The kidneys excrete waste products of metabolism in form urine. Examples of waste products from metabolic reactions within the body include Urea (from the breakdown of amino acids), bilirubin in a form of Urobilinogen (from the breakdown of hemoglobin), and creatinine (from the breakdown of creatinine phosphate in muscle fibers). NMT 04102 Anatomy and Physiology NTA Level 4, Semester 1
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o Structure and Functions of Nephron Kidney nephrons are the functional units of the kidneys. That is, it is the kidney nephrons that actually perform the kidney's main functions. There are approximatly a million nephrons within each kidney There are two parts of a kidney nephron: Renal corpuscle which has; (the renal corpuscle is the part of the kidney nephron in which blood plasma is filtered). It has two parts: Glomerulus which is a network of small blood vessels called capillaries Within the glomerulus are glomerular capillaries that are located between the afferent arteriole (bringing blood into the glomerulus) and the efferent arteriole (draining blood away from the glomerulus). For filtration to occur, the (outgoing) efferent arteriole has a smaller diameter than the (incoming) afferent arteriole. This difference in arteriole diameters helps to raise the blood pressure in the glomerulus Bowman’s capsule which is the double-walled epithelial cup within which the glomerulus is contained. Bowman's capsule is the blind expanded end of a renal tubule. It is a doublewalled epithelial cup lined by a simple squamous epithelium on its outer (parietal) wall; its glomerular, juxtacapillary (visceral) wall is composed of specialized epithelial the podocytes. The area between the double-walls of the Bowman's capsule is called the capsular space; a continuous with the proximal convoluted tubule The glomerular endothelium is finely fenestrated This membrane is formed by several layers of cells clustered together Its function is Filtration of blood. Renal tubules; is the part of the kidney nephron into which the glomerular filtrate passes after it has reached the Bowman's capsule. Portions of the renal tubules are: Proximal convoluted tubule Loop of henle, it has got two parts, namely: Descending limb Ascending limb Distal convoluted tubule Collecting duct The main function of nephron is filtration and reabsorption of essential elements required by the body. In doing so it maintains the homeostasis. Urine Formation Process of forming Urine Filtration The first part of the process of urine formation occurs in the glomeruli. The glomeruli act as filters, allowing water, glucose, salt and waste materials to pass through to the Bowman's capsule, which surrounds each glomerulus, but preventing the red blood cells from passing. The fluid in the Bowman's capsule is referred to as the nephric filtrate and resembles blood plasma. It also includes urea, produced from the ammonia which accumulates when the liver NMT 04102 Anatomy and Physiology NTA Level 4, Semester 1
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processes amino acids and is filtered out by the glomeruli. Reabsorption About 43 gallons of fluid goes through the filtration process, but most is subsequently reabsorbed rather than being eliminated. Reabsorption occurs in the proximal tubules of the nephron, which is the portion beyond the capsule, in the loop of Henle, and in the distal and collecting tubules, which are further along the nephron beyond the loop of Henle. Water, glucose, amino acids, sodium and other nutrients are reabsorbed into the bloodstream in the capillaries surrounding the tubules. Water moves via the process of osmosis: movement of water from an area of higher concentration to one of lower concentration. Usually all the glucose is reabsorbed, but in diabetic individuals, excess glucose remains in the filtrate. Sodium and other ions are reabsorbed incompletely, with a greater proportion remaining in the filtrate when more is consumed in the diet, resulting in higher blood concentrations. Hormones regulate the process of active transport by which ions like sodium and phosphorus are reabsorbed. Secretion Secretion is the final step in the process of urine formation. Some substances move directly from the blood in capillaries around the distal and collecting tubules into those tubules. Secretion of hydrogen ions via this process is part of the body's mechanism for maintaining proper pH, or acid-base balance. More ions are secreted when the blood is acidic, less when it is alkaline. Potassium ions, calcium ions and ammonia also are secreted at this stage, as are some medications. The urine created by this process then passes to the central part of the kidney called the pelvis, where it flows into the ureters and then the bladder.
Refer students to: Handout 7.3: The Nephron Handout 7.4: Functions of Nephron Components Handout 7.5: Steps of Urine Formation
The Ureters The ureters are the tubes that convey urine from kidneys to urinary bladder. They are about 25-30 cm long with a diameter of about 3mm. Is continuous with the funnel shaped renal pelvis It passes behind the peritoneum in front of the psoas muscles into the pelvic cavity, and passes obliquely through the posterior walls of the bladder. When urine accumulates, the pressure in the bladder rises. The ureters are compressed and openings are occluded, this prevents reflex of urine from the ureters to the kidney Ureters consist of three layers: o An outer covering layer of fibrous tissues which continues with fibrous capsule of the kidney NMT 04102 Anatomy and Physiology NTA Level 4, Semester 1
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o Middle muscular layer; consist of interlacing smooth muscle fibers that form a functional unit spiraling around the ureters in clockwise and ant clockwise direction. The lower third of the ureters contains longitudinal muscles o The inner mucosa layer, is composed of transitional epithelium Ureters propel urine from the kidneys to the bladder by peristaltic contraction of the smooth muscle layer. This originates in the pacemaker in minor calyces and not under autonomic nerve control. Blood supply is through testicular and ovarian arteries, branches internal iliac artery. Refer Students to Handout 7.6: Kidneys and Ureters Blood Supply
Urinary Bladder o Is the reservoir for urine o It lies in the pelvic cavity o Its size and position varies depending on the volume of urine it contains, when distended it rises into the abdominal cavity. o Is pear shaped, but becomes oval when filled with urine o It opens to the urethra at its lowest point-neck o Superiorly it is covered by peritoneum, posteriorly it surrounds the uterus in female and rectum in male o The urinary bladder is composed of three layers; Outer layer of loose connective tissues, containing blood lymphatic vessels and nerves The middle layer, consist of interlacing smooth muscle fibers and elastic tissue arranged in three layers. This is called destrusor muscle which when contracts empty the bladder. The mucosa layer composed of transitional epithelium. o The three orifices in the bladder wall form a triangle or trigon; the upper 2 orifices are ureters and the lower opening is for Urethra. o The internal urethra sphincter (thickening of the urethral smooth muscle layer) controls outflow of urine from the bladder. Refer Students to Handout 7.7: The Urinary Bladder
Urethra o Is a canal extending from the neck of the bladder to the exterior at the external urethra orifice o In male is longer (19-20cm) than in females (4cm) o The male urethra is associated with the urinary and the reproductive system, it consist of three parts; Prostatic urethral, which originate from the bladder and pass through the prostate gland Membranous Urethral, is the shortest and narrowest extend from the prostate gland to the bulb of the penis Penile or spongiose, lies within the corpus spongiosum of the penis and terminates at the external urethral orifice in the glans penis. o Female urethral runs behind the symphysis pubis and opens at the external urethral orifice infront of the vagina.
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o The external urethral orifice is guarded by external urethral sphincter which is under voluntary control. Refer Students to Handout 7.8: The Urethra
Step 4: Key Points (5 minutes)
Urinary system is the system which regulates the content of blood plasma to maintain the homeostasis of the internal fluid environment within normal limits. Urinary system is the main system of excretion where the principal organ of excretion is the kidney Kidney Nephron is the functional units of the kidneys. The accessory organs of urinary system includes the ureters, bladder, and urethra The male urethra is associated with the urinary and the reproductive system
Step 5: Evaluation (5 minutes)
Explain the process of urine formation Mention parts of the nephron What are functions of the Kidney?
ASK students if they have any comments or need clarification on any points
References
Drake, R. L., Vogl, W., & Mitchell, A. W. M (2007). Gray’s Anatomy for Students, United Kingdom: Churchill Livingstone Elservier Moore, K. L. & Agur, A. M. R. (2007). Essential Clinical Anatomy.(3rd ed). Lippincott Williams & Wilkins Seeley, R. R., Stephens, T. D. & Tate, P. (2003). Anatomy and Physiology. New York: McGraw-Hill Shier, A., Butler, J. & Lewis, R. (2004). Hole’s Human Anatomy & Physiology. New York: McGraw-Hill Standring, S. (2008). Grays’s Anatomy The Anatomical Basis of Clinical Practice. United Kingdom: Churchill Livingstone Elservier. Thibodeau, G. A., Patton, K. T. (1999). Anatomy & Physiology. Saint Louis: Mosby, Von Hoffman Press, Inc Waugh, A. & Grant, A. (2006). Ross and Willson Anatomy and physiology in Health and illness. United Kingdom: Churchill Livingstone Elservier.
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Handout 7.1: The Kidney
Source: Grays Anatomy 2007
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Handout 7.2: Kidney Blood Supply
1 – Renal corpuscle 4 – Ascending limb 6 – Collecting duct 7 – Arcuate artery 8– Interlobular artery 9– Afferent artery
10 12 24 25 A B
– Efferent artery – Vasa recta – Papillary duct – Interlobar artery – Medulla – Cortex
Source: A.D.A.M. online image
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Handout 7.3: The Nephron
Source: Gray1128.png
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Handout 7.4: Functions of Nephron Components
Source McGraw-Hill companies, Inc
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Handout 7.5: Urine Formation Steps Filtration The first step in formation of urine is filtration. Filtration is the process by which the blood that passes through the glomerulus is filtered out, so that only certain structures pass through into the proximal convoluted tubule. The rate at which the blood is filtered is known as the glomerular filtration rate, which is normally 125 ml/minute or 180 liters/day! The glomerulus lining is such that it only allows small molecules to filter through, like glucose, plasma, ions like sodium and potassium, urea, etc. The larger molecules, like blood cells and protein cannot pass through the glomerulus. This is the reason that when there are kidney diseases, the glomerulus lining is affected, due to which the protein molecules also pass through, leading to blood and protein in urine. Selective Reabsorption As mentioned above, in filtration step of urine formation, there is only crude and elementary separation of waste products and a lot of water, glucose and other important materials also pass through. Thus, there is need for reabsorption of these important elements back into the body, which is where the second step, that is reabsorptions, comes in. This step is known as selective reabsorption because only some elements are reabsorbed back into the body. Reabsorption occurs in two steps, which is active reabsorption (which requires energy) and passive reabsorption (which does not require energy). Due to the difference in concentration of the fluid inside and outside the tubules, 99% of the water returns into circulation and thus, is passively absorbed, which is important for urine formation and flow. Provided the glucose levels are normal, almost all of the glucose is reabsorbed back into the blood from the proximal tubules. This glucose is actively transported into the peritubular capillaries. However, when there is a very large amount of glucose in the blood, then some of it passes into the urine, which is one of the signs of diabetes. Sodium ions are the only ions that are partially absorbed from the renal tubules back into the blood. Tubular Secretion The last step in urine formation is tubular secretion. This is the step where the urine is made concentrated by increasing the concentration of waste elements. Thus, in this stage, substances move into the distal and collecting tubules from blood in the capillaries around these tubules. These substances are secreted by the mechanism of active transport. The substances secreted include hydrogen ions, potassium ions, ammonia, and certain drugs or metabolic end products. Thus, the kidney tubules play a crucial role in maintaining the body's acid-base balance NMT 04102 Anatomy and Physiology NTA Level 4, Semester 1
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and maintaining the electrolyte balance in the body. The distal convoluted tubules then drain the urine into the collecting tubules. Then, several collecting tubules join together to drain their contents into the collecting duct, which finally, after urine formation, flows into the ducts of Bellini. This then eventually reaches the renal pelvis, from where the urine flows into the ureter to reach the urinary bladder. Thus, these were the various urine formation steps that take place right from the time when blood flows into the kidneys, till urine is passed into the ureters. The various urinary system diseases occur when there are problems with the functioning of the kidneys, which reflects in the final urine color, odor and concentration.
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Handout 7.6: Kidneys and Ureter Blood Supply
Source: Gray’s Anatomy 2007.
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Handout 7.7: The Urinary Bladder
Source US National Cancer Institute
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Handout 7.8: The Urethra
Source: Grays Anatomy 2007.
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Source Tank, Patrick W.; Gest, Thomas R (2007)
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Session 8:
Structure and Function of the Integumentary System
Total Session Time: 120 Minutes Prerequisites None Learning Tasks By the end of this session, students are expected to be able to: Identify the organs of the Integumentary system Describe common causes of structure and physiological functions of the Integumentary system Resources Needed Flip charts, marker pens, and masking tape Black/white board and chalk/whiteboard markers Anatomical models and atlas LCD and Computer Handout 8.1: The Dermis and Hypodermis Handout 8.2: The Epidermis Handout 8.3: Layers of the Skin Handout 8.4: Skin Circulation Handout 8.5: Hair Follicle Handout 8.6 The Nail SESSION OVERVIEW Step
Time
Activity/Method
Content
1
05 Minutes
Presentation
2
25 Minutes
3
80 Minutes
4
05 Minutes
Presentation
Key Points
5
05 Minutes
Presentation
Evaluation
Presentation of Session and Learning Tasks
Presentation, Buzz Presentation, Group Discussion
Organs of the Integumentary System Structure and Physiological Functions of the Integumentary System
SESSION CONTENT Step 1: Presentation of Session Title and Learning Tasks (5 minutes) READ or ASK students to read the Learning tasks and clarify ASK students if they have any questions before proceeding
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Step 2: Organs of the Integumentary System (25 minutes) Activity: Buzzing (5 minutes) ASK the students to pair up give the meaning of integumentary system for 2 minutes ALLOW few student to responses and let other pairs to provide unmentioned responses CLARIFY and summaries by using the information below
Definition of the integumentary system o Integumentary means covering, it covers the outside of the body o Is the organ system that protects the body from damage, comprising the skin and its accessory structures. o The accessory structures are the hair, nails and glands. o The appearance of the integumentary system can indicate physiological imbalances in the body o Disorders of other parts of the body can be reflected there. Organs of the integumentary system o The principle organ of the integumentary system is the skin o Accessory organs includes The hair Nails Gland
Step 3: Structure and Physiological Functions of the Integumentary System (80 minutes) Activity: Small Group Discussion ( 30 minutes) DIVIDE students into small manageable groups ASK students to discussion in groups on structure and physiological functions of the Integumentary System 10 minutes ALLOW groups ask students to provide their response for 2 minutes each CLARIFY and summaries by using the contents below
The integumentary system has multiple roles in homeostasis. All body systems work in an interconnected manner to maintain the internal conditions essential to the function of the body. The skin has an important job of protecting the body and acts as the body’s first line of defense against infection, temperature change, and other challenges to homeostasis.
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Structure of the Intergumentary System The Dermis, Hypodermis and the Epidermis The skin rest on the hypodermis. Hypodermis is located between the dermis and underlying deep fascia Hypodermis is not a part of skin. It is also known as subcutaneous tissue. This consists of loose connective tissue with collagen and elastic fibers. The main cells in the hypodermis are the fibroblasts, adipose cells and macrophages. Approximately half of the body stored adipose tissue is in the hypodermis. Although the amount and location vary with age, sex and diet. The skin is made up of the two major tissue layers, o Dermis o Epidermis The Dermis Is divided into two layers o The deeper reticular layer, is dense irregular connective tissue, is the main layer of the dermis consisting of layers of interlacing collagen fibers. o This layer is of elastic and collagens are oriented more in some areas than others creating tension lines (cleavage lines) and wrinkle lines in the skin. o The more superficial papillary is called from projections called papillae that extend toward the epidermis. o It is less dense than reticular and sometimes called loose connective tissue, it also contain large number of blood vessels o These fibers provide skin tone and account for the strength and toughness of the skin. o The pattern of collagen fibers in a particular region determines the characteristic of the skin o The deep layer of the dermis contains hair follicles, with their associated smooth erector muscles and sebaceous glands. o Contraction of the erector muscles erects the hairs (causing goose bumps), thereby compressing the sebaceous glands and helping them secrete their oily product onto the skin. o The dermis composed of nerve endings, hair follicles, smooth muscles, glands, and lymphatic vessels The nerve ending are varied in structure and function, Free nerve endings are for pain, itch, tickle and temperature sensation Hair follicle receptors are for light touch Pacinian corpuscles are for deep pressure Meissner’s corpuscles for the ability to detect simultaneous stimulation at two points on the skin Ruffini’s end organs for touch or pressure o Skin ligaments, consisting of numerous small fibrous bands, extend through the subcutaneous tissue and attach the deep surface of the dermis to the underlying deep fascia. o The length and density of these ligaments determine the mobility of the skin over deep structures.
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The Epidermis Is a keratinized stratified (layered) epithelium with a tough outer surface composed of keratin (a fibrous protein). The epidermis is made up of several layers (strata of cells) which extends from the deepest germinative layer to the surface stratum corneum namely o Basal layer (stratum basale) o Spinous or prickle cell layer (stratum spinosum) o Granular layer (stratum granulosum), o Clear layer (stratum lucidum) o And cornified layer (stratum corneum) The outer layer of the epidermis is continuously or rubbed away with replacement of new cells from the basal layer. The cells of epidermis include, o Most of the cells are called keratinocytes because they produce protein called keratin. o Melanocytes which contribute to skin colour, o Langerhans’ cells which are part of immune system, o Merkel’s which are specialized epidermal cells associated with nerve endings responsible for detecting light touch and superficial pressure, This process renews the epidermis of the entire body every 25 to 45 days. The epidermis is avascular (no blood vessels or lymphatics) and is nourished by the vessels in the underlying dermis. The skin is supplied by afferent nerve endings that are sensitive to touch, irritation (pain), and temperature. Most nerve terminals are in the dermis, but a few penetrate the epidermis. Functions of the Intergumentary System Protection for the body from environmental effects, such as, o Abrasions, o Melanin absorb ultraviolet light and protect underlying tissue, o Skin prevent the entry of microorganisms and other harmful substances, o Prevent dehydration by reducing water loss from the body because its lipids act as barrier to the diffusion of water o Nail protect the ends of the digits from damage and can be used in defense o Hair follicles act as insulator and protect from ultraviolet light o Temperature regulation through sweat glands, blood vessels, and fat deposits, Sensation , the integumentary system has sensory receptors that can detect heat, cold, pain, touch, temperature and pressure) Synthesis and storage of vitamin D, when exposed to ultraviolet light, the skin produces a molecule that can be transformed into vitamin. D Excretion , small amount of waste products are lost through the skin and in gland secretions
Refer students to: Handout 8.1: The Dermis and Hypodermis Handout 8.2: The Epidermis Handout 8.3: Layers of the Skin
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Skin Colour, Vascular Supply and Lymphatic Drainage of the Skin Pigment in the skin, blood circulating through the skin and the thickness of the stratum corneum together determine skin colour. o Melanin is the term used to describe a group of pigment responsible for skin, hair and eye colour o Melanin provide protection against ultraviolet rays from the sun o Large amount of melanin is found in certain region of the skin, such as freckles, moles, nipples, areolae of the breast, the axilla and the genitalia o Melanin is produced by melanocytes, o Melanin production is determined by genetic factor, o Although many genes are responsible for skin colour, a single mutation can prevent the manufacture of melanin. o Albinism is usually a recessive genetic trait causing inability to produce tyrosinase the result is a deficiency or absence of pigment in the skin, hair and eyes o During pregnancy, certain hormones cause an increase in melanin production in the mother which in turn cause darkening of the nipple, areolae and genitalia o Exposure to ultraviolet light darkens melanin already present and stimulate production resulting in tanning of the skin Vascular Supply and Lymphatic Drainage of the Skin The metabolic demands of the skin are not great, and yet, under normal conditions, its blood flow exceeds nutritional requirements by 10 times, and may amount to 5% of the cardiac output. This is because the cutaneous circulation has an important thermoregulatory function, and is arranged so that its capacity can be increased or decreased rapidly by as much as 20 times, in response to the required loss or conservation of heat. The blood supply to the skin originates from three main sources, the direct cutaneous system, the musculocutaneous system and the fasciocutaneous system. o The direct cutaneous system of vessels is derived from the main arterial trunks and accompanying veins. o Vessels course in the subcutaneous fat parallel to the skin surface, and are confined to certain areas of the body, e.g. the supraorbital artery, the superficial circumflex iliac artery and the dorsalis pedis artery. o The musculocutaneous perforators arise from the intramuscular vasculature, pass through the surface of the muscle, and pierce the deep fascia to reach the skin by spreading out in the subcutaneous tissues. o The fasciocutaneous system consists of perforating branches from deeply located vessels (deep to the deep fascia) which pass along intermuscular septa and then fan out at the level of the deep fascia to reach the skin. Examples include the fasciocutaneous perforating vessels from the radial and ulnar arteries Refer students to Handout 8.4: Skin Circulation Types and Structure of Hair The presence of hair is one of the characteristic of mammals. o If hair is dense and covers the most of the body surface is called fur. o In human, hair is found everywhere on the skin except the palm, soles, lips, nipples, parts of the external genitalia, and distal segments of the fingers and toes. NMT 04102 Anatomy and Physiology NTA Level 4, Semester 1
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By the fifth or sixth month of foetal development, delicate unpigmented hair called lanugo develops and covers the foetus. Near the time of birth, terminal hair, which are short, fine, and usually unpigmented replace lanugo of the scalp, eyelids and eye brow Vellus hairs which are short, fine and usually unpigmented replace the lanugo of the rest of the body. At puberty terminal hair of the pubic and axillary region replace much of the vellus hair. The hair of the chest, legs and arms is approximately 90% terminal hair in male compared to 35% in female. In male terminal hair replace the vellus hair of the face to form beard A hair is divided into o Shaft , protrude above the surface of the skin o The root is located below the surface. o The root is expanded to form the hair bulb. Most of the root and the shaft of the hair are composed of columns of dead keratinized epithelial cells arranged in three concentric layers Medulla – is the central axis of the hair consists of the two or three layers of the cells containing soft keratin, The cortex – forms the bulk of the hair consisting of the cells containing hard keratin, The cuticle is a single layer of cells that forms hair surface, The hair follicle consists of:o Dermal root sheath, is the portion of the dermis that surrounds the epithelial root sheath o Epithelial root sheath, is divided into external and internal part o The hair bulb is an expanded knob at the base of the hair root. o Inside the hair bulb is a mass of undifferentiated epithelial cells, the matrix, which produced the hair and the internal epithelial root sheath. Hair growth is produced in cycles that involve a growth stage and a resting stage. o During the growth stage hair is formed by cells of the matrix that differentiate, become keratinized and die. o The hair grows longer as cells are added at the base of the hair root. o Eventually hair growth stops; hair follicle shortens and holds the hair in place. o A resting period follows after which a new cycle begins and a new hair replace the old hair, which falls out of the hair follicle o The most common permanent hair loss is pattern baldness. o Hair follicles are lost and the remaining hair follicles revert to producing vellus hair. This kind of hair loss is common in men, can also occur in women. o Genetic factors and hormones testosterone are involved in causing pattern baldness Hair colour, melanin is produced by melanocytes within the hair bulb matrix and passed to keratinocytes in the hair cortex and medulla. With age the amount of melanin in hair can decrease, causing the colour of the hair to fade or become white hairs Associated with each hair follicle are smooth muscle cells, the arrector pili that extend from the dermal root sheath of the follicle to the papillary layer of the dermis. Refer Students to Handout 8.5: Hair Follicle
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The Glands and a Nail The major glands of the skin are, o Sebaceous gland o Sweat glands Sebaceous glands are located in the dermis, are simple or compound alveolar glands that produce sebum, an oily, white substance rich in lipids. Sebum is released by the lysis and death of secretory cells, so they are classified as holocrine glands. Most sebaceous gland is connected by duct to the upper part of the hair follicle from which sebum oils the hair and the skin surface. o Sebum prevents drying and provides protection against some bacteria. o Few sebaceous glands are located in the lips, in the eyelids (meibomian glands) and in the genitalia are not associated with hairs but open direct on the surface. Sweat glands are of two types o Merocrine sweat glands are the most common type of sweat gland. o They are simple coiled tubular glands that open directly onto the surface of the skin through sweat pores. o The coiled part produce an isotonic fluid that is mostly water but also contains some salts like sodium chloride, small amount of ammonia, urea, uric acid and lactic acid o As this fluid moves through the duct, sodium chloride moves by active transport from the duct back into the body, thereby conserving salts. When the body temperature starts to rise above normal levels, the sweat glands produce sweat, which evaporates and cool the body. Merocrine gland are more numerous in the palms of the hands and soles of the feet, but absent from the margin of the lips, labia minora, and tips of the penis and clitoris o Apocrine sweat glands are compound coiled tubular glands that usually open into hair follicles superficial to the opening into hair follicles superficial to the opening of the sebaceous glands. They are found in the axilla and genitalia (scrotum and labia majora) and around the anus and do not help to regulate temperature. They become active at puberty as a result of the influence of sex hormones. Their secretion contain organic substance the 3-methyl-2-hexenoic acid, that are essentially odourless when first released but quickly metabolized by bacteria to cause what is known body odour. o Other glands include Ceruminous glands are modified merocrine glands located in the ear canal (external auditory meatus) produce cerumen (earwax) Mammary glands these are modified apocrine sweat glands located in the breast. They produce milk. This has been discussed in detail in the session of accessory organs of female reproductive system. Nail A nail is a horn-like envelop covering the dorsal aspect of the terminal phalanges of fingers and toes The parts of the nail are, o Matrix, the only living part of the nail. o It is situated behind and underneath the nail fold and produces the keratin which makes up the nail plate. o If the matrix is damaged, growth of the nail plate is affected. NMT 04102 Anatomy and Physiology NTA Level 4, Semester 1
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o o o o o o o o o o o o o o o o
Eponychium, Dead skin that forms around the cuticle area. It can be lifted and trimmed during a professional manicure treatment. Tends to be more prominent on males. Paronychium, The 'live' skin that folds around the cuticle area, giving protection to the matrix. Hyponychium, The area of attachment between the nail plate and nail bed that lies underneath the free edge. Anatomical terms of location: proximal and distal, end of the nail. Nail plate, the hard and translucent part of the nail composed of layers of keratin. Nail bed, Tissue underneath the nail plate, responsible for the pink colour of the nail. It also determines what shape the nail will grow. It is informally referred to as "the quick", especially the end nearest the fingertip. Lunula, The visible part of the matrix, a whitish crescent shape around the base of the nail plate. Tends to only be visible in larger nails. Nail fold, A fold of hard skin overlapping the base and sides of a fingernail or toenail Free edge or distal edge, the part of the nail that extends past the finger, beyond the nail plate. There should always be a free edge present to prevent infections. Nail groove, Grooves that guide the direction of nail growth. They are located down the sides of the nail fold.
Function of the Nail Nails act as a counterforce when the end of the finger touches an object, thereby enhancing the sensitivity of the fingertip, even though there are no nerve endings in the nail itself. Actual growth rate is dependent upon age, gender, season, exercise level, diet, and hereditary factors. Refer Students to Handout 8.6: The Nail
Step 4: Key Points (5 minutes)
The integumentary system consists of the skin and the accessory structures such as hair, nails and glands. The main functions of the skin includes: - protection; Body temperature regulation; formation and storage of vitamin D; Absorption and excretion of substances The major glands of the skin are the sebaceous gland and sweat glands A nail is a horn-like envelop covering the dorsal aspect of the terminal phalanges of fingers and toes
Step 5: Evaluation (5minutes)
What are the functions of skin? Mention the layers of the skin Mention parties of the nail
ASK students if they have any comments or need clarification on any points
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References
Seeley, R. R., Stephens, T. D. & Tate, P. (2003). Anatomy and Physiology. New York: McGraw-Hill Standring, S. (2008). Grays’s Anatomy The anatomical basis of clinical practice. United Kingdom: Churchill Livingstone Elservier Thibodeau, G. A., Patton, K. T. (1999). Anatomy & Physiology. Saint Louis: Mosby, Von Hoffman Press, Inc Waugh, A. & Grant, A. (2006). Ross and Willson Anatomy and physiology in Health and illness. United Kingdom: Churchill Livingstone Elservier.
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Handout 8.1: The dermis and hypodermis
Source: standring 2005 .
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Handout 8.2: The epidermis
Source: standring 2005.
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Handout 8.3: Layers of the skin
Source: standring 2005.
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Handout 8.4: Skin circulation
Source: standring 2005.
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Handout 8.5: Hair Follicle
Source: standring 2005.
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Handout 8.6: The Nail
Source: standring 2005.
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Session 9:
Structure and Function of Female Reproductive System
Total Session Time: 120 Minutes Prerequisites None Learning Tasks By the end of this session, students are expected to be able to: Indentify the organs of the female reproductive system Describe the structure and physiological functions of the female reproductive system Resources Needed Flipcharts, Marker pens, and Masking tape Black/white board and chalk/whiteboard markers Anatomical models and atlas LCD and Computer Handout 9.1: The Female External Genitalia Handout 9.2: Ovarian Ligaments Handout 9.3: Ovarian Blood Supply Handout 9.4: Hormonal Role and Puberty in Females SESSION OVERVIEW Step
Time
Activity/Method
Content
1
05 Minutes
Presentation
2
35Minutes
3
70 Minutes
4
05 Minutes
Presentation
Key Points
5
05 Minutes
Presentation
Evaluation
Presentation of the Session and Learning Tasks
Presentation, Buzz Presentation, Group Discussion
Organs of the Female Reproductive System Structure and Physiological Functions of the Female Reproductive System
SESSION CONTENT Step 1: Presentation of Session Title and Learning Tasks (5 minutes) READ or ASK students to read the learning tasks and clarify ASK students if they have any questions before proceeding
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Step 2: Organs of the Female Reproductive System (35minutes) Activity: Buzzing (5 minutes) ASK the students to pair up and mention organs which make up the female reproductive system five minutes ALLOW few student to responses and let other pairs to provide unmentioned responses CLARIFY and summaries by using the information below
Without the reproductive system, the human species could not survive. The female reproductive system produces oocytes and can receive sperm cells, which one of them may unite with an oocyte (female gamete) to form the first cell of an offspring It is also involved in nurturing the development of a new individual until birth and usually for some considerable time after birth i.e. it provide protection and nutrition to the developing offspring for up to several years after conception. Female and male reproductive system all are derived from the same embryologic structures In human being, essence of sexual reproduction is that each offspring has parents and a combination of genes from both.
The Organs of the Female Reproductive System Primary organs : the ovaries (gonads), which produce ova (gametes) which are also internal organs Accessory organs o External genitalia – the vulva (Labia majora, labia minora, Clitoris, Hymen, and vestibular glands) o Internal genitalia – uterine tubes, uterus and vagina o Additional sex glands such as the mammary gland o Primary organ for female reproductive system (the ovary) has the main functions of: Production of female gametes or oocytes Secretion of female sex hormones including oestrogen and progesterone
Step 3: Structure and Physiological Functions of the Female Reproductive System (70 minutes) Activity: Small Group Discussion ( 30 minutes) DIVIDE students into small manageable groups ASK students to discussion in groups on structure and physiological functions of the Integumentary System 10 minutes ALLOW groups ask students to provide their response for 2 minutes each CLARIFY and summaries by using the contents below NMT 04102 Anatomy and Physiology NTA Level 4, Semester 1
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The External Genitalia (Vulva) Female external genital organ is known as the vulva. This consists of the following structures: o Perineum is the skin-covered muscular region between the vaginal orifice and the anus It is a roughly diamond shaped area between the thighs; extend from the symphysis pubis interiorly to the coccyx posteriorly. The perineum has great clinical importance because of the danger of being torn during childbirth. Such tears are often deep, have irregular edges, to avoid these tears sometime is necessary to do a surgical incision known as episiotomy during childbirth if there is a threat for tear to occur o The Mons pubis is the rounded fatty eminence anterior to the pubic symphysis, pubic tubercle, and superior pubic rami. o After puberty, the Mons pubis is covered with coarse pubic hairs. o The labia majora are prominent folds of skin that bound the pudendal cleft, the slit between the labia majora and indirectly provide protection for the urethral and vaginal orifices o The labia minora are folds of fat-free, hairless skin. o They have a core of spongy connective tissue containing erectile tissue and many small blood vessels. o Internal surface of each labium minus consists of thin moist skin; it has the typical pink color of a mucous membrane and contains many sensory nerve endings. o The labia minora are enclosed in the pudendal cleft within the labia majora and surround the vestibule into which the external urethral and vaginal orifices open o The clitoris is an erectile organ located where the labia minora meet anteriorly. o The clitoris consists of a root and a body, which are composed of two crura, two corpora cavernosa, and the glans of the clitoris. o The glans is covered by the prepuce of the clitoris. o The clitoris is highly sensitive and enlarges on tactile stimulation. o The glans is the most highly innervated part of the clitoris. o It is engorges with blood during sexual arousal and derived from the same embryonic structures as penis in males o The vestibule is the space surrounded by the labia minora, which contains the openings of the urethra, vagina, and ducts of the greater and lesser vestibular glands o Urinary meatus is the small opening of the urethra, situated between the clitoris and vaginal orifice. o On each side of the external urethral orifice are the openings of the ducts of the paraurethral glands. o Vaginal orifice is an opening that s larger than the urinary meatus. It is located posterior to the meatus. o The size and appearance of the vaginal orifice vary with the condition of the hymen, a thin fold of mucous membrane within the vaginal orifice surrounding the lumen. o After its rupture, only remnants of the hymen, hymenal caruncles (tags) are visible o The bulbs of the vestibule are paired masses of elongated erectile tissue that lie along the sides of the vaginal orifice under cover of the bulbospongiosus muscles. o The bulbs are homologous with the bulb of the penis and the corpus spongiosum. o The greater vestibular glands (Bartholin glands) are located on each side of the vestibule, posterolateral to the vaginal orifice. o These glands are round or oval and are partly overlapped posteriorly by the bulbs of NMT 04102 Anatomy and Physiology NTA Level 4, Semester 1
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o o o o
the vestibule, and both are partially surrounded by the bulbospongiosus muscles. The slender ducts of these glands pass deep to the bulbs and open into the vestibule on each side of the vaginal orifice. These glands secrete mucus into the vestibule during sexual arousal. The lesser vestibular glands are smaller glands on each side of the vestibule that open into it between the urethral and the vaginal orifices. These glands secrete mucus into the vestibule, which moistens the labia and vestibule.
Functions of the Vulva Cover the deeper structures of the female perineum Labia’s maintain the closure of the vaginal introitus Integument of the vulva has specialized nerve ending Secrete mucous that maintain the epithelial moisture of the vagina Blood and Nerve Supply of the Vulva The arterial supply to the vulva is from the external and internal pudendal arteries. The internal pudendal artery supplies most of the skin, external genitalia, and perineal muscles. The labial arteries are branches of the internal pudendal artery, as are those of the clitoris. The labial veins are tributaries of the internal pudendal veins and accompanying veins. (venae comitantes). Venous engorgement during the excitement phase of the sexual response causes an increase in the size and consistency of the clitoris and the bulbs of the vestibule. As a result the clitoris becomes turgid. The vulva contains a rich network of lymphatic vessels that pass laterally to the superficial inguinal lymph nodes. The glans of the clitoris and anterior labia minora may also drain to the deep inguinal nodes or internal iliac nodes. The anterior aspect of the vulva is supplied by anterior labial nerves, derived from the ilioinguinal nerve and the genital branch of the genitofemoral nerve. The posterior aspect is supplied by the perineal branch of the posterior cutaneous nerve of the thigh laterally and the pudendal nerve centrally. The pudendal nerve is the main nerve of the perineum. Its posterior labial nerves supply the labia; deep and muscular branches supply the orifice of the vagina and superficial perineal muscles; and the dorsal nerve of the clitoris supplies deep perineal muscles and sensation to the clitoris. The bulb of the vestibule and erectile bodies of the clitoris receive parasympathetic fibers via cavernous nerves from the uterovaginal plexus. Parasympathetic stimulation produces increased vaginal secretion, erection of the clitoris, and engorgement of erectile tissue in the bulbs of the vestibule. Refer Students to Handout 9.1: The Female External Genitalia The Internal Genitalia Ovaries o Ovaries are oval shaped small organs measuring approximately 3 cm x 1.5 cm o The ovary is located in the lateral wall of the pelvis in a region called the ovarian fossa NMT 04102 Anatomy and Physiology NTA Level 4, Semester 1
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o The ovaries develop high on the posterior abdominal wall and then descend before birth, bringing with them their vessels, lymphatic’s, and nerves. o Unlike the testes, the ovaries do not migrate through the inguinal canal into the perineum, but stop short and assume a position on the lateral wall of the pelvic cavity o Ovaries are located near the attachment of the broad ligament to the lateral pelvic walls, suspended from both by peritoneal folds, the mesovarium from the posterosuperior aspect of the broad ligament and the suspensory ligament of the ovary from the pelvic wall. o The ovary also attaches to the uterus by the ligament of ovary, which runs within the mesovarium. Structure of Ovary and Formation of Primordial Follicles The ovaries have two layers of tissues, the medulla and the cortex. o The medulla lies in the centre and consists of fibrous tissue, blood vessels and nerves. o The cortex surrounds the medulla. o It has connective tissue or stroma covered by germinal epithelium. o It contains ovarian follicles in various stages of maturity Ovum production or oogenesis begins before a woman’s birth, accelerates at puberty and ends at menopause. Between puberty and menopause oogenesis occurs on a monthly basis as part of the ovarian cycle. The stem cells of female complete their mitotic division before birth. Between the third and seventh months of fetal development The primary oocytes remain in a state of suspended development until the individual reaches puberty, when rising levels of FSH trigger the start of the ovarian cycle. Primary oocyte and its follicle cells form a primordial follicle. Not all primary oocytes produced during developmental survive until puberty. The ovaries have roughly 2 million primordial follicles at birth, by at time of puberty the number has dropped to about 400,000, the rest of the primordial follicles degenerates in a process called atresia Functions of the Ovaries Produces female gametes or ova Secretes female sex hormones (estrogen and progesterone) Regulate reproductive functions in the female Blood Supply, Lymph Drainage and Nerve Supply Arterial supply - The ovarian arteries arise from the abdominal aorta just below the renal arteries and descend along the posterior abdominal wall Venous drainage - The right ovarian vein opens into the inferior vena cava and the left into the left renal vein Lymph drainage – this is by lateral aortic and preaortic lymph node Nerve supply – By the parasympathetic nerve from the sacral out flow
Refer Students to: Handout 7.2: Ovarian Ligaments Handout 7.3: Ovarian Blood Supply
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Fallopian Tubes Are about 10 cm long and extends from the sides of the uterus between the body and fundus The end of each tube has finger like projection called fimbriae Structure Have an outer covering of peritoneum ( broad ligament), a middle layer of smooth muscle and aligned with ciliated epithelium Blood Supply, Lymph Drainage, and Nerve Supply Arterial supply – by uterine arteries, branch of the internal uterine arteries Venous drainage – By uterine veins, branch of the internal uterine veins, Lymph drainage – by deep and superficial lymph vessels Nerve Supply – Consists of the parasympathetic fibers from the sacral outflow and sympathetic fibers from the lumbar outflow Functions Moves the ovum from the ovary to the uterus by peristalsis and ciliary movement Produces mucous that aid in movement of the ovum and protozoa Enables fertilization to take place in the area Uterus Is hallow muscular pear shaped organ, flattened antero posteriorly Lies in the pelvic cavity between the urinary bladder and the rectum Mostly lies in a position of anteflection anteversion Measures about 7.5 cm long, 5 cm wide, 2.5 cm thick Weighs approximately 30 – 40 gm Parts of the Uterus Fundus – A doom shaped part of the uterus above the opening of the uterine tubes Body – Is the main part is narrowest inferiorly at the internal os where it is continuous to the cervix Cervix – (Neck of the Uterus) Protrudes through the anterior wall of the vagina opening to it at the external os Structure Composed of three layers of tissue; Perimetrium, Myometrium and Endometrium o Perimetrium Is the outer layer, distributed differently in the various surfaces of the uterus o Myometrium Is the middle muscular layer interlaced with areola tissue, blood vessels and nerves o Endometrium Is the inner layer consist of columnar epithelium containing a large number of mucous secreting tubular glands Blood Supply, Lymph Drainage, and Nerve Supply Arterial supply – by uterine arteries, branch of the internal uterine arteries Venous drainage – By uterine veins, branch of the internal uterine veins, NMT 04102 Anatomy and Physiology NTA Level 4, Semester 1
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Lymph drainage – by deep and superficial lymph vessels Nerve Supply – Consists of the parasympathetic fibers from the sacral outflow and sympathetic fibers from the lumbar outflow
Supporting Structures The uterus is supported in the pelvis by surround ding organs, muscles of the pelvic floor and the following ligaments to that suspend it from the wall of the pelvis o Broad ligaments Uterosacral ligaments Transverse cervical ligaments Pubocervical fascia Functions of the Uterus Serves to receive the sperm in mares Allow passage of sperm from site of deposition to uterine tubes for fertilization Provides suitable environment for o Implantation of the embryo o Nourishment of the embryo and fetus during pregnancy Provides mechanical protection of the fetus Expels the mature fetus at the end of pregnancy Plays role in menstruation if pregnancy do not occur The Vagina The vagina is a fibromuscular tube lined with stratified squamous epithelium, connecting the external and internal organs of reproduction. It runs obliquely upwards and backwards at an angle of about 45 between the bladder in front and rectum and anus behind. Structure of the Vagina The vagina has three layers o The outer covering of areolar tissue. o The middle layer of smooth muscle. o The inner layer of stratified squamous epithelium that forms ridges of rugae o Between puberty and the menopause, lactobacillus acidophilus bacteria are normally present, which secrete lactic acid, maintaining the Ph between 4.9 and 3.5. o The acidity inhibits the growth of most other microbes that may enter the vagina from the perineum. Functions Acts as a receptacle for the penis during coitus During sexual intercourse, the lining of the vagina lubricates and stimulates the glans penis, which in turn triggers the ejaculation of semen Provides an elastic passageway through which the fetus and placenta passes during child birth Provide a path for menstrual fluid to leave the body
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Blood Supply, Lymph Drainage and Nerve Supply Arterial supply. o An arterial plexus is formed round the vagina, derived from uterine and vaginal arteries, which are branches of the internal iliac arteries. Venous drainage. o A venous plexus situated in the muscular wall drains into the internal iliac veins. Lymph drainage. o This is through the deep and superficial iliac glands. Nerve supply. o This consists of parasympathetic fibers from the sacral outflow, sympathetic fibers from the lumbar outflow and somatic sensory fibers from the pudendal nerves.
Step 4: Key Points (5 minutes)
Primary organ for female reproductive system is the ovary whose main functions are production of female gametes or oocytes and secretion of female sex hormones including oestrogen and progesterone The perineum has great clinical importance because of the danger of being torn during childbirth Maturation of the follicle is stimulated by follicle stimulating hormone (FSH) from the anterior pituitary, and oestrogen secreted by the follicle lining cells.
Step 5: Evaluation (5minutes)
Describe structure of the vulva Describe the blood supply of the ovary Mention ligaments of the ovary Name 5 features of female puberty
ASK students if they have any comments or need clarification on any points
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References
Elsevier, Drake et el: Gray’s Anatomy for students-www.studentsconsult.com. Retrieved on 15th November, 2011 Seeley, R. R., Stephens, T. D. & Tate, P. (2003). Anatomy and Physiology. New York: McGraw-Hill Thibodeau, G. A., Patton, K. T. (1999). Anatomy & Physiology. Saint Louis: Mosby, Von Hoffman Press, Inc Waugh, A. & Grant, A. (2006). Ross and Willson Anatomy and physiology in Health and illness. United Kingdom: Churchill Livingstone Elservier.
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Handout 9.1: The female external genitalia
Source: www.studentsconsult.com
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Handout 9.2: Ovarian ligaments
Source: www.studentconsult.com
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Handout 9.3: Ovarian blood supply
Source: www.studentconsult.com
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Handout 9.4: Hormonal Role and Puberty in Females
Maturation of the follicle is stimulated by follicle stimulating hormone (FSH) from the anterior pituitary, and oestrogen secreted by the follicle lining cells. Ovulation is triggered by a surge of luteinizing hormone (LH) from the anterior pituitary, which occurs a few hours before ovulation. After ovulation, the follicle lining cells develop into the corpus luteum (yellow body), under the influence of LH from the anterior pituitary. The corpus luteum produces the hormone progesterone and some oestrogen. If the ovum is fertilized it embeds itself in the wall of the uterus where it grows and develops and produces the hormone human chorionic gonadotrophin (hCG), which stimulates the corpus luteum to continue secreting progesterone and oestrogen for the first 3 months of the pregnancy, after which time this function is continued by the placenta. If the ovum is not fertilized the corpus luteum degenerates and a new cycle begins with menstruation. At the site of the degenerated corpus luteum an inactive mass of fibrous tissue forms, called the corpus albicans. Sometimes more than one follicle matures at a time, releasing two or more ova in the same cycle. When this happens and the ova are fertilized the result is a multiple pregnancy.
Facts An average cycle lasts approximately 28 days, but every woman's cycle is different. You should not be alarmed if your cycle is shorter or longer. By monitoring or even charting your cycles, you can learn what is normal for your body and be able to identify any abnormalities that could indicate health problems. Psychological stress can delay ovulation and result in a longer cycle. Many people mistakenly believe that worrying about a late period can delay it even further; however, once ovulation occurs, the duration of the luteal phase varies little from cycle to cycle. Extreme changes in weight or excessive exercise can cause amenorrhea, an absence of periods that is usually temporary
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Session 10: Structure and Function of the Female Breast and the Menstrual Cycle Total Session Time: 120 Minutes Prerequisites None Learning Tasks By the end of this session, students are expected to be able to: Describe the structure and functions of the female breast Describe the physiology of the menstrual cycle Resources Needed Flipcharts, Marker pens and Masking tape Black/white board and chalk/whiteboard markers Anatomical charts Anatomical models and atlas LCD and Computer Handout 10.1 Handout 10.2 SESSION OVERVIEW Step
Time
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Presentation of Session Title and Learning Tasks
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35 Minutes
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Presentation, Brainstorm Presentation, Group Discussion
Structure and Functions of the Female Breast Physiology of the Menstrual Cycle
SESSION CONTENT Step 1: Presentation of Session Title and Learning Tasks (5 Minutes) READ or ASK students to read the Leaning tasks and clarify ASK students if they have any questions before proceeding
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Step 2: The Female Breast (35 minutes) Activity: Brainstorming (05 minutes) ASK the student to brain storm the structure of the breast for 2 minutes ALLOW few students to responses and let other pairs to provide unmentioned responses WRITE their response on the flip chart/board CLARIFY and summaries by using the information below The Breast or Mammary Gland These are 2 accessory organs of the female reproductive system Organs of milk production During childhood breasts are small and immature until puberty Grow and develop under the influence of estrogen and progesterone Structure Consist of granular tissue, fibrous tissue and fatty tissue Each breast contains about 20 lobe The lobules consists of a cluster of alveoli that opens into small ducts, and this unite to form large excretory ducts, called lactiferous duct From lactiferous duct there are small duct which opens on to the surface at the nipple o The nipple Is a small projection at the center of the breast surrounded by a pigmented area, the areola On the surface of the areola there are numerous number of sebaceous glands (montgomerous tubercles) that rubricate the nipple during lactation Refer Handout 10.1: Structure of the Breast Blood Supply, Lymph Drainage and Nerve Supply Arterial supply o Is from the thoracic branches of the axillary arteries and from the internal mammary and intercoastal arteries Venous drainage o If formed by anastomotic circle round the base of the nipple from which branches carry the venous blood to the circumference and end in the axillary and mammary veins Lymph drainage o Is mainly into the superficial axillary lymph vessels and nodes Nerve supply o Supplied by branches from the 4th, 5th, and 6th thoracic nerves which contains sympathetic fibers
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Functions of the Breast Production of milk for lactation Sebaceous glands rubricate the nipple during breast feeding Adipose tissue provides the bulk of the breast The nipple help the infant to suck the milk from the breast
Step 3: Physiology of the Menstruation Cycle (70 minutes) Activity: Small Group Discussion ( 30 minutes) DIVIDE students into small manageable groups ASK students to discussion in groups on physiological changes during puberty in females (development of secondary sex characteristics) for 10 minutes ALLOW groups ask students to provide their response for 2 minutes each CLARIFY and summaries by using the contents below Puberty in Females Puberty is the age at which the internal reproductive organs reach maturity. This is called the menarche, and marks the beginning of the childbearing period. The ovaries are stimulated by the gonadotrophins from the anterior pituitary, follicle stimulating hormone and luteinizing hormone. The age of puberty varies between 10 and 14 years, and the number of physiological and psychological changes takes place at this time(development of secondary sex characteristics): o Uterus, uterine tube and the ovaries reach maturity o The menstruation cycle and ovulation begins o The breasts develop and enlarge. o Pubic and Axillary hairs begin to grow. o Increase in height and widening of the pelvis o Increase in fat deposited in subcutaneous tissue especially in the hips and breasts The Menstrual Cycle The four phases of the menstrual cycle are the follicular phase, ovulation, the leuteal phase and menstruation Follicular phase o A cycle begins with the first day of the period. o In the days leading up to the period, the body is preparing for a possible pregnancy by building up a think lining on the wall of the uterus, which will provide nourishment to an implanted fertilized egg. o A follicle stimulating hormone (FSH) is released by the pituitary gland, causing follicles in the ovaries to begin maturing and begin releasing estrogen, another hormone that helps develop the uterine lining. o As the estrogen levels increase, one may experience symptoms associated with premenstrual syndrome (PMS), such as mood swings and headaches. Ovulation o After approximately two weeks, one of the follicles will release an egg, which will NMT 04102 Anatomy and Physiology NTA Level 4, Semester 1
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travel from the ovary into the fallopian tube. o A woman may release two or more eggs within a 24-hour period. o This process of releasing an egg or ovulation is generally believed to occur around day 14 of the cycle, but the actual date can vary greatly from woman to woman. o It is at this point in her cycle that a woman is fertile, or capable of becoming pregnant. o After ovulation, the ruptured follicle will begin releasing the hormone progesterone, which prevents any other eggs from being released. Luteal Phase o The period between ovulation and menstruation is known as the luteal phase. o During this phase, the ruptured follicle, or the corpus luteum, will continue to release progesterone, which will continue to thicken and build the uterine lining. o The luteal phase typically lasts between 12 and 16 days. If fertilization does not occur, the corpus luteum will begin to degenerate, causing the uterine lining to disintegrate. Menstruation o As the uterine lining begins to disintegrate, the resulting blood and tissue is shed through the vagina. o All menstrual period typically lasts from three to seven days and consist of about 2 1/2 oz. of fluid. o In addition to blood, menstrual fluid is made up of endometrial cells and cervical fluid. It can range in color from bright red or pink to dark brown or even blackish Refer Handout 10.2: The Menstrual Cycle
Step 4: Key Points (5 minutes)
The breast is an accessory reproductive organ of the female reproductive system responsible for milk secretion Puberty is the age at which the internal reproductive organs reach maturity. The age of puberty varies between 10 and 14 years, at which secondary sex characteristics develop Menstruation is a periodic shading of the Endometrium which occur monthly in a woman during reproductive age Menstruation occur in four phases that is Follicular phase, Ovulation, Luteal Phase, and Menstruation During ovulation the woman is fertile and capable of becoming pregnant
Step 5: Evaluation (5 minutes)
What are functions of the breast Mention the secondary sex characteristics which occur in female Explain the phases of menstruation
ASK students if they have any comments or need clarification on any points
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References
Elsevier. Drake et el: Gray’s Anatomy for students-www.studentsconsult.com. Retrived on 15th November, 2011 Roby, P. (1993). Anatomy and physiology. (6th ed.). USA: Pearson Custom. Seeley, R. R., Stephens, T. D. & Tate, P. (2003). Anatomy and Physiology. New York: McGraw-Hill Thibodeau, G. A., Patton, K. T. (1999). Anatomy & Physiology. Saint Louis: Mosby, Von Hoffman Press, Inc Waugh, A. & Grant, A. (2006). Ross and Willson Anatomy and physiology in Health and illness. United Kingdom: Churchill Livingstone Elservier.
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Handout 10.1: Structure of the Breast
Source: www.studentsconsult.com
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Handout 10.2: The Menstrual Cycle
Source: www.studentsconsult.com
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Session 11: Structure and Functions of the Male Reproductive System Total Session Time: 120 Minutes Prerequisites None Learning Tasks By the end of this session, students are expected to be able to: Identify the organs of the male reproductive systems system Describe the structure and functions of the male reproductive system Resources Needed Flipcharts, Marker pens and Masking tape Black/white board and chalk/whiteboard markers Anatomical charts Anatomical models and atlas LCD and Computer Handout 11.1: Structure of the Male Reproductive System Handout 11.2: Structure of Testes Handout 11.3: Seminiferous Tubule Cross Section SESSION OVERVIEW Step
Time
Activity/Method
Content
1
05 Minutes
Presentation
2
30 Minutes
3
75 Minutes
4
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Key Points
5
05 Minutes
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Evaluation
Presentation of Session and Learning Tasks
Presentation, Brainstorm Presentation, Group Discussion
Organs of the Male Reproductive System Structure and Functions of the Male Reproductive System
SESSION CONTENT Step 1: Presentation of Session Title and Learning Tasks (5 minutes) READ or ASK students to read the Learning tasks and clarify ASK students if they have any questions before proceeding
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Step 2: Organs of the Male Reproductive System (30 minutes) Activity: Brainstorming (05 minutes) ASK the student to brainstorm for two minutes the organs of the male reproductive system ALLOW few students to responses and let other pairs to provide unmentioned responses WRITE their response on the flip chart/board CLARIFY and summaries by using the information below
The male reproductive system consists of those organs whose function is to produce a new individual. It consists of organs whose function are to produce, transfer and ultimately introduce the mature sperm into the female reproductive tract, where fertilization can occur Primary organs for the production of gametes (spermatozoa) is the gonads i.e. testes Accessory organs that play some type of supportive process these include: o Genital ducts which convey sperm to the outside of the body these include epididymis, paired vasa deferentia, pair of ejaculatory ducts and the urethra o Accessory glands which produce secretions that nourish transport, and mature sperm. The glands are a pair of seminal vesicles, one prostate and a pair of bulbourethral (cowper’s) glands o Supportive structure – scrotum, a pair of spermatic cords and penis The male gametes are called spermatozoa
Male Reproductive System Organs Testes Epididymis gland Vas deferens Seminal vesicles Prostate gland Urethra Penis Refer Students to Handout 11.1: Structure of the Male Reproductive System
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Step 3: Structure and Functions of Male Reproductive System (75 minutes) Activity: Small Group Discussion ( 30 minutes) DIVIDE students into small manageable groups ASK students to discussion in groups on structure and functions of male reproductive system 10 minutes ALLOW groups ask students to provide their response for 2 minutes each CLARIFY and summaries by using the contents below Testes There is one pair of testes lying one in each scrotal sac. The scrotum is a bag of skin having two separate compartments. One for each testis lying at the root of the penis. Each testis is oval shaped measures. 5 x 3 x 2 cm and weighs about 15gm. The three layers of tissue that covers the testes are: o The tunica vaginalis is a double membrane forming the outer covering of the testes. This is a down growth of the abdominal and pelvic peritoneum o The tunica albuginea , this is a dense fibrous covering beneath the tunica vaginalis that surrounds the testes and then enters the gland sending out partitions (septa) that radiate through its interior dividing it into 200 or more cone-shaped lobules o The tunica vasculosa , this consists of a network of capillaries supported by delicate connective tissue The seminiferous tubules are concerned with process of spermatogenesis. The interstitial cells called Leydig cells lie between the tubules and secrete the testosterone (male sex hormone). From the lining of these tubules spermatozoa are produced by the process of cell division. Blood and lymph vessels pass to the testes in the spermatic cord. Testes are located outside the body. This is to provide favourable temperature (below the normal body temp) for spermatogenesis. The Epididymis Is a very fine convoluted tube, 4 – 6 meters long and joins the posterior part of the testes and vas deferens. It stores the spermatozoa. The spermatozoa remain inactive in epididymis and are capable of surviving for months Vas deferens Is a fibro – elastic duct 30 – 40 cm in length and extends from epididymis to end in ejaculatory duct which is joined by seminal duct and opens in prostatic urethra. The Prostate Gland Lies at the base of the urinary bladder and is covered with fibrous capsule which by a number of septa divides into many follicles. NMT 04102 Anatomy and Physiology NTA Level 4, Semester 1
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The Ejaculatory Ducts Lead from the seminal vesicle through the prostate gland to the urethra. In males the urethra is about 20 – 22 cm in length and serves the purpose of urination as well as ejaculation of semen. Functions of the Testes They produce and mature the male reproductive cells called spermatozoa Secrete seminal fluid. Secrete hormone testosterone directly into the blood. Functions of Hormone Androgen: o Maintains spermatogenesis and sexual activity Testosterone o Stimulates the development of the secondary sexual characteristics of the male such as: The growth of beard. The deepening of the voice. The growth and the distribution of hair on the body. The growth and development of the accessory sex organs. Stimulate the production of sperms at puberty Refer Students to Handout 11.2: Structure of Testes Process of Sperm Cell Development Before puberty, the testes remain relatively simple and unchanged from the time of their initial development. The interstitial cells are not prominent during this period. The seminiferous tubules contain two types of cells. o Sustentacular or sertoli cells They nourish the germ cells and produce hormones such as androgen, oestrogens and inhibins Tight junctions between the cells form a blood –testes barrier, which isolates the sperm cells from the immune system. This is important because as the sperm cells develop, they form surface antigens that could stimulate an immune response, resulting in their destruction o Germ cells Sperm cells are derived from these cells They are arranged in such a way that the most immature cells are at the periphery and most mature cells are near the lumen of the seminiferous tubule. The most peripheral cells, those adjacent to the basement membrane of the seminiferous, are the spermatogonia, which divide by mitosis. Some of the daughter cells produced from these mitotic divisions remain spermatogonia and continue to produce additional spermatogonia. The others divide through mitosis and differentiate to form primary spermatocytes Meiosis begins when the primary spermatocytes divide. Each primary spermatocytes passes through the first meiotic division to become two secondary spermatocytes. NMT 04102 Anatomy and Physiology NTA Level 4, Semester 1
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Each secondary spermatocyte undergoes a second meiotic division to produce two even smaller cells called spermatids. Each spermatid undergoes the last phase of spermatogenesis called spermiogenesis to form a mature sperm cell or spermatozoon. Each spermatid develops a head, mid piece and a tail, or flagellum. The head contains chromosomes and at the leading end it has a cap, acrosome, which contains enzymes necessary for the sperm cells to penetrate the female cell. The whole process is under the hormonal influence produced by interstitial cells and sustentacular cells.
Refer Students to Handout 11.3: Seminiferous Tubule Cross Section
Step 4: Key Points (5 minutes)
The male reproductive system consists of those organs whose function is to produce a new individual or an offspring Sperm cells originate from germ cells Spermatogenesis is the process of sperm cell development
Step 5: Evaluation (5minutes)
What are main organs of the male reproductive system? Explain the process of spermatogenesis
ASK students if they have any comments or need clarification on any points
References
Gray. H (2008) Gray’s Anatomy: anatomical basis for clinical practice. 40th Ed. Elsevier, Seeley, R. R., Stephens, T. D. & Tate, P. (2003). Anatomy and Physiology. New York: McGraw-Hill Thibodeau, G. A., Patton, K. T. (1999). Anatomy & Physiology. Saint Louis: Mosby, Von Hoffman Press, Inc Waugh, A. & Grant, A. (2006). Ross and Willson Anatomy and Physiology in Health and illness. United Kingdom: Churchill Livingstone Elservier.
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Handout 11.1: Structure of the Male Reproductive System
Source: www.studentconsult.com
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Handout 11.2: Structure of the Testes
` Source: www.studentconsult.com
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Handout 11.3: Seminiferous Tubule Cross Section
Source: www.studentconsult.com
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Session 12: Structure and Function of the Mouth, Oesophagus and Stomach Total Session Time: 120 Minutes Prerequisites None Learning Tasks By the end of this session, students are expected to be able to: Identify the organs of the alimentary system Describe the structure and functions of the, mouth eosophagus and the stomach Resources Needed Flipcharts, Marker pens and Masking tape Black/white board and chalk/whiteboard markers Anatomical charts Anatomical models and atlas LCD and Computer Handout 12.1: General Structure of the alimentary system Handout 12.2: Organs of the Alimentary System Handout 12.3: Structure of the Mouth and Tongue Handout 12.4: Structure of the Oesophagus Handout 12.5: Structure of the Stomach SESSION OVERVIEW Step
Time
Activity/Method Presentation
Content
1
05 Minutes
Presentation of the Session and Learning Tasks
2
30 Minutes
3
75 Minutes
4
05 Minutes
Presentation
Key Points
5
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Evaluation
Presentation, Buzz Presentation, Group Discussion
Organs of the Alimentary System Structure and Functions of the Mouth, Esophagus and the Stomach
SESSION CONTENT Step 1: Presentation of Session Title and Learning Tasks (5 Minutes) READ or ASK students to read the Learning tasks and clarify ASK students if they have any questions before proceeding
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Step 2: Organs of the Alimentary System (30 minutes) Activity: Buzzing (5 minutes) ASK the students to pair up and write down principle and accessory organs of the alimentary system for 5 minutes ALLOW few student to provide responses and let other pairs to provide unmentioned responses CLARIFY and summaries by using the information below
The digestive system is the collective name used to describe the alimentary canal, some accessory organs and a variety of digestive processes which take place at different levels in the diet for absorption. The activities in the digestive system follow five main stages: o Ingestion, propulsion digestion, absorption, and elimination. Alimentary tract is a long tube through which food passes. It starts from the mouth and ends at anus.
The Organs of the Digestive System Principle organs o Mouth o Pharynx o Oesophagus o Stomach o Small intestine o Large intestine o Rectum and anal canal Accessory organs o 3 pairs of salivary glands o Pancreas o Liver and the biliary tract The organ and glands are linked physiologically as well as anatomically in that digestion and absorption occur in stages, each stage being dependent upon the previous stage or stages. Refer Students to Handout 12.2: Organs of the Alimentary System
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Step 3: Structure and Functions of the Mouth, Oesophagus and Stomach (75 minutes) Activity: Small Group Discussion ( 30 minutes) DIVIDE students into small manageable groups ASK students to discussion in groups on structure and functions of the mouth 10 minutes ALLOW groups ask students to provide their response for 2 minutes each CLARIFY and summaries by using the contents below The Mouth or Oral Cavity Structures associated with the mouth o Anteriorly - by the lips o Posteriorly – It is continuous with the oropharynx o Laterally – By the muscle of the cheeks o Superiorly – By the bony hard palate and muscular soft palate o Inferiorly – By the muscular tongue and the soft tissues of the floor of the mouth. The oral cavity is lined throughout with mucus membrane, consisting of stratified squamous mucus secreting gland. The part of the mouth between the gums (areolar ridges) and the cheeks is the vestibule and the remainder of the cavity is the mouth proper. The roof of the cavity is formed by the hard palate and the soft palate A cone shaped prolongation hangs down in the back of the mouth is called uvula. The mucus membrane that covers the whole cavity continues in two folds where we can find the palatine tonsil. The Tongue This is the voluntary muscular structures which occupies the floor of the mouth. It is attached to the hyoid bone in the neck. On the surface of the tongue we find the numerous papillae (small projections), containing nerve endings of the sense of taste buds. There are three varieties of papillae. o Valvate papillae Usually between 8 and 12 altogether, are arranged in an inverted, V shaped toward the base of tongue. These are the largest of the papillae and are the most easily seen. o Fungiform papillae It is situated mainly at the tip and the edge of the tongue and are more numerous than the Valvate papillae o Fusiform papillae Are the smallest of the 3 types There are most numerous on the surface of the anterior two – third of the tongue. Blood Supply The main anterior blood supply to the tongue is by the lingual branch of the external carotid artery. NMT 04102 Anatomy and Physiology NTA Level 4, Semester 1
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Venous drainage is by the lingual vein which joins the internal jugular vein.
Nerve Supply The hypoglossal nerves (12th cranial nerves) which supply the voluntary muscle tissue. The lingual branch of the mandibular nerves which are the nerves of somatic (ordinary) sensation i.e. pain, temperature and touch. The facial and glossopharyngeal nerves (7th and 9th cranial nerves) which are the nerves of the special sensation of taste We can feel four tastes o Sour o Sweet o Bitter o Salt The Function of the Tongue An organ of taste Helps in mastication Assists in swallowing Assists in speech Sublingual Glands Under the surface of the tongue is connected to the floor with a small string called frenulum on the floor of mouth under the tongue the sublingual glands and the submandibular glands enter. The duct from the 3rd pair of salivary glands – the parotid glands enter the mouth opposite the 2nd upper molar. The 3 pair of glands that secrete: o Water 90% o Enzyme – ptyalin – salivary amylase. o Mucin – lubricant o Small amount of calcium. Functions of Saliva Moisten the food and the mouth. Moisten and lubricant the food. Ptyalin converts carbohydrates Stimulate the taste buds. Clean the mouth and the teeth Teeth The teeth are embedded in the alveoli or sockets of the alveolar ridges of the mandible and the maxilla. Each individual develops two set of teeth. o The temporary teeth or deciduous or the milky teeth, there are 20teeth in number, 10 in each jaw. o The first erupt 5-8 months. o They are complete at 2 years. o The permanent teeth 32 in number, they replace the milky teeth at the age of 6 years and usually they are complete at the age 26yrs. NMT 04102 Anatomy and Physiology NTA Level 4, Semester 1
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According to their shape and position they are classified into four groups. o Incisors. 2 in number on each side of the jaws. o They are sharp edged for biting the food. One root. o Canines 1 in number. o On each side of the jaw. Have large conical crows for grasping the food. One root o Premolars 2 on each side. o They have two elevations or cusps on the crown. One root. o Molars 3 on each side. o The largest teeth with 4-5cusps for grinding or (chewing) the food. o The upper molars have 3 roots and the lower has 2 roots.
Structure of a Tooth Although the shape of different teeth vary, the structure is the same and consists of:o The crown - the part which protrudes from the gum. o The root – the part embedded in the bone. o The neck – slightly narrowed region where the crown merges with the root. The tooth consists of mainly dentine a very hard material. The enamel covers exposed portion of the tooth and is even harder than dentine. The hallow cavity is called pulp, it consists of connective tissue with blood vessels and nerves passing down to the root in fine canals. The teeth are fixed to the gum by special cement and a strong layer of connective tissue. Blood Supply Most of the blood supply to the teeth is by branches of the maxillary arteries. The venous drainage is by a number of veins which empty into the internal jugular veins. Nerve Supply The nerve supply to the upper teeth is by branches of the maxillary nerve and to the lower teeth by branches of the mandibular nerves. These are both branches of the trigeminal nerves (5th cranial nerves). Refer Students to Handout 12.3: Structure of the Mouth and the Tongue The Pharynx The oropharynx and laryngopharynx are passages common to both the respiratory and digestive system. Food passes from the oral cavity into the pharynx then to the oesophagus bellow. When food reaches the pharynx swallowing is no longer under voluntary control. The Oesophagus This is a 25cm long muscular tube consists of 4 layers of tissue Lies behind trachea extending from the pharynx with an upper sphincter – cricopharyngeal sphincter which prevents air passing into oesophagus when the act of swallowing takes place and prevent content from oesophagus enter the trachea. When the oesophagus enters through the diaphragm it curves up and into the stomach we can find the cardiac sphincter that prevents the gastric acid to enter the oesophagus.
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Blood Supply Arterial blood supply: o The thoracic region of the oesophagus is supplied mainly by the Oesophageal arteries, branches from the aorta, the abdominal regions is supplied by branches from the inferior phrenic arteries and the left gastric branch of the coeliac artery. Venous drainage: o From the thoracic region venous drainage is into the azygos and hemiazygos veins, the abdominal part drains into the left gastric veins. Nerve supply: o Sympathetic and parasympathetic nerves terminate in the myenteric and sub mucosal plexuses. Parasympathetic fibers are branches of the vagus nerves. Swallowing or Deglutition This occurs in 3 stages after mastication is complete and the bolus has been formed. It is initiated voluntarily but completed by a reflex (involuntary) action. It takes 9 second for a wave of peristalsis to pass the bolus from the pharynx to the stomach. The first stage occurs when the tongue forces the bolus to the pharynx is voluntary. The impulses to continue the process are coming from the swallowing center in the brain stem and these impulses are transferred to the swallowing receptors in the pharynx. The soft palate rises and closes the nasopharynx. The epiglottis moves backwards to prevent food entering the trachea. The cricopharyngeal sphincter relaxes and a wave of peristalsis pushes the bolus into the oesophagus while larynx is pushed upwards. The wave of peristalsis continues and the cardiac sphincter open up and the bolus enters the stomach. Refer Students to Handout 12.4: Structure of the Oesophagus The Stomach Is a J shaped dilated portion of the alimentary tract situated in the epigastric, umbilical and left hypochondriac regions of the abdominal cavity. Structures associated with the stomach. o Anteriorly – Left lobe of liver and anterior abdominal wall. o Posteriorly – Abdominal aorta, pancreas, spleen, left kidney and adrenal glands. o Superiorly – Diaphragm, oesophagus and left lobe of liver. o Inferiorly – Transverse colon and small intestine o To the left – diaphragm and spleen. o To the right – liver and duodenum. Structure of the Stomach The stomach is continuous with the eosophagus at the cardiac sphincter and with the duodenum at the pyloric sphincter. It has a greater curvature and a lesser curvature, the upper part of the stomach is called fundus, middle portion body and the lowest part the antrum. The pyloric sphincter relaxes when the food enters the duodenum. Inside the stomach there are folds of mucosa membrane called rugae which help the stomach to extend during eating. NMT 04102 Anatomy and Physiology NTA Level 4, Semester 1
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Wall of stomach The four layers of tissues that comprise the basic structure of the alimentary canal are found in the stomach. Muscle layer. o This consists of three layers of smooth muscle fibres: An outer layer of longitudinal fibres An middle layer of circular fibres An inner layer of oblique fibres. o In this way the stomach is different from other regions of alimentary tract as it has three layers of muscles instead of two. o This arrangement allows for peristaltic movement, circular muscle is strongest in the pyloric antrum and sphincter. o There are 4 numerous gastric glands situated below the surface in the mucous membrane, they consist of specialized cells that secrete gastric juice e.g. Mucus Enzymes Hydrochloric acid and intrinsic factor Histamine and serotonins o This production is mainly in the upper part and middle part of the stomach. o In the lower part the hormone gastrin is produced by the G – cells. o A large amount of lymph nodes are situated here and prevent the spread of infections from organs to peritoneum. o A small omentum hangs between the liver and stomach and between liver and duodenum. o The stomach may be able to store 1litre of food for 4-6 hrs, peristalsis in the lower part of the stomach is stronger where the mixture is called chyme. Refer Students to Handout 12.5: Structure of the Stomach
Blood Supply Arterial blood is supplied to the stomach by branches of the celiac artery. Venous drainage is into the portal vein Nerve Supply The sympathetic supply to the stomach by branches of the coeliac plexus and the parasympathetic supply is from the vagus nerves. Sympathetic stimulation reduces the motility of the stomach and the secretion of gastric juice, vagal stimulation has the opposite effect. Functions of the Stomach Temporary storage of food allowing time for digestive enzymes, pepsin to act. Chemical digestion pepsin converts proteins to polypeptides. Mechanical breakdown the three smooth muscle layers enable the stomach to act as a chime, gastric juice is added and the contents are liquefied to chyme. Limited absorption of water, alcohol and some lipid soluble drugs. Non specific defense against microbes provided by hydrochloric acid in gastric juice. Vomiting may be a response to ingestion of gastric irritants e.g. microbes or chemicals.
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Preparation of iron for absorption further along the tract the acid environment of the stomach solubilizes iron salts, which is required before iron can be absorbed. Production of intrinsic factor needed for absorption of vitamin B12 in the terminal ileum. Regulation of the passage of gastric contents into the duodenum, when the chyme is sufficiently acidified and liquefied, the pyloric antrum forces small jets of gastric contents through the pyloric sphincter into the duodenum. Secretion of gastrin hormone.
Step 4: Key Point (5 minutes)
Digestive system is the system that deals with digestion and absorption of food. It involves 5 main processes i.e. ingestion, propulsion, digestion, absorption, and elimination. The stomach is temporary storing food in the process of digestion. The four gastric glands situated below the tongue consist of specialized cells that secrete Mucus, Enzymes, Hydrochloric acid and intrinsic factor, Histamine and serotonins which help in digestion. The tongue is a sensory organ containing special sensation of taste that includes sour, sweet, and bitter
Step 5: Evaluation (5 minutes)
Define the alimentary system List the functions of the stomach Mention the senses found in the tongue
ASK students if they have any comments or need clarification on any points
Reference
Gray. H (2008) Gray’s Anatomy: anatomical basis for clinical practice. 40th Ed. Elsevier, Patton, K. T & Thibodeau G. A. (2007) Anatomy and physiology. (6th ed). China: Mosby. Roby, P. (1993). Anatomy and physiology (6th Ed.). USA: Pearson Custom. Seeley, R. R., Stephens, T. D. & Tate, P. (2003). Anatomy and Physiology. New York: McGraw-Hill Thibodeau, G. A., Patton, K. T. (1999). Anatomy & Physiology. Saint Louis: Mosby, Von Hoffman Press, Inc Waugh, A. & Grant, A. (2006). Ross and Willson Anatomy and physiology in Health and illness. United Kingdom: Churchill Livingstone Elservier. .
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Handout 12.1: General Structure of the Alimentary System Four Layers of Tissue which form Walls of Alimentary Tract Adventitia or outer covering (Peritoneum) o This is the largest serous membrane of the body. It consists of a closed sac with two layer of serous membrane; it contains a small amount of serous fluid within the abdominal cavity. o It is richly supplied with blood and lymph vessels, and contains a considerable number of lymph nodes. o It provides a physical barrier to local spread of infection and can isolate infective organs such as appendicitis, preventing involvement of other abdominal structures. o It has two layers The parietal layer which lies the abdominal wall The visceral which cover the organs (viscera) within the abdominal and pelvic cavities. The two layers of peritoneum are actually in contact and friction between them is prevented by the presence of serous fluid secreted by the peritoneal cells, thus the peritoneal cavity is only a potential cavity. Muscle layer o This consists of two layers of smooth muscle (involuntary). o Between the layers there are lymph vessels and a plexus (group) of sympathetic and parasympathetic nerves called Auesbachs plexus or myenteric. o Peristalsis occurs because of contraction as waves in these muscle layer. o The function of peristalsis is to move the food forward and to help the food to be mixed with the digestive juices. o The contracted of circular muscles fibers delay the movement of food at the specific points. So digestion and absorption can take place. o The sub mucosa layer. It is a layer of loose connective tissue consisting of many plexuses of blood vessels, nerves, lymph vessels and varying amount of lymphoid tissue. The nerve plexuses from the autonomic nervous system are called sub mucosal or maissner’s plexus. o Mucosa lining This consists of 3 layers of tissue o Mucous membrane formed by columnar epithelium is the inner most layer and has three main functions: Protection Secretions Absorption o Lamina proprie consisting of loose connective tissue, which supports the blood vessels that nourish the inner epithelial layer and varying amount of lymphoid tissue that has a protective function. o Muscularis mucosa is a thin layer of smooth muscle that provides involutions of the mucosa layer e.g. gastric glands, villi. o Mucous membrane are part of the tract which are subject to great wear and tear or mechanical injury this layer consists of stratified squamous epithelium with mucus secreting goblet cells. NMT 04102 Anatomy and Physiology NTA Level 4, Semester 1
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o Mucus lubricates the walls of the tract and protects them from digestive enzymes. o Below the surface in the regions lived with columnar epithelium are collections of specialized cells or glands, which pour their secretions include. Saliva from the salivary glands Gastric juice from the gastric glands Intestinal juice from the intestinal glands Pancreatic juice from the pancreas Bile from the liver. These are the digestive juices and they contain enzymes which chemically breakdown food. Nerve supply o The alimentary tract is supplied by nerves from both divisions of the autonomic nervous system i.e. the parasympathetic supply (vagus nerve) stimulation causes smooth muscle contraction and the secretion of digestive juices also sympathetic supply that help in reducing the smooth muscles contraction and glandular secretions. Blood supply o Arterial blood supply o The oesophagus is supplied by paired oesophageal arteries branches from the thoracic aorta. o In the abdomen and pelvis. o The aliment tract, pancreas, liver and biliary tract are supplied by the unpaired branches from the aorta The coeliac artery The superior Inferior mesenteric artery venous drainage. o In the thorax venous blood from the oesophagus passes in the oesophageal veins to the azygos and hemiazygos veins, some blood from the lower part of the oesophagus drains into the left gastric vein. o In the abdomen and pelvis. o The veins that drain blood flow the lower part of the oesophagus, the stomach pancreas, small and large intestine and most of rectum join to form the portal vein. o Blood from the lower part of the rectum and the anal canal drains into the internal iliac veins. o This blood is delivered directly into the inferior Vena cava.
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Handout 12.2: Organs of the Alimentary System
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Source: www.studentconsult.com
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Handout 12.3: Structure of the Mouth and the Tongue
Source: www.studentconsult.com
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Handout 12.4: Structure of the Oesophagus
Source: www.studentconsult.com
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Handout 12.5: Structure of the Stomach.
Source: www.studentconsult.com
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Source: www.studentconsult.com
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Session 13: Structure and Function of the Small and Large Intestines Total Session Time: 120 Minutes Prerequisites None Learning Tasks By the end of this session, students are expected to be able to: Describe the Structure and functions of the small. Describe the Structure and functions of large intestines Resources Needed Flipcharts, Marker pens and Masking tape Black/white board and chalk/whiteboard markers Anatomical charts, models and atlas LCD and Computer Handout 13.1: Structure of the Small and Large Intestine Handout 13.2: Intestinal Wall and Villi Handout 13.3: Blood Supply to the Digestive Tract Worksheet 13.1 Layers of Small Intestines SESSION OVERVIEW Step
Time
Activity/Method
Content
1
05 Minutes
Presentation
Presentation of the Sessions and Learning Tasks
2
35 Minutes
Presentation,
Structure and Functions of the Small Intestines
3
70 Minutes
Presentation, Group Discussion
Structure and Functions of the Large Intestines
4
05 Minutes
Presentation
Key Points
5
05 Minutes
Presentation
Evaluation
SESSION CONTENT Step 1: Presentation of Session Title and Learning Tasks (5 minutes) READ or ASK students to read the learning tasks and clarify ASK students if they have any questions before proceeding
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Step 2: Structure and Functions of the Small Intestine (35 minutes) Structure The small intestine is a continuous with the stomach at the pyloric sphincter and leads into the large intestine at the ileocaecal valve. It is approximately 5metres long. The small intestine comprises of three main sections which are continuous with each other. o Duodenum This lies in a C – shape curved around pancreas. It is about 25cm long. Through the sphincter of oddi further down to the Ampulla of vater the bile and the pancreatic juices enter the duodenum. o Jejunum This is the middle section of the small intestine and is about 2 meters long. Ileum This is a terminal section, is about 3 meters long and ends at the ileocaecal valve; it controls the flow of material from the ileum to the caecum, the first part of large intestine, and prevents regurgitation. As describe before the small intestines have 4 layers. In the inner layer the mucus membrane is arranged in folds rugae which increase the surface area for absorption and secretions. The total area for absorption is 250m2. The surface of the membrane is covered with small villi. (small finger like projections) Each villus consists of a network of blood capillaries and a central lacteal connected with a lymph vessel in order to absorb fat (chyle). A single layer of epithelium cells called Enterocytes line the villi. Each cell has ≈ 600microvilli; between the villi there are many intestinal glands that secrete the digestive enzymes. In the duodenum the gland secretes mucus that protects the walls from hydrochloric acid. There are many lymph nodes surround the small intestines and in the distal part of the ileum.
Refer Students to: Handout 13.1: Structure of the Small and Large Intestine Handout 13.2: Intestinal Wall and Villi
Blood Supply The superior mesenteric artery supplies the whole of the small intestine and venous drainage is by the superior mesenteric vein which joins other veins to form portal vein. Nerve Supply Both the sympathetic and parasympathetic nerves supply to the small intestine. Functions of the Small Intestine On ward movement of its content which is produced by peristalsis Secretion of intestinal juice
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Protection against infection by microbes that have survived the antimicrobial action of the hydrochloric acid in the stomach. Completion of chemical digestion of carbohydrates, protein and fats in the enterocytes of the villi. Secretion of hormones cholecystokinin (CCK) and secretion Absorption of nutrients
Step 3: Structure and Functions of the Large Intestine (70 minutes) Structure This is about 1.5 meters long beginning at the caecum in the right iliac fossa and terminating at the rectum and anal deep in the pelvis. Its lumen is larger than that of the small intestine. It is divided in several parts. o The caecum. o The ascending colon o The transverse colon o The sigmoid colon The Caecum This is the first part of the colon. It is a dilated region which has a blind end inferiorly and is continuous with the ascending colon superiorly. Just below the ileocaecal valve opens from the ileum. The vermiform appendix is a fine tube closed at one end, which leads from the caecum below ileocaecal valve. It contains lymphoid tissue. Inflammation of the appendix is called appendicitis. The Ascending Colon It passes upwards to the hepatic flexure just below the liver. The Transverse Colon This hangs in a fold of peritoneum (the greater omentum) where it passes across the abdominal cavity to the splenic flexure. The Descending Colon It passes down the left side of the abdominal cavity then curves towards the midline. After it enters the pelvic and it is known as the sigmoid colon. The Sigmoid Colon This part describe an S – shaped curve in the pelvic then continue down wards to become the rectum. The Rectum This is slightly dilated section of the colon about 13cm long. It leads from the sigmoid colon and terminates in the anal canal.
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The Anal Canal This is a short passage about 3.8 cm long in the adult and leads from the rectum to the exterior. It is controlled by two sphincters namely o The internal anal sphincter. This is constructed of circular smooth muscle fibre, this is an involuntary muscle. The rectum is usually empty. Until peristaltic movement pass faeces from the sigmoid flexure into the rectum. The extended rectum cause impulses to pass to the brain and give impulses to contractions in descending colon, sigmoid flexure and rectum at the same time the internal sphincter relaxes. o The external canal sphincter This is under conscious control through the pudendal nerve. As the internal sphincter relaxes at the same time signals are passed to the brain and the desire to defecate is conscious. If the time is appropriate the external sphincter relaxes voluntarily and the faeces pass. Defecation infant is involuntary as the nervous system is not fully developed. When defecation is voluntary post ponded the feeling of fullness and need to defecate tends to fade. Repeated suppression of the reflex may lead to constipation. There are some differences in the layers of tissue compared to the rest of the alimentary canal. The longitudinal muscles don’t form a continuous layer but are instead arranged in three separated longitudinal bands that are shorter than the length of colon In the submucosal layer there is more lymphatic tissues. The mucus membrane secretes a large amount of mucus to the lubrication for the passage of faeces. The colon doesn’t have folds and villi as it is in small intestines. Handout 13.1: Structure of the Small and Large Intestine Blood Supply Arterial supply is mainly by the superior and inferior mesenteric arteries. Venous drainage is mainly by the superior and inferior mesenteric veins. Refer Students to Handout 13.3: Blood Supply to the Digestive Tract Functions of the Large Intestines Absorptions o The contents of the ileum which pass through the ileocaecal valve into the caecum are fluid, even though some water has been absorbed in the small intestine. o In the large intestine the absorption of water continues until the familiar semisolid consistency of faeces is achieved. o Mineral salts, vitamins and some drugs are also absorbed into the blood capillaries from the large intestine. Microbial activity. o The large intestine is heavily colonized by certain types of bacteria which synthesize NMT 04102 Anatomy and Physiology NTA Level 4, Semester 1
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o o o o
vitamin K and folic acid. They include Escherichia coli, Enterobacter aerogenes, streptococcus faecalis and clostridium perfringens (welchi). These microbes are commensals in humans. They may become pathogenic if transferred to another part of the body. E.g. Escherichia coli may cause cystitis if it gains access to the urinary bladder. Large numbers of microbes are present in the faeces.
Activity: Group Discussion (15 minutes) DIVIDE students into small manageable groups Refer students to Worksheet 13.1: Layers of Small Intestines
ASK students to discuss on Layers of Small Intestines for 5 minutes ALLOW one group to responses and let others provide unmentioned response CLARIFY and summaries by using the information below
Step 4: Key Points (5 minutes)
The small intestine is a continuous with the stomach at the pyloric sphincter and leads into the large intestine at the ileocaecal valve. The duodenum, j jejunum, and ileum are the parts of the small intestines. These are the organs responsible for digestion, absorption of food as well as excretion and elimination of waste products. The large intestine is divided into ascending, transverse, descending and sigmoid colon.
Step 5: Evaluation (5 minutes)
Define small intestine. Mention the parts of the small intestine List the functions of the large intestine
ASK students if they have any comments or need clarification on any points
Reference
Gray. H (2008) Gray’s Anatomy: anatomical basis for clinical practice. 40th Ed. Elsevier, Patton K. T & Thibodeau G. A. (2007) Anatomy and physiology. (6th ed). China: Mosby. Roby, P. (1993). Anatomy and physiology (6th Ed.). USA: Pearson Custom. Seeley, R. R., Stephens, T. D. & Tate, P. (2003). Anatomy and Physiology. New York: McGraw-Hill Thibodeau, G. A., Patton, K. T. (1999). Anatomy & Physiology. Saint Louis: Mosby, Von Hoffman Press, Inc
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Waugh, A. & Grant, A. (2006). Ross and Willson Anatomy and physiology in Health and illness. United Kingdom: Churchill Livingstone Elservier.
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Handout 13.1: Structure of the Small and Large Intestine
Source: www.studentconsult.com
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Handout 13.2: Intestinal Wall and Villi
Source: www.studentconsult.com
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Handout 13.3: Blood Supply to the Digestive Tract
Source: www.studentconsult.com
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Worksheet 13.1: Exercise on Layers of the Small Intestine
1………………………………. 2………………………………. 3………………………………. 7………………………………. 9………………………………. 10…………………………....... 11…………………………....... 12a……………………………. 12b…………………………… 13…………………………….. 14……………………………..
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Session 14: Structure and Function of the Accessory Organs of the Digestive System Total Session Time: 120 Minutes Prerequisites None Learning Tasks By the end of this session, students are expected to be able to: Identify the accessory organs of the digestive system. Describe the Structure and functions of the accessory organs of the digestive system Resources Needed Flipcharts, Marker pens and Masking tape Black/white board and chalk/whiteboard markers Anatomical models, charts and atlas LCD and Computer Handout 14.1: Structure of the Pancreas Handout 14.2: Structure of the Liver Handout 14.3: Structure of the Biliary Tract SESSION OVERVIEW Step
Time
Activity/Method
Content
1
05 Minutes
Presentation
2
25 Minutes
3
80 Minutes
4
05 Minutes
Presentation
Key Points
5
05 Minutes
Presentation
Evaluation
Presentation of the Session and Learning Tasks
Presentation, Brainstorm Presentation, Group Discussion
Accessory Organs of the Digestive System Structure and Functions of the Accessory Organs of the Digestive System
SESSION CONTENT Step 1: Presentation of Session Title and Learning Tasks (5 minutes) READ or ASK students to read the learning tasks and clarify ASK students if they have any questions before proceeding
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Step 2: Accessory Organs of the Digestive System (25 minutes) Activity: Buzzing (5 minutes) ASK the students to pair up and write down accessory organs of the digestive system for 5 minutes ALLOW few student to responses and let other pairs to provide unmentioned responses CLARIFY and summaries by using the information below
Pancreas Liver Biliary tract(bile duct and gallbladder)
Step 3: Structure and Functions of the Accessory Organs of the Digestive System (80 minutes) Activity: Small Group Discussion ( 30 minutes) DIVIDE students into small manageable groups ASK students to discussion in groups on structure and functions of the accessory organs of the digestive system 10 minutes ALLOW groups ask students to provide their response for 2 minutes each CLARIFY and summaries by using the contents below The Pancreas Pancreas is an endocrine and exocrine gland situated just behind the stomach. The size is 12 – 15 cm and the gland is pink gleyish It weigh 60gms The pancreatic dust joins together with the common bile duct ad enter the duodenum at the ampulla of vater. The tail of pancreas is in contact with the spleen. Structure The pancreas is an elongated, tapered organ located across the back of the abdomen, behind the stomach. The right side of the organ (called the head) is the widest part of the organ and lies in the curve of the duodenum (the first section of the small intestine). The tapered left side extends slightly upward (called the body of the pancreas) and ends near the spleen (called the tail). The pancreas is made up of two types of tissue: o Exocrine tissue The exocrine tissue secretes digestive enzymes. These enzymes are secreted into a network of ducts that join the main pancreatic duct, which runs the length of the pancreas. NMT 04102 Anatomy and Physiology NTA Level 4, Semester 1
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o Endocrine tissue The endocrine tissue, which consists of the islets of Langerhans, secretes hormones into the bloodstream. Refer students to Handout 14.1: Structure of the Pancreas Functions of the Pancreas The pancreas has digestive and hormonal functions: o The enzymes secreted by the exocrine tissue in the pancreas help break down carbohydrates, fats, proteins, and acids in the duodenum. o These enzymes travel down the pancreatic duct into the bile duct in an inactive form. o When they enter the duodenum, they are activated. o The exocrine tissue also secretes bicarbonate to neutralize stomach acid in the duodenum. o The hormones secreted by the endocrine tissue in the pancreas are insulin and glucagon (which regulate the level of glucose in the blood), and somatostatin (which prevents the release of the other two hormones). The Liver This is the largest and vital organ in the body weighing 1- 2.5kg situated in the upper quadrant of the abdominal cavity, it is divided into the right and left lobes separated by the falciform ligament. The liver is completely enclosed in the peritoneum. The hilum or portal tissue is the door of the liver where all the blood vessels and nerves entering and leaving the liver except the hepatic vein. Structure The liver is composed by a large amount of lobes each lobule is cylindrical in shape ≈ 2mm. Each lobule is surrounded by a connective tissue; each lobule has a central vein that drains the blood to the hepatic vein. The large liver cells (hepatocytes) are radiating out from the central vein and between these cords of cells we can find the sinusoids (blood vessel with incomplete walls) capillary. Blood vessel lived with phagocytic tissue (The kupffer cells) between the cells we also find the bile canaliculus. The bile canaliculus join to form intralobular ducts which unit and become the right and left hepatic duct. Around to periphery of each lobule are five to seven cluster of vessels called the portal triad every triad consist of:o A branch of hepatic artery. o A branch of hepatic portal vein o A branch of interlobular bile duct. Blood inter the liver from two sources o The hepatic artery which carries oxygenated blood from the lungs to the liver and it also carries fat from the lymphatic system. o The hepatic portal vein that carries blood directly from the digestive system. o The blood passes through the sinusoid → hepatic vein → vena cava → right atrium. NMT 04102 Anatomy and Physiology NTA Level 4, Semester 1
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Refer Students to Handout 14.2: Structure of the Liver The Functions of the Liver Secretion of bile, an exocrine function, which helps carry away wastes and breakdown fats in the small intestines during digestion. Storage of glycogen which will be converted to glucose when the blood glucose level is low. Also the liver is able to convert amino acids to glucose. Stored fat is broken down to provide energy and carbohydrates, and amino acids are converted to fat to be stored. Storage of vitamins in large amounts are A, D and B12. The liver is able to synthesize vitamin A from carotene. Storage of iron in the form of ferritin derived from worn out red blood cells. Re used in blood formation. Production of clotting factors e.g. fibrinogen, pro-thrombin and factor VII, thus regulating blood clotting. Production of heat. The liver uses the considerable amount of energy, has a high metabolic rate and produces a great deal of heat. Detoxification of drug and noxious substances. These include ethanol (alcohol) and toxins produced by microbes. Metabolism of ethanol. This follows consumption of alcohol. Production of the plasma proteins e.g. albumin, globulin etc. Deamination. The removal of nitrogen of the amino acids to form ammonia. The ammonia is converted by the liver to uric acid as a waste product. Resisting infections by producing immune factors and removing bacteria from the blood stream. Production of cholesterol and special proteins to help carry fat through the body. The Biliary Tract This is composed of bile duct and gall bladder. Structure The gall bladder is a pear shaped sac attached under the surface of the right lobe of the liver. The gall bladder can store ≈ 60 mls of bile in a very concentrated form. The right and left hepatics from the common hepatic duct, this duct enters the gall bladder with the bile through the cystic duct. When the bile leave the gall bladder through the cystic duct it enters common bile duct and join together with the pancreatic duct and continue through the hepatopacreatic sphincter (oddi) in the duodenum. Composition of Bile About 500ml of bile are secreted by the liver daily consisting of:o Water o Mineral salts o Mucous NMT 04102 Anatomy and Physiology NTA Level 4, Semester 1
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o Bile pigments, mainly bilirubin Bile pigment derived from the breakdown of erythrocytes, in the bowel it is converted to urobilonogen, some is reabsorbed in the blood and some excreted with faeces and urine. Bile salts, which are derived from the primary bile acids, choric acid and chenodeoxycholic acid. Bile salts break up lipids into fatty acids and glycerol in the small intestine. The bile salts are reabsorbed from the lower part of small intestines and reused. o Cholesterol. Functions of Gall Bladder Reservoir for bile Concentrate bile by up to 10 -15 fold, by absorption of water through the walls of the gall bladder. Release of stored bile. o When the muscle of the walls of the gall bladder contracts bile passes through the bile ducts to the duodenum, contractions is stimulated by. The hormone cholecystokinin (CCK) secreted by the duodenum. The presence of fat and acid chime in the duodenum. Relaxation of the hepatopacreatic sphincter of oddi is caused by cck and is reflex response to contractions of gall bladder. Refer Students to Handout 14.3: Structure of the Biliary Tract
Step 4: Key Points (5minutes)
The liver is the largest and vital organ in the body weighing ≈ 1- 2.5kg situated in the upper quadrant of the abdominal cavity. It is divided into the right and left lobes separated by the falciform ligament The main functions of the liver are categorized into secretion, storage, digestion and deamination of various substances. Pancreas is an important organ which plays an important role in carbohydrate metabolism through production of insulin. The gallbladder secretes and store bile
Step 5: Evaluation (5 minutes)
Mention the accessory organs of the digestive system What are the functions of the liver? What is the importance of insulin in the body?
ASK students if they have any comments or need clarification on any points
Reference
Gray. H (2008) Gray’s Anatomy: anatomical basis for clinical practice. 40th Ed. Elsevier, Patton K. T & Thibodeau G. A. (2007) Anatomy and physiology. (6th ed). China: Mosby.
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Roby, P. (1993). Anatomy and physiology (6th Ed.). USA: Pearson Custom. Seeley, R. R., Stephens, T. D. & Tate, P. (2003). Anatomy and Physiology. New York: McGraw-Hill Thibodeau, G. A., Patton, K. T. (1999). Anatomy & Physiology. Saint Louis: Mosby, Von Hoffman Press, Inc Waugh, A. & Grant, A. (2006). Ross and Willson Anatomy and physiology in Health and Illness. United Kingdom: Churchill Livingstone Elservier.
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Handout 14.1: Structure of the Pancreas
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Handout 14.2: Structure of the Liver
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Handout 14.3: Structure of the Biliary Tract
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Session 15: Digestion and Metabolism of Food in the Body Total Session Time: 120 Minutes Prerequisites None Learning Tasks By the end of this session, student will be able to: Describe the process of food digestion Describe the metabolism of food in the body Resources Needed Flipcharts, Marker pens and Masking tape Black/white board and chalk/whiteboard markers Anatomical models, charts and atlas LCD and Computer SESSION OVERVIEW Step
Time
Activity/Method
Content
1
05 Minutes
Presentation
2
55 Minutes
3
50 Minutes
4
05 Minutes
Presentation
Key Points
5
05 Minutes
Presentation
Evaluation
Presentation of the Session and Learning Tasks
Presentation, Process of Food Digestion Buzz Presentation, Metabolism Food in the Body Group Discussion
SESSION CONTENT Step 1: Presentation of Session Title and Learning Tasks (5 minutes) READ or ASK students to read the Learning tasks and clarify ASK students if they have any questions before proceeding
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Step 2: Digestion of Food (55 minutes) Activity: Buzzing (5 minutes) ASK the students to pair up and write down types of digestive system for 5 minutes ALLOW few student to responses and let other pairs to provide unmentioned responses CLARIFY and summaries by using the information below
Digestion is the mechanical and chemical breakdown of food into smaller components that are more easily absorbed into the blood stream.
Mechanical Digestion Consists of all movements of the digestive tract that brings about: o Change in the physical state of ingested food from completely large solid pieces into minute particles, there by facilitating chemical digestion. o Churming of the content of the GI lumen in such a way that they become well mixed with digestive juices and come into contact with intestinal mucosal wall ready for the absorption. o Propelling food forward along the digestive tract. Mastication The tongue, cheeks and lips play and important role in keeping food material between the cutting or grinding surfaces of the teeth when chewing. In addition reducing particle size ,movements serve to mix food and saliva in preparation for swallowing Deglutition Deglutition or swallowing is divided into formation and movement of food bolus from the mouth to the stomach in three main stages: o Oral stage ( mouth to oropharynx ) o Pharyngeal stage (oropharynx to esophagus) o Esophageal stage (Esophagus to stomach) Peristalsis and Segmentation Peristalsis is a wave like ripple of the muscle layer of the hollow organ. Is a progressing kind of motility that produces forward movement of ingested material along the GI tract It enables the bolus to move forward along the GIT Segmentation is mixing movement, it occurs when digestive reflexes cause a forward and backward movement with a single segment of the GI tract The Chemical Digestion This consists of:o The saliva. o The gastric juice o The intestinal juice
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The Saliva The saliva is acidic in nature ≈ 6 p H and consists of salivary amylase – Ptyalin, ≈ 1 litre of saliva is produced every day in order to convert carbohydrate to polysaccharides. Secretion is involuntary and can be stimulated by. o Seeing smelling or thinking of food. o The presence of food in the mouth o Nausea These actions stimulate the hypothalamus to send impulses to the salivary glands. The Gastric Juice The gastric juice is acid ≈ 1.5 – 3.5pH, ≈ 1.5 – 2 liters of gastric juice is secreted every day. There are three enzymes in the gastric juice o Pepsin. o This is the main enzyme secreted by chief cells. o The enzyme is produced in an inactive form as pepsinogen, if the ph is ≈ 2, the enzyme convert large protein molecule into smaller peptones. o Gastric lipase. A small amount produced in order to start the digestion of fat o Renin It convert the proteins in milky from casiogen to casein which pepsinogen then can reduce to peptones The gastric juice consists also of mineral salts as sodium, potassium, magnesium, chloride, phosphate and sulphate. Mucus is secreted from the membrane in order to prevent from mechanical injury and lubricate the food. The action of amylase is inhibited by the high acidity in the stomach. The parietal cells produce hydrochloric acid (HCL). o The parietal cells also produce the intrinsic factor. o The enteroendocrine cells produced histamine and serotonin. o They are called local hormones and stimulate to increase secretion of gastric juice and contractions of smooth muscles. The Function of HCL Inhibit the action of amylase. Acts as a protective barrier, killing many potentially microorganisms that enter the stomach with the food. Activate pepsinogen to pepsin. Breaks down proteins, preparing them for assimilation. Secretion of Gastric Juice There is always a small amount of gastric juice present in the stomach, even when it contains no food; this is known as fasting juice. The secretion reaches its maximum level about 1hr after meal then declines to the fasting level after about 4hrs. There are three phases of secretion of gastric juice. o The cephalic phase Thought, sight, smell or taste of food will stimulate the secretion of gastric juice with the help of nervous vagus the 10th cranial nerve. NMT 04102 Anatomy and Physiology NTA Level 4, Semester 1
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This prepares the stomach for food that has been eaten. o The gastric phase. In the pyloric antrum (the lower part of the stomach) begins the production of the hormone gastrin. This production is stimulated by the distension of the stomach by food; also substances as alcohol, coffee or smoking start this process. This process continues as long as food is left in the stomach. The hormone is taken up by the blood stream to give impulses to the central nervous system. With the increased gastrin production an increased production of gastric juice is the end results. o The intestinal phase When an amount of food reach duodenum also this stimulates the production of gastrin but at the same time a hormone complex called enterogastrone in order to slow down the activity of the gastric juice. The decrease speed allows the bile and enzymes from pancreas to empty through the sphincter of oddi by the stimulation of cholecystokinin hormone (gall bladder) and serotonin (pancreas) Absorption and Digestion in the Small and Large Intestines The distended intestine causes production of intestinal juices from intestinal glands. They are situated between the villi and are called the crypts of lieberkuhn or lieberkuhn glands. Until the high acidity of the chyme has been neutralized by the pancreatic juices. It is important to protect the walls of duodenum and this is done by mucus secreted from brunners glands. They are situated in the first few centmetres of duodenum. The intestinal juice contains enzymes activate the hormone secretion and cholecystokinin. Secretion hormone stimulate the pancreas to secrete fluid containing bicarbonate which neutralized the chime if not ulcer occurs. Cholecystokinin causes pancreas to secret enzyme and also the gall bladder to empty the bile. Also the small intestines secrete the enzymes sucrose, maltase, and lactase, the secretion takes place in the epithelial cells covering the villi. The transport through the walls absorption occurs in different ways. Monosaccharide and amino acids are absorbed by active transport and by diffusion. Fatty acids and glycerol diffuses through the walls into the lacteals inside the villi mixed with the lymph it will be transported through the lymphatic system and from the thoracic duct to be empted through the brachiocephalic vein. The absorption of iron, calcium and most vitamins occurs also in the small intestines. Fluid e.g. saliva, gastric juice, pancreatic juice and bile are reabsorbed ≈ 8litre each day. In large intestine most of the water and electrolytes’ are absorbed in the first part. The vitamins B12 and vitamin k needs bacteria before they are absorbed into the blood.
Step 3: Metabolism Food in the Body (50 minutes) Metabolism This is some of all physical and chemical changes that take place within the body. E.g. o The building of tissue – Anabolism NMT 04102 Anatomy and Physiology NTA Level 4, Semester 1
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o The breakdown of tissue – catabolism o The conversion of nutrients into the tissue. o The elimination of waste products For this work the body needs energy in the health adult the balance is kept – energy product equals energy used. The energy is realized from the nutrient by the ATP= Adenosine Triphosphate which help to form the energy reserve. This help us also to keep our body temperature to the best level for chemical reaction A method of stimulating the energy demands in the body is measured in terms of heat. The unit of heat is the calorie, a calorie is that amount of heat required to raise 1< of water, 1°C. 1 calorie = 4.184 joules e.g. o 1g of carbohydrate = 17 kj = 4calorie o 1g of protein = 17kg = 4 calorie o 1g of fat = 38kj = 9 calorie
Basal Metabolic Rate (BMR) This is the rate of the body’s expenditure under basal condition. The BMR can be calculated by estimating the amount of oxygen consumed in a given time The BMR is expressed in calorie (or joules) per square meters of body surface. o Normal BMR = 40 cal/m2 for men 37 cal/m2 for women
Activity: Small Group Discussion ( 30 minutes) DIVIDE students into small manageable groups ASK students to discussion in groups on factors affecting metabolism for 10 minutes ALLOW groups ask students to provide their response for 2 minutes each CLARIFY and summaries by using the contents below Factor Affecting Metabolism Age Exercise requires high energy end ↑ BMR Body temperature ↑BMR ↑ Environmental – tropical climate ↓ BMR. Thyroid hormone increases BMR amount Stimulation of sympathetic system requires ↑ BMR. Drugs e.g. amphetamine, caffeine requires ↑ BMR. Metabolism of Carbohydrate Carbohydrate is absorbed through the villi in the small intestine as monosaccharide. o Glucose o Fructose o Galactose The glucose is stored in the liver the blood glucose level is regulated by hormones. NMT 04102 Anatomy and Physiology NTA Level 4, Semester 1
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After a meal glucose level rises above normal with the aid of hormone insulin the glucose is converted to glycogen and stored in the liver, if the blood sugar level falls the pancreas is stimulated to produce a hormone glucagon which cause them to convert glycogen to glucose. Other hormones are also involved in carbohydrate metabolism e.g. adrenaline glucocorticoids, ACTH and thyroxin.
Metabolism of Protein They are about 20 amino acids known as peptides. 9 are essential we have to get them from food we eat and 11 are non essential the body is able to synthesize them with the help of enzymes transaminases. The metabolism of protein occur in the liver, the amino acids are carried from the liver to the general circulation and are used for:o Building and repair of cells. o Plasma protein e.g. prothrombin (fibrinogen) o Production of gamma globulins of antibodies o Production of enzymes and hormones. The amino acids will be stored in. Liver Other body cells } Amino acid pool The breakdown of amino acids is called deamination, the nitrogen part is split off from the amino acids molecule to form ammonia, the ammonia combines with carbondioxide and form urea which is excreted by the kidneys. In healthy adult this nitrogen balance is kept in the same level all the time. The removal from the “pool” is equal with the addition into it. Metabolism of Fat The body uses fat in the form of fatty acids and glycerol, the fat is a compound containing carbon and hydrogen with very little oxygen. 1g of fat = 9 calories. The end products are energy, carbondioxide and water. Ketone bodies are produced during fat metabolism; they are excreted as acetone leading to acidosis. If the intake of carbohydrate is too poor, the amount of ketone bodies will increase as the body use fat instead of carbohydrate. This state will have a toxic effect on the brain. If you give patient bicarbonate the effect from ketone bodies will be neutralized. Fat is stored in fat deposits e.g. under the skin, in the omentum and around the kidneys.
Step 4: Key Points (5 minutes)
Digestion is the mechanical and chemical breakdown of food into smaller components that are more easily absorbed into the blood strem. Mechanical digestion include mastication, deglutition, peristalsis and segmentation Chemical digestion consists of saliva, gastric juice and intestinal juice
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Step 5: Evaluation (5 minutes)
What is digestion What are the two types of digestion Mention the function of hydrochloric acid What is the effect of ketone bodies in the body
ASK students if they have any comments or need clarification on any points
References
Gray. H (2008) Gray’s Anatomy: anatomical basis for clinical practice. 40th Ed. Elsevier, Patton K. T & Thibodeau G. A. (2007) Anatomy and physiology. (6th Ed). China: Mosby. Richard, L.D., Grays’s Anatomy for students (electronic book) Roby, P. (1993). Anatomy and physiology (6th Ed.). USA: Pearson Custom. Seeley, R. R., Stephens, T. D. & Tate, P. (2003). Anatomy and Physiology. New York: McGraw-Hill Thibodeau, G. A., Patton, K. T. (1999). Anatomy & Physiology. Saint Louis: Mosby, Von Hoffman Press, Inc Waugh, A. & Grant, A. (2006). Ross and Willson Anatomy and physiology in Health and illness. United Kingdom: Churchill Livingstone Elservier.
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Session 16: Structure and Functions of the Lymphatic System Total Session Time: 120 Minutes Prerequisites None Learning Tasks By the end of this session, students are expected to be able to: Identify the parts and organs of the lymphatic system Describe the structure and functions of the lymphatic system Resources Needed Flipcharts, Marker pens and Masking tape Black/white board and chalk/whiteboard markers Anatomical charts, models and atlas LCD and Computer Handout 16.1:Structure of the Lymphatic System SESSION OVERVIEW Step
Time
Activity/Method
Content
1
05 Minutes
Presentation
Presentation of the Session and Learning Tasks
2
40 Minutes
3
65 Minutes
4
05 Minutes
Presentation
Key Points
5
05 Minutes
Presentation
Evaluation
Presentation, Buzz Presentation, Group Discussion
Parts and Organs of the Lymphatic System Structure and Functions of the Lymphatic System
SESSION CONTENT Step 1: Presentation of Session Title and Learning Tasks (5 minutes) READ or ASK students to read the Learning tasks and clarify ASK students if they have any questions before proceeding
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Step 2: Parts and Organs of the Lymphatic System (40 minutes) Activity: Buzzing (10 minutes) TELL the students to pair up and list organs of lymphatic system for 5 minutes ALLOW few student to responses and let other pairs to provide unmentioned responses CLARIFY and summaries by using the information below
The lymphatic system as the circulatory system is responsible to transport substance, one of the major functions is to collect intercellular fluid and return it to the blood. Protein lost from the blood capillaries can easier enter the lymph capillaries because of the large pores. Another major function is to defend the body against the invasion of microorganisms. Some of the cells are phagocytic and other produce antibodies. Below are the parts and organs of the lymphatic system Refer Students to Handout 16.1: Structure of the Lymphatic System
Step 2: Structure and Functions of the Lymphatic System (65 minutes) Activity: Small Group Discussion ( 30 minutes) DIVIDE students into small manageable groups ASK students to discussion in groups on structure and functions of the lymphatic system for 10 minutes ALLOW groups ask students to provide their response for 2 minutes each CLARIFY and summaries by using the contents below Lymph This is a tissue fluid that contains substances of blood except the erythrocytes and platelets. The protein in lymph is less but the amount of lymphocytes is higher because they are formed by the lymphatic tissue Lymph Vessels The lymph vessels starts as sac like blind ended tubes called lymph capillaries. The lymph capillaries are made of a single layer of endothelial cells as the capillaries are. The capillaries drain into larger vessels the collecting ducts which turn into larger vessels – the lymphatic. The lymph vessels have valves that prevent the back flow of the lymph. The transport system is possible because:o The lymph vessel ability to contract by the selves o Tissue fluid pressure NMT 04102 Anatomy and Physiology NTA Level 4, Semester 1
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o Muscle contractions. o Arteries pulsation o Negative pressure during inspiration. Lymph Nodes These are oval or bean- shaped organs that lie often in groups, along the length of lymph vessels. The lymph drains through a number of nodes, usually 8 to 10, before returning to the venous circulation The nodes vary in size, some are as small as a pin lead and the largest are about the size of an a lemon The lymph nodes act as filter for the lymph. They are organized generally in groups. Near the surface we found the lymph nodes in the axilla, groin and neck. The lymph nodes in deeper structures e.g. it drains the abdominal cavity and the organs in the abdominal cavity. The vessels that bring lymph to the nodes are called afferent and those leaving the nodes are efferent vessel. There are many efferent vessels but only one efferent. Refer Students to Handout 16.2: Lymph Node Functions of Lymph Nodes Filtering and phagocytosis o Lymph is filtered by the reticular and lymphoid tissue as it passes through lymph nodes o Particulate matter may include microbes, dead and live phagocytes containing ingested microbes, cells and from malignant tumors, worn out and damaged tissue cells and in haled particles. o Organic material is destroyed in lymph nodes by macrophages and antibodies. Some inorganic included particles cannot be destroyed by phagocytosis. Immune system activation – monitor and attack antigens o In some cases where phagocytosis of microbes is incomplete inflammation and enlargement of the node (lymphadenopathy) occurs. o Proliferation of lymphocytes-activated T and B lymphocytes multiply in lymph nodes and produce antibodies which enter lymph and blood draining the node. Lymphatic Trunks Lymphatic trunks are formed by union of largest collecting ducts Major trunks include: o Paired lumbar, bronchomediastinal, subclavian, and jugular trunks o A single intestinal trunk Lymph is delivered into 1 of 2 large trunks o Right lymphatic duct o Thoracic duct Thoracic Duct Is 40cm long, drains the rest of the body. NMT 04102 Anatomy and Physiology NTA Level 4, Semester 1
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Arises from cisterna chyli and drains rest of body and it empties into the left subclavian vein
The Right Lymphatic Duct It empties the lymphatic in the right subclavian vein. This ducts drains from half of the right arm, head, neck and thorax. The Lacteals The lymph vessels in the small intestines are situated on in each villi. The digested fat is absorbed by these lymph vessels called lacteals. The lymph here has a milky appearance which differs from other parts of the body where it is clear colorless secretion. The fluid here is called chyle Lymphoid Organs Lymphatic system has the following organs Spleen This is formed by reticular and lymphatic tissue and is the largest lymph organ. The spleen lies in the left hypochondriac region of the abdominal cavity between the fundus of the stomach and the diaphragm. It is purplish in color and varies in size in different individuals, but usually about 12cm long, 7cm wide and 2.5cm thick. It weighs about 200g The spleen is slightly oval in shape with the hilum on the lower medial border. The anterior surface is covered with peritoneum; it is enclosed in fibro elastic capsule that dips into the organ forming trabecular. The cellular material, consisting of lymphocytes and macrophages, is called splenic pulp, and it lies between the trabecular. Red pulp is the part suffused with blood and white pulp consists of areas of lymphatic tissue where there are sleeves of lymphocytes and macrophages around blood vessels. The structures entering and leaving the spleen at the hilum are:o Splenic artery o Splenic vein o Lymph vessels (efferent only) o Nerves Functions of Spleen Phagocytosis o Old and abnormal erythrocytes are destroyed in the spleen and the breakdown product, bilirubin and iron, are passed to the liver via the splenic and portal veins. o Other cellular material e.g. Leukocytes, platelets and microbes are phagocytosed in the spleen. Storage of blood. o The spleen contains up to 350mls of blood, and in response to sympathetic stimulation can rapidly return a large part of this volume to the circulation e.g.in case of hemorrhage Immune response. o The spleen contains T- and B lymphocytes, which are activated by the presence of NMT 04102 Anatomy and Physiology NTA Level 4, Semester 1
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antigens e.g. in infection. o Lymphocytes proliferation during serious infection can cause enlargement of the spleen (spleenomegaly) Erythropoiesis. o The spleen and liver are important sites of fetal blood cells production and the spleen can also fulfill this function in adults in times of great need.
Thymus Gland It lies in the upper part of the mediastinum behind the sternum and extends upwards into the root of the neck. It weighs about 10 to 15g at birth and grows until the individual reaches puberty, when it begins to atrophy. Consists of two lobes joined by areolar tissue The lobes consists of irregular branching framework of epithelial cells and lymphocytes Involution of the gland begins in adolescence and with increasing age, the effectiveness of the T – Lymphocyte response to antigens declines Functions of the Thymus Gland Produces mature T – Lymphocytes that can distinguish self tissue from foreign tissue Secrete thymosin a hormone responsible for maturation of the thymus and other lymphoid tissue
Step 4: Key Points (5 minutes)
The lymphatic system as the circulatory system is responsible for transporting substance, one of the major functions is to collect intercellular fluid and return it to the blood. Lymph is a fluid tissue that contains substances of blood except the erythrocytes and platelets. The protein in lymph is less but the amount of lymphocytes is higher because they are formed by the lymphatic tissue The lymph nodes act as filter for the lymph Defend the body against the invasion of microorganisms. Some of the cells are phagocytic and other produce antibodies.
Step 5: Evaluation (05 minutes)
What is a lymph Mention the functions of the spleen What are the functions of the lymph nodes
ASK students if they have any comments or need clarification on any points
References
Gray. H (2008) Gray’s Anatomy: anatomical basis for clinical practice. 40th Ed. Elsevier, Patton, K. T & Thibodeau, G. A. (2007) Anatomy and physiology. (6th ed). China: Mosby. Roby, P. (1993). Anatomy and physiology. (6th ed.). USA: Pearson Custom.
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Seeley, R. R., Stephens, T. D. & Tate, P. (2003). Anatomy and Physiology. New York: McGraw-Hill Thibodeau, G. A., Patton, K. T. (1999). Anatomy & Physiology. Saint Louis: Mosby, Von Hoffman Press, Inc Waugh, A. & Grant, A. (2006). Ross and Willson Anatomy and physiology in Health and illness. United Kingdom: Churchill Livingstone Elservier.
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Handout 16.1:Structure of the Lymphatic System
Source: www.studentconsult.com
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Handout 16.2: Lymph Node
Source: www.studentconsult.com
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Session 17: Structure and Functions of the Blood Total Session Time: 120 Minutes Prerequisites None Learning Tasks By the end of this session, students are expected to be able to: Identify the organs of the Circulatory system Describe the structure and functions of the blood Resources Needed Flipcharts, Marker pens and Masking tape Black/white board and chalk/whiteboard markers Anatomical charts, models and atlas LCD and Computer Handout 17.1: Composition of Blood Handout 17.2: Blood Groups Handout 17.3: Additional Information About Blood Groups SESSION OVERVIEW Step
Time
Activity/Method
Content
1
05 Minutes
Presentation
2
30 Minutes
3
75 Minutes
4
05 Minutes
Presentation
Key Points
5
05 Minutes
Presentation
Evaluation
Presentation of Session Title and Learning Tasks
Presentation, Brainstorm Presentation, Group Discussion
Organs of the Circulatory System Structure and Functions of the Blood
SESSION CONTENT Step 1: Presentation of Session Title and Learning Tasks (5 minutes) READ or ASK students to read the Learning tasks and clarify ASK students if they have any questions before proceeding
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Step 2: Organs of the Circulatory System (30 minutes) Activity: Brainstorming (05 minutes) ASK the students to brainstorm on organs of the circulatory system for 2 minutes ALLOW few students to respond and let other pairs to provide unmentioned responses WRITE their response on the flip chart/board CLARIFY and summaries by using the information below The Circulatory System Is the part of internal transport system The circulatory system consists of o Blood o Blood vessels o Heart.
Step 3: Structure and Functions of the Blood (75minutes) Activity: Small Group Discussion ( 30 minutes) DIVIDE students into small manageable groups ASK students to discussion in groups on structure and functions of the blood for 10 minutes ALLOW groups ask students to provide their response for 2 minutes each CLARIFY and summaries by using the contents below Blood Is a fluid connective tissue. It provides one of the means of communication between the cells of different parts of the body and the external environment. Blood makes up about 7% of body weight (about 5.6 liters of blood in a 70 kg man. This proportion is less in women and considerably greater in children gradually decreasing until the adult level is reached. Functions of the Blood It transport oxygen and nutrients and take away waste material to the excretory organs e.g. Kidney. Carries hormones. Carries antibodies to protect against infection. Carries heat from more active tissues to less- keep the body temperature.
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Composition of Blood Blood is composed of a straw colored transparent fluid called Plasma (55%) and different cells (45%) If you take away the blood the clotting factor and the cells from blood you will have serum left the blood clotting factor is fibrinogen. Plasma The plasma consists of 90-92% water and dissolved substances including Plasma proteins o This makes up about 7% of plasma, are normally retained within the blood because they are two big to escape through the capillary pore into the tissues. o They are largely responsible for creating the osmotic pressure of blood (normally 25 mm Hg) which keeps plasma fluid within the circulation. o If plasma protein levels fall, because of either reduced production or loss from the blood vessels, osmotic pressure is also reduced and fluid moves into the tissues and body cavities and cause OEDEMA. The plasma proteins contain. o Albumin These are formed in the liver; their main function is to maintain a normal plasma osmotic pressure. o Globulins Most are formed in the liver and the most important is immune- globulins forms antibodies as a protection against infection. Another name is Gamma globulin. o Clotting factors These are substances essential for coagulation of blood they are 12 factors e.g. prothrombin factor 2 and fibrinogen factor 1. o Mineral Salts These are involved in a wide variety of activities including Cell formation Contraction of muscles Transmission of verve impulses. Maintaining the( PH 7.4) in blood in health the blood is slightly alkaline, These mineral salts are present in the plasma in the form of ions Na+ cl- HCO-3 o Nutrients Food is digested in the alimentary tract and the resultant nutrients are taken up by the blood stream. Amino acids – Protein. Fatty acids- Fat Vitamins and mineral salts Glycerol Monosaccharaides. o Waste material Urea Cretinine Uric acid Carbon dioxide released by all cells is excreted through the lungs. o Gases Oxygen carbon dioxide and nitrogen are transported round the body in solution in plasma. NMT 04102 Anatomy and Physiology NTA Level 4, Semester 1
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Cellular Content of Blood There are the three types of blood cells. o Red blood cells or erythrocyte comprises 40- 45% of the total blood volume (4.2 – 6.2 mill/microliter). o Platelets or Thrombocytes 25, 0000- 350000. o White blood cells – leucocytes 5000 – 9000 Erythrocytes (Red Blood Cells) The red blood cells are developed from stem cells in the end of the long bones, flat and irregular bones. In fetus the blood cells are formed even in liver, spleen, thymus and lymph nodes. The cells are flexible in shape and they are able to pass through the capillaries which are wider than the size of the cell. The cell has no any nucleus and can therefore not reproduce themselves They live~ 120 days and the production has to be in balance with the destruction. The main component hemoglobin consists of a large protein molecule called globin into which 4 molecules of those can carry one molecule of O2 – for this attachment iron is necessary. A small amount of CO2 is also carried away by the red blood cells but most of it is carried away with plasma. The process of development takes about 7 days and is called Erythropoiesis or Hematopoiesis. Essential Factor for Blood Formation Intrinsic factor o Vitamin B12 - cyanocabalamin cyno means- Blue o B12 is stored in the liver. o Absorption of vitamin B12 depends on glycoproteins called intrinsic factor secreted by parietal cells it is possible to produce it synthetically and given as an injection. Extrinsic Factors o Folic acid This is also necessary for the developing of red blood cells, present in yeast, green vegetables, liver and kidney. o Iron Transferrin- a protein in plasma carries iron to the bone marrow where it will be used or stored in the liver in the form of ferin A lack of iron will cause anemia. o Vitamin C A small amount of vitamin c is necessary for the blood formation. Control of Erythropoiesis The number of red blood cells remains fairly constant, which means that the bone marrow produces erythrocytes at the rate at which they are destroyed. This is due to homeostatic negative feedback mechanism. The primary stimulus to increased Erythropoiesis is hypoxia i.e. deficient oxygen supply to body cells. Hypoxia increases erythrocyte formation by stimulating the production of the hormone erythropoietin mainly by the kidneys. NMT 04102 Anatomy and Physiology NTA Level 4, Semester 1
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Destruction of Erythrocytes The life span of erythrocytes is about 120 days and their break down, or hemolysis, is carried out by phagocytes reticuloendotherial cells. These cells are found in many tissues but the main sites of hemolytic are the spleen, bone marrow and lives. Blood Group The membrane of the red blood cells contains glycoproteins and some of them behave like antigens. These antigens can produce another protein known as antibodies; those antibodies are acting against with specific antigens. When produced they circulate in blood as a parts of gamma globulins. The antigens that are formed on the erythrocytes decide which blood group a person will have. If mixing with wrong blood group the antigen and antibodies cause a transfusion reaction. This reaction agglutinate the erythrocytes therefore the antigens sometimes are called agglutinogens. The blood groups are based on the presence of antigens A or antigens B. If a Person does not have any antigen the person have blood group O About 55% of the population has either A- type antigens (blood group A) or B type Antigens (blood group B) or both (blood group AB). The remaining 45% have neither A nor B type antigens (Blood group O). Blood group AB people makes neither anti A nor anti B antibodies they are known as universal recipients Transfusion of either type A or type B blood into these individuals is safer since there are no antibodies to react with them, Group O people have neither A nor B antigens on their red cells membranes and their blood may be safely transfused into A, B, AB or O types, Group O are known as the universal donor. The following are the blood groups. o Group A has antigen A antibody B o Group B has antigen B antibody A o Group A has antigen A, B antibody none o Group O has no antigen but has both antibodies A person’s blood group does not consists of the agglutinating antibody, the blood has to be cross- matched first before blood transfusion, Cross matching involves mixing a sample of recipient’s cells with donor plasma and donor cells with recipient’s plasma. Individuals are transfused with blood of the same group o If they are given blood from an individual of a different blood type, with a different type of antigen on the red cells, their immune system will mount an attack upon them and destroy the transfused cells.
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This is the basic of the transfusion reaction; the blood types, the donor and the recipient are incompatible. Donor plasma
Recipients
Donors cells
Recipients cells.
There are also other antigens in the blood e.g. M, N, KE (Duffy Lewis etc.) . They can causes agglutination even if it the same blood group. Therefore: o Group A give blood to AB and A o Group B give blood to AB and B o Group AB give blood to AB o Group O give blood to all blood groups. Group A receives blood from – A and O Group B receives blood from –B and O Group AB receives blood from all blood groups Group O receiver blood from group O only.
Rhesus Factor This system can also cause agglutination in the blood. As the system first was discovered in monkeys (Rhesus monkeys) the factor was given the abbreviation About 80- 85% of the population has this antigen on the cell membrane as with the blood group antigen. We call this antigen Rh+, the remaining 15% have no Rh antigen they are called Rh-. If a person with Rh- blood is given Rh+ blood the body starts to produce antibodies, if the same patient is given the wrong blood a second time agglutination will occur. The same thing will occur during the pregnancy, if the mother is Rh- and the chilled is Rh+ the antigens from the child will enter the mothers blood system and antibodies will be formed. To the next pregnancy the mother has antibodies; these antibodies are crossing the placenta and damage the blood of the fetus. o Group O = 45% o Group A= 40% o Group B = 10% o Group AB = 5% Thrombocytes or Platelets These are very small without nucleus (non-nucleated), they are derived from the cytoplasm of Megakaryocytes in red bone marrow. They live for 10 days and are then destroyed by macrophages mainly in the spleen They contain a variety of substance that promote blood clotting which causes homeostasis (Cessation of bleeding)
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Hemeostasis When a blood vessel is damaged, loss of blood is stopped and clotting occurs in a series of overlapping processes in which platelet play a vital part there are three processes which are involved. Blood vessel spasm (Vasoconstriction) o The blood vessels are stimulated to contract by nerve impulses from the pain receptors in the damaged area, o Other chemicals that cause vasoconstriction e.g. thromboxane are released by the damaged vessel itself Formation of a platelet drug o This occurs immediately after the tissue has been damaged. o The thrombocytes get stuck and adhere; some enzymes ADP (Adenosine Triphosphate) increase the stickiness of the platelets (positive feedback). o The platelet release other substances e.g. serotonin which stimulate to further constriction of the blood vessels. Coagulation of the blood around the damaged area. o This is a complex mechanism (process) that also involves a positive feedback system and only a few stages are included here. o The factors involved are listed in table 4.3 page 68 The extrinsic mechanism The intrinsic mechanism The extrinsic mechanism o For this mechanism factors (x) is necessary. o The damaged area release lipoprotein- thromboplastic with the help of factor x and some irons coagulation takes place. The intrinsic mechanism. o The rupture inside the blood vessels activate factor (x) Prothrombin that are present in blood and stored by the liver because thrombin Vitamin K is necessary for Synthesizing of prothrombin A inactive substance – a protein Fibrinogen will now be activated and become fibrin. Fibrin forms threads and a clot is formed. Factor X + Prothrombin + vitamin .K. Thrombin
Fibrinogen
Fibrin
clot.
Leukocytes These cells have an important function in defending the body against microbes and other foreign. Leukocytes are the largest blood cells and they account for about 1% of the blood volume. o They contain nuclei and some have granules in their cytoplasm. o There are two main types. Granulocytes or polymorph nuclear cells. NMT 04102 Anatomy and Physiology NTA Level 4, Semester 1
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Agranulocytes, monocytes and lymphocytes. o They are developed from stem cells called myeloblasts. Main Functions of the Leukocytes To protect the body against invasion of bacteria. To remove the dead or injured tissue. o If bacteria enter the body the leukocytes surround and engulf them. o If the toxin from the bacteria is strong enough it kills the leukocytes and seen as pus. If the bacteria have been killed the leukocytes remove the tissue which has been damaged. Granulocytes or Poplymophonuclea Cells There are three types o Neutrophils o Eosinophil o Basophils. Neutrophills Their main function is to o Protect the body against any foreign material that gains entry to the body, mainly microbes o Remove waste materials e.g. cell debris. o They increased in large number in case of. Metabolic disorders Leukemia. Heavy smoking. Oral contraception. o If you acquire a viral infection the neutrophils start to produce a substance called interferon. o This protein reduces the spread of the infection. o Now days it is produced synthetically in form of Injection i.e. interferon injection is given to a patient with cancer or severe blood diseases. Eosinophills These are increased in number in case of asthma, Hay fever and parasitic worms. Its main functions are o They neutralize histamine which occurs in context with allergic condition. o Transport plasminogen the stage before plasmin. o They are protecting the body against parasites. Basophils They are closely associated with allergic reactions contain cytoplasmic granules packed with heparin – an anticoagulant produced in the liver it is released by the help of basophiles Also it is associated with histamine – an inflammatory agent and other substances that promote inflammation.
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These are the largest of all the leucocytes. It contains one nucleus, They are working into:o Blood (phagocytic) o Tissue (macrophages) The number increases in case of o Microbial infection. o Collagen diseases (diseases in the connective tissue e.g. rheumatic fever, Arthritis).
Lymphocytes They protect the body against foreign material they are smaller than monocytes and have large nuclei they circulate in blood and are present in great number in lymphatic tissue such as lymph nodes and spleen. There are two types of lymphocytes:o T- lymphocytes produced in thymus o B- Lymphocytes.
Refer students to: Handout 17.1: Composition of Blood Handout 17.2: Blood Groups Handout 17.3: Additional Information about Blood Groups
Step 4: Key Point (5 minutes)
Blood is a fluid connective tissue It transport oxygen and nutrients and take away waste material to the excretory organs e.g. Kidney The main constituents of blood are Plasma and packed cells There are four blood groups, A, B, AB, and O To be given blood the recipient must be compatible with the blood donor to avoid agglutination recipient blood
Step 5: Evaluation (5 minutes)
What are the functions of blood Why do people react when give blood transfusion What are the four groups of blood
ASK students if they have any comments or need clarification on any points
References
Gray. H (2008) Gray’s Anatomy: anatomical basis for clinical practice. 40th Ed. Elsevier, Patton, K. T & Thibodeau G. A. (2007) Anatomy and physiology. (6th ed). China: Mosby. Roby, P. (1993). Anatomy and physiology (6th Ed.). USA: Pearson Custom. Seeley, R. R., Stephens, T. D. & Tate, P. (2003). Anatomy and Physiology. New York: McGraw-Hill
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Thibodeau, G. A., Patton, K. T. (1999). Anatomy & Physiology. Saint Louis: Mosby, Von Hoffman Press, Inc Waugh, A. & Grant, A. (2006). Ross and Willson Anatomy and physiology in Health and illness. United Kingdom: Churchill Livingstone Elservier.
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Handout 17.1: Composition of Blood
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Handout 17.2: Blood Groups
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Handout 17.3: Additional Information about Blood Groups
Almost always, an individual has the same blood group for life; but very rarely an individual's blood type changes through addition or suppression of an antigen in infection, malignancy or autoimmune disease. An example of this rare phenomenon is the case of an Australian citizen, whose blood group changed after a liver transplant. Another more common cause in blood type change is a bone marrow transplant. If a person receives a bone marrow from someone who is a different ABO type (ex. a type A patient receives a type O bone marrow), the patient's blood type will eventually convert to the donor's type. Some blood types are associated with inheritance of other diseases. Certain blood types may affect susceptibility to infections, an example being the resistance to specific malaria species seen in individuals lacking the Duffy antigen. The Duffy antigen is a protein located on the surface of red blood cells and is named after the patient in which it was discovered. On erythrocytes the Duffy antigen acts as a receptor for invasion by the human malarial parasites Plasmodium vivax. Duffy negative individuals whose erythrocytes do not express the receptor are believed to be resistant to merozoite invasion A connection has been found between HIV susceptibility and the Duffy antigen expression. The presence of the Duffy antigen receptor appears to increase the susceptibility to infection by HIV. After birth an infant gut becomes colonized with normal floras which express these A-like and B-like antigens, causing the immune system to make antibodies to those antigens that the red cells do not possess. So, people who are blood type A will have Anti-B, blood type B will have Anti-A, blood type O will have both Anti-A and Anti-B, and blood type AB will have neither. Because of these so called "naturally occurring" and expected antibodies, it is important to correctly determine a patient's blood type prior to transfusion of any blood component.
Rhesus Factor Cross-matching for the RhD antigen is extremely important, because the RhD antigen is immunogenic, meaning that a person who is RhD negative is very likely to make AntiRhD when exposed to the RhD antigen (perhaps through either transfusion or pregnancy). Once an individual is sensitised to RhD antigens their blood will contain RhD IgG antibodies which can bind to RhD positive RBCs and may cross the placenta. A RhD negative patient who does not have any anti-RhD antibodies (never being previously sensitized to RhD positive RBCs) can receive a transfusion of RhD positive blood once, but this would cause sensitization to the RhD antigen, and a female patient would become at risk for hemolytic disease of the newborn RhD positive blood should never be given to RhD negative women of childbearing age or to patients with RhD antibodies. In extreme circumstances, such as for a major bleed when stocks of RhD negative blood units are very low at the blood bank, RhD positive blood might be given to RhD negative NMT 04102 Anatomy and Physiology NTA Level 4, Semester 1
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females above child-bearing age or to Rh negative males, providing that they did not have anti-RhD antibodies, RhD positive patients do not react to RhD negative blood.
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Session 18: Structure and Functions of the Blood Vessels and the Heart Total Session Time: 120 Minutes Prerequisites None Learning Tasks By the end of this session, students are expected to be able to: Describe the structure and functions of the blood vessels Describe the structure and functions of the Heart Resources Needed Flipcharts, Marker pens and Masking tape Black/white board and chalk/whiteboard markers Anatomical charts Anatomical models and atlas LCD and Computer Handout 18.1 Structural Features of Artery and Vein Handout 18.2 Types of Capillaries Handout 18.3 Internal Structure of Vein Handout 18.4: Systemic and Pulmonary Circulation Handout 18.5: Clotting Mechanism Handout 18.6: Structural of the heart Handout 18.7: Systole and Diastole Handout 18.8: Phases of cardiac cycle SESSION OVERVIEW Step
Time
Activity/Method
Session Content
1
05 Minutes
Presentation
Presentation of the Session and Learning Tasks
2
50 Minutes
3
55 Minutes
4
05 Minutes
Presentation
Key Points
5
05 Minutes
Presentation
Evaluation
Presentation, Group Discussion Presentation Group Discussion
Structure and Functions of the Blood Vessels Structure and Functions of the Heart
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ASK students if they have any questions before proceeding
Step 2: Structure and Functions of the Blood Vessels (50 minutes) Activity: Small Group Discussion ( 30 minutes) DIVIDE students into small manageable groups ASK students to discussion in groups on functions of the blood vessel 10 minutes ALLOW groups ask students to provide their response for 2 minutes each CLARIFY and summaries by using the contents below Blood Vessels Origin of blood vessels, o The blood vessels originate from the mesoderm the middle layer that develops 3 weeks after fertilization. o The early development of blood vessels is essential to survive as the ovum contains very little stored food material. Structure of the Blood Vessels Arteries The artery carries the blood from the heart to the capillaries, the walls are thick and consist of three layers:o The outer layer or Tunica Consists of fibrous connective adventitia tissue and smooth muscle cells large arteries are supplied with blood vessels that nourish the thick walls, those blood vessels are called vasa vasorum o The middle layer Tunica media of elastic connective tissue and smooth muscles. o The inner layer Tunica internal or intimae, Consists of a single layer of epithelium cells called Endothelium This endothelium also lines the heart and lymph vessels. The walls of a muscular artery can contract, vasoconstrict and relax vasodilate. By this mechanism the pressure is kept in a constant level. Many tissue get blood supply from more than one artery and bronchi. The connection between two branches is called anastomosis. These anastomosis help to assure that a tissue will receive blood even if one of the vessels is blocked The arteries become arterioles and carry blood to the smallest part of all blood vessels the capillaries. In the function the pre capillary sphincters control the entry of blood into the capillary.
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Capillaries The diameter of the capillary is the same of the red blood cells. The capillary net work save that every cell has a capillary passing close to the tissue. The walls of the capillary consist of the one single layer of endothelium. The function of the capillary is to exchange materials between the blood and the cell, large molecules and the red blood cells don’t normally pass but the white blood cells are able to:-pass. Specialized capillaries can be found in certain organ in the body e.g. Kidney has the capillaries of small holes in order to filtrate the blood to form urine. In liver the capillaries are enlarged and called sinusoids. They are lived with phagocyte cells that remove foreign materials. The circulation is slow through the sinusoids so there is time for phagocytic action. Veins The veins contain deoxygenated blood that goes back to the heart from the capillaries tiny venules unit to form vein. The vein also consists of three layers but the walls are much thinner. They have less amount elastic tissue as they don’t have to expand as the arteries. Two factors that help the blood in the veins to move are:o Muscle contraction and respiration o Valves contraction by a fold of tunica intima. As the arteries have their sinus also the vein has sinuses, they can be found in the brain, spleen, liver and the heart. Circulation of the Blood Although circulations of blood round the body are continuous it is convenient to describe it in two parts. Pulmonary circulation Systemic or general circulation. Pulmonary Circulation This consists of circulation of blood from the right ventricle of the heart to the lungs and back to the left atrium of the lungs CO2 is excreted and O2 is absorbed. The pulmonary artery or trunk carrying deoxygenated blood from the upper part of the right ventricle of the heart. Passes up wards and divides into left and the right ventricle of the heart. As it passes upward it divides into left and right pulmonary arteries at the level of the 5th thoracic vertebra, the left pulmonary artery runs to the root of the left lung and the right pulmonary artery passes to the root of the right lung. Within the lungs these arteries divide and subdivide into smaller arteries, arterioles and capillaries. The interchange of gases takes place between capillary blood and air in the alveoli of the lungs. In each lug the capillaries containing oxygenated blood join up and eventually form two veins. Two pulmonary veins leave each lung, returning oxygenated blood to the left atrium of the heart. During atria systole this blood passes into the left ventricle, and during ventricular systole it is forced into the aorta, the first artery of the general circulation. NMT 04102 Anatomy and Physiology NTA Level 4, Semester 1
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Systemic or General Circulation The blood pumped out from the left ventricle is carried by the branches of the aorta around the body and is returned to the right atrium of the heart by the superior and inferior venacava. The circulation of blood to the different parts of the body will be described in the order in which their arteries branch off the aorta The Major Arteries in the Systemic Circulation The Aorta o Starts upwards from the left ventricle in the heart. o This part is called ascending aorta. o The vessels continue with the aortic arch- which is curved backwards to the right. o Finally it leaves down wards and is now called descenching aorta. o The aorta pass through the diaphragm through a hole called the aortic hiatus at the level of the 12th thoracic vertebrae, at the level of the 4th lumbar vertebra the aortic divide into right and left common iliac artery. o The right and left coronary arteries supplies the heart with blood, the left common carotid artery arise directly from aorta – it supply the left side of the neck and the head. o The third large artery that leaves the aortic valve is the brachiocephalic artery, it passes upwards about 5-7cm from where it divides into the right subclavian artery which supply the right shoulder and arm and the right common carotid artery supplies the right side of the head and neck. o From the right and left subclavian arteries also the vertebral arteries leave the thoracic aorta gives off paired branches as: Brachial arteries. Esophageal arteries. Intercoastal arteries. The abdominal aorta and its branches o After aorta passed through the aortic hilus the phrenic arteries leave and give or supply to the diaphragm o The great coeliac artery branches into the gastric arteries which supply the stomach, the spleen and the common hepatic artery that supply the liver gall bladder and parts of the stomach and pancreas. o The superior mesenteric artery will supply blood to the small intestines and parts of colon. o The right and left renal artery give blood supply to the kidney and branches from this supply the adrenal glands. o The suprarenal arteries, gonad arteries give blood supply to testes in male and to the ovaries in female. o The inferior mesenteric artery supplies parts of colon and also rectum. o The common iliac artery divides into external iliac artery and internal iliac artery and internal iliac arteries the external part supply the hip and leg and the internal iliac artery supply the urinary bladder, muscles of the buttocks, uterus and prostate gland. The veins o The two largest veins carry blood to the right atrium in the heart from different areas, o The superior venacava collects blood from the upper parts head, neck and upper limbs, the inferior venacava receives blood from the rest of the body. o The external jugular vein collects the blood from the brain. o This vein empty the blood in the subclavian vein NMT 04102 Anatomy and Physiology NTA Level 4, Semester 1
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o The deeper internal jugular vein collects blood from sinuses. o The sinuses are formed by layer of dura mater the outer protective covering of the brain. Also the internal jugular vein empties into the subclavian vein. o After entering hear the blood continue into the brachiocephalic vein and continues in the superior venacava which enter the right atrium o The veins of the upper limbs these are deeper and more superficial vein that convey blood to the heart. o The cephalic vein starts at the back of the fore arm and in front of the elbow; the median cubital vein gives off a branch to join the basilic vein and the right brachial vein. o The cephalic vein continues at the lateral aspect of the arm. o The median vein starts at the palmer side of the hand and join the basilic vein the deeper vein – the axillary vein, the radial vein and the ulna vein follows the arteries with the same name Portal circulation. o The individual veins from the stomach, spleen and intestines unit to form one large vein. o The portal vein. o In the liver this vein is split up again in capillaries and forms a second set of capillaries. o These capillaries unit again and form the three major hepatic veins which leave the liver and enter venacava just before it enters in the thoracic cavity. o The hepatic artery supplies with oxygen and takes no part in the portal circulation. o These veins are: Splenic vein Inferior mesenteric vein Superior mesenteric vein Gastric veins Cystic vein. Refer Students to: Handout 18.1: Structural Features of Artery and Vein Handout 18.2: Types of Capillaries Handout 18.3: Internal Structure of Vein Handout 18.4: Systemic and Pulmonary Circulation
Step 3: Structure and Function of the Heart (55 minutes) Activity: Small Group Discussion (20 minutes) DIVIDE students into small manageable groups ASK students to discuss in groups the structure and functions of the heart for 5 minutes ALLOW students to provide their responses in groups for 2 minutes each CLARIFY and summaries by using the information below
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The Heart The heart is a roughly cone shaped hollow muscular organ. It is about 10cm long and is about the size of the owners fist It weighs about 225g in women and is heaver in men, about 310g. It is located in the thoracic cavity in the mediastinum between the lungs immediately above the diaphragm to the left side of sternum. Its apex is pointing down wards and the base is at the level of the second rib. The right and left part consists of two chambers an upper part with thin walls called ventricle or pumping chambers. The right area pumps blood into the pulmonary circulation and the left area into the systemic circulation. The two areas are divided by a wall called the septum. Structure of the Heart The heart consists of three layers of tissue pericardium, myocardium and endocardium Pericardium, o Is a two layer sac made from serous membrane. o The parietal layer is the outer layer while o The Inner layer is the visceral layer also called pericardium. o The serous membrane cells. o It secretes serous fluid into the space between the visceral and parietal layers which allows smooth movement between them when the heart beats. Myocardium. o The muscle layer of the heart is not under the control of our will (involuntary) o Each fiber has a cell with nucleus and they are connected with intercalated discs, o The thickness of this layer varies, the atrium has the thinnest myocardium and the left ventricle is the thickest according to their work. Endocardium o This consists of a single layer of endothelial cells continuing with the lining of the blood vessels, this layer forms the valves with the cusps inside the heart. Flow of Blood through the Heart The two largest veins of the body the superior and inferior venacavae, empty their contents into the right atrium. When the deoxygenated blood enters the right atrium the first valve open up the right atrioventricular valve or the tricuspid valve). The blood has now entered the right ventricle and will continue through the pulmonary valve into the pulmonary artery. The oxygenated blood is returning from the lungs in the pulmonary veins into the left atrium and continues through the left atrioventricular valve also called mitralis valve. The mitral valve has two cusps compared with the three in tricuspid valve. The blood is now inside the left ventricle and continues through the aortic valve where it will be pumped out into aorta. This valve consists of three cusps. The construction of valves prevents the back flow of blood. A tendon the chordae tendinae prevent the valves from opening up wards, they are attached to the papillary muscles in the lower parts of the ventricles. When both atria contract the tricuspid and mitral valve open up when both ventricles contract the pulmonary and the aortic valves open up. NMT 04102 Anatomy and Physiology NTA Level 4, Semester 1
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Blood Supply to the Heart Arterial supply, o The heart is supplied with arterial blood by the right and left coronary arteries which branch from the aorta immediately distal to the aortic valve o The coronary artery receives about 5% of the blood pumped from the heart, although the heart comprises a small proportion of body weight. Venous drainage o Most of the venous blood is collected into several small veins that join to form the coronary sinus which opens into the right atrium Conducting System of the Heart The heart has an intrinsic system whereby the cardiac muscles are automatically stimulated to contract without the need for a nerve supply from the brain. However the intrinsic system can be stimulated or depressed by nerve impulses initiated in the brain and by circulating chemicals including hormones. There are small groups of specialized neuromuscular cells which initiate and conduct impulses causing coordinated and synchronized contraction of the heart muscle and these are:o Sino atrial node (SA- node) o Atrio ventricular node (AV – node) o Atrioventricular bundle AV- bundle or bundle of his ) o Purkinje fibers. Sinoatrial node (SA- node) o This is the normal cardiac pace maker. I lie in the walls of openings of the superior venacava entering into the right ventricle. o The electrical impulse takes place because of the cells depolarization and repolarization. o The exchange through the semi permeable membrane in the cells of sodium and potassium ions, cause this electrical impulse. o The SA- node intricate the impulses towards the atria. The Atrioventricular mode (AV- node) o This small mass of neuromuscular tissue is situated in the wall of the atrial septum near the atrioventricular valves. o The AV- node is stimulated by the impulses from the SA- node and transferred when the contractions of the atria are completed. Atrioventricular bundle or bundle of his o Those specialized fibres originate from the AV- node. o This is the only direct communication between the atria and ventricles the bundle of his divides into the right and left branches. Purkinjes fibers. o The bundle of his ends up into purkinjes fibres which cause the ventricles to contract and empty the blood into aorta and the pulmonary arteries. o The wave of contraction starts from apex and continues back to the base of the heart. Nerve Supply to the Heart The heart is able to beat even if there is no supply from the nervous system, but the autonomic nervous system controls the rate of the heart beat.
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The cardiac center in medulla oblongata gives impulses either to the sympathetic system to quicken the heart beat or to the parasympathetic system to decrease the force and rate in order to keep the balance The 10th cranial nerves (vagus nerve) gives impulses to SA- node and the AV- node
Cardiac Cycle The function of the heart is to maintain a constant circulation of blood throughout the body. The heart acts as a pump and its action consists of a series of events known as the Cardiac cycle. The cardiac cycle consists of one heart beat or one cycle of counteraction and relaxations it lasts about 0.8 of a second and consists of. o Atria systole – contraction of the atria. o Ventricular systole – contraction of the ventricles. o Complete cardiac cycle- relaxation of the atria and ventricles. The contraction of both atriums lasts about 0.1 sec atria systole the ventricles have now got impulse to contract and this ventricular systole takes 0.3 sec. The complete cycle of cardiac lasts 0.8 sec if beats / min. is 60 to 80, (0.4+0.3+0.1 sec = 0.8sec ) Refer Students to: Handout 18.6: Structural of the Heart Handout 18.7: Systole and Diastole Handout 18.8: Phases of Cardiac Cycle
Step 4: Key Points (5minutes)
The three types of blood vessels are the arteries, veins and capillaries The two largest veins of the body the superior and inferior venacava, empty their contents into the right atrium. All arteries carries oxygenated blood except the pulmonary artery All veins carry deoxygenated blood except the pulmonary vein
Step 5: Evaluation (5 minutes)
Mention the main blood vessels Differentiate between pulmonary and systemic circulation What are the functions of the heart
ASK students if they have any comments or need clarification on any points
References
Seeley, R. R., Stephens, T. D., & Tate, P. (2003) Anatomy and Physiology. New York: McGraw-Hill Shier, A., Butler, J. & Lewis, R. (2004). Hole’s Human Anatomy & Physiology. New York: McGraw-Hill
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Standring, S. (2008). Grays’s Anatomy The anatomical basis of clinical practice. United Kingdom: Churchill Livingstone Elservier. Thibodeau, G. A. & Patton, K. T. (1999). Anatomy & Physiology. Saint Louis: Mosby, Von Hoffman Press, Inc Waugh, A. & Grant, A. (2006). Ross and Willson Anatomy and physiology in Health and illness. United Kingdom: Churchill Livingstone Elservier.
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Handout 18.1: Structural Features of Artery and Vein
Source Grays Anatomy, 2005
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Handout 18.2: Types of Capillaries
Fenestrated capillaries
1) Continuous capillaries have a close connection between adjacent cells and will permit only small molecules < 10nm in diameter to cross. Continuous capillaries surround muscle, skin lungs, adipose tissue CNS, retina and mammary glands.
2) Fenestrated capillaries contain 'windows' that offer easy passage to larger molecules (10-100nm) and are found around the kidneys, pancreas, gallbladder and intestine.
3) Discontinuous have wide gaps between the cells and will allow practically anything (even cells) across. Permeable to substances <600-300nm Discontinuous capillaries surround the liver, spleen, ovaries and some endocrine glands.
Source: Peter M. Smith 1998
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Handout 18.3 Internal Structure of Vein
Source: Peter M. Smith 1998
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Handout 18.4: Systemic and Pulmonary Circulation
Source Elsevier Ltd, 2005
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Handout 18.5: Clotting Mechanism
The clotting mechanism responsible for the formation of fibrin involves a cascade of reactions in which inactive enzymes are activated, and the activated enzymes in turn activate other inactive enzymes. The fundamental reaction in the clotting of blood is conversion of the soluble plasma protein fibrinogen to insoluble fibrin. The process involves the release of two pairs of polypeptides from each fibrinogen molecule. The remaining portion, fibrin monomer, then polymerizes with other monomer molecules to form fibrin. The fibrin is initially a loose mesh of interlacing strands. It is converted by the formation of covalent crosslinkages to a dense, tight aggregate (stabilization). This latter reaction is catalyzed by activated factor XIII and requires Ca2+. Figure 1
Source: McGraw-Hill Companies, Inc 2006
The conversion of fibrinogen to fibrin is catalyzed by thrombin. Thrombin is a serine protease that is formed from its circulating precursor, prothrombin, by the action of activated factor X. Factor X can be activated by reactions in either of two systems, an intrinsic and an extrinsic system.
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The initial reaction in the intrinsic system is conversion of inactive factor XII to active factor XII (XIIa). Activation in vivo occurs when blood is exposed to the collagen fibers underlying the endothelium in the blood vessels. Active factor XII then activates factor XI, and active factor XI activates factor IX. Activated factor IX forms a complex with active factor VIII, which is activated when it is separated from von Willebrand factor. The complex of IXa and VIIIa activate factor X. Phospholipids from aggregated platelets (PL) and Ca2+ are necessary for full activation of factor X. The extrinsic system is triggered by the release of tissue thromboplastin, a protein– phospholipid mixture that activates factor VII. The tissue thromboplastin and factor VII activate factors IX and X. In the presence of PL, Ca2+, and factor V, activated factor X catalyzes the conversion of prothrombin to thrombin. The extrinsic pathway is inhibited by a tissue factor pathway inhibitor that forms a quaternary structure with TPL, factor VIIa, and factor Xa.
Anticlotting Mechanisms The tendency of blood to clot is balanced in vivo by limiting reactions that tend to prevent clotting inside the blood vessels and to break down any clots that do form. These reactions include the interaction between the platelet-aggregating effect of thromboxane A2 and the antiaggregating effect of prostacyclin, which causes clots to form at the site when a blood vessel is injured but keeps the vessel lumen free of clot Antithrombin III is a circulating protease inhibitor that binds to the serine proteases in the coagulation system, blocking their activity as clotting factors. This binding is facilitated by heparin, a naturally occurring anticoagulant that is a mixture of sulfated polysaccharides with molecular weights averaging 15,000–18,000. The clotting factors that are inhibited are the active forms of factors IX, X, XI, and XII.
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Handout 18.6: Structural of the Heart
Source Grays Anatomy, 2005
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Handout 18.7: Systole and Diastole
Source Gray’s Anatomy 2005
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Handout 18.8: Phases of Cardiac Cycle
Source Gray’s Anatomy, 2005
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Session 19: Structure and Functions of a Myelinated Neuron Total Session Time: 120 Minutes Prerequisites None Learning Tasks By the end of this session, students are expected to be able to: Describe the structure and functions of myelinated neuron Explain the functions of sensory and motor nerves Resources Needed Flipcharts, Marker pens and Masking tape Black/white board and chalk/whiteboard markers Anatomical charts Anatomical models and atlas LCD and Computer Handout 19.1: Structural of a Neuron SESSION OVERVIEW Step
Time
Activity/Method
Content
1
05 Minutes
Presentation
Presentation of the Session and Learning Tasks
2
55 Minutes
Structure and Functions of Myelinated Neuron
3
50 Minutes
Presentation, Buzz Presentation, Group Discussion
4
05 Minutes
Presentation
Key Points
5
05 Minutes
Presentation
Evaluation
Functions of Sensory and Motor Nerves
SESSION CONTENT Step 1: Presentation of Session Title and Learning Tasks (5 minutes) READ or ASK students to read the learning tasks and clarify ASK students if they have any questions before proceeding
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Step 2: Structure and Function of a Myelinated Neurone (55 minutes) Activity: Buzzing (5 minutes) ASK the students to pair up and explain how do they receive massage that they are holding a cold or hot object for 2 minutes ALLOW few pairs to responses and let other pairs to provide unmentioned responses CLARIFY and summaries by using the information below Nervous System The nervous system consists of a vast number of cell called neuron, supported by a special type of connective tissue, called neuroglia cells The nervous system detects and responds to changes inside and outside the body. Together with the endocrine system it controls important aspects of body function and maintains homeostasis. The physiological units of the nervous system are nerve impulses or action potentials which are like tiny electrical charges The nervous system consists of 3 main parts. o Central nervous system – CNS consists of the brain and the spinal cord. o The peripheral nervous system- PNS consists of nerves between the central nervous system and muscles and various organs. o Autonomic Nervous system consists of the two parts. Sympathetic Parasympathetic Neurone Neurones are commonly referred to as nerve cells Each neuron consists of a cell body and its processes, one axon and many dendrites Bundles of axons bound together are called nerves Neurone cannot divide, and for survival they need a continuous supply of oxygen and glucose Properties of Neurones Irritability – ability to initiate nerve impulses in response to stimuli from outside the body, e.g. touch; inside the body e.g. change in carbon dioxide in blood altering respiration Conductivity – ability to transmit an impulse Cell Bodies Forms the grey matter of the nervous system Found at peripheral of the brain and in center of the spinal cord. In groups are called nuclei in the central nervous system and ganglia in peripheral nervous system Axons and Dendrites Are extension of the cell bodies Form the white matter the nervous system NMT 04102 Anatomy and Physiology NTA Level 4, Semester 1
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Found deep in the brain and in groups, called tracts, at the peripheral of the spinal cord They are referred to as nerve fibers outside the brain and spinal cord. They carry impulses away from the cells (efferent nerve fibers) it can be up to one meter long. Each nerve cell has only one axon, carrying nerve impulses away from the body cell. Axons are usually longer than dendrites, sometimes long as 100 cm. Dendrites are the many short processes that receive and carry incoming impulses towards cell bodies In motor neurones dendrites form part of the synapses and in sensory neurone form the sensory receptor Refer Students to Handout 19.2: Lymph Node
The Functions of Myelin To protect the cylinder of axon. To stimulate a rapid transmission of impulses through the fiber. To act as an insulator for protection of an injury. o The Schwan cells produce the myelin sheet. o These are gaps between without myelin called the nodes of ranvier. o There are also non- myelinated fibers e.g. small fibers in CNS and post ganglion fibers. Nerve Impulse (Action Potential) Initiated by stimulation of sensory nerve endings or by passage of an impulse from another nerve Transmission of impulses is due to movement of ions across the nerve cell membrane The principal ions involved are sodium (Na+) the main extracellular cation and potassium (K+), the main intracellular cation
Step 3: Functions of the Sensory and Motor Nerves (50 minutes) Activity: Small Group Discussion ( 30 minutes) DIVIDE students into small manageable groups ASK students to discussion in groups on functions of sensory and motor nerves for 10 minutes ALLOW groups ask students to provide their response for 2 minutes each CLARIFY and summaries by using the contents below
There are two types of nerves. o Sensory nerves o Motor nerves
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Sensory or Afferent Nerves One that sending impulses to the spinal cord and the brain Sensory receptors are specialized endings of sensory nerves, responds to different stimuli (changes) inside and outside the body. They includes: o Somatic, cutaneous or common senses. These originate in the skin; they are pain, touch, heat and cold When stimulated, an impulse is generated and transmitted by the sensory nerves to the brain where the sensation is perceived. o Proprioceptor senses These originate in muscles and joints and contribute to the maintenance of balance and posture. o Special senses. These are sight; hearing, smell, touch and taste. o Autonomic afferent nerves. These originate in internal organs, glands and tissues e.g. baroreceptors; chemoreceptor’s and is associated with reflex regulations of involuntary activity and visceral pain. Motor or Efferent Nerves Motor nerves originate in the brain, spinal cord and autonomic ganglia controls, they transmit impulses to the efferent organs, muscles and glands, and there are two types. o Somatic nerves involved in voluntary and reflex skeletal muscles contraction. o Autonomic nerves (sympathetic and parasympathetic) involved in cardiac and smooth muscles contraction and glandular secretion.
Step 4: Key Points (5minutes)
The nervous system is the system that respond to changes inside and outside the body The parts of the nervous system are the central nervous system and peripheral nervous system The nervous system consist a vast number of nerve cells called neurones. The physiological unit of the nervous system are nerve impulses or action potentials Impulses are initiated by stimulating sensory nerve endings Sensory receptors respond to different stimuli while motor nerves transmit impulses
Step 5: Evaluation (5 minutes)
What are the physiological unit of the nervous system Mention the two main type of senses Explain the structure of a neurone
ASK students if they have any comments or need clarification on any points
References
Seeley, R. R., Stephens, T. D., & Tate, P. (2003) Anatomy and Physiology. New York: McGraw-Hill
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Shier, A., Butler, J. & Lewis, R. (2004). Hole’s Human Anatomy & Physiology. New York: McGraw-Hill Standring, S. (2008). Grays’s Anatomy The anatomical basis of clinical practice. United Kingdom: Churchill Livingstone Elservier. Thibodeau, G. A. & Patton, K. T. (1999). Anatomy & Physiology. Saint Louis: Mosby, Von Hoffman Press, Inc Waugh, A. & Grant, A. (2006). Ross and Willson Anatomy and physiology in Health and illness. United Kingdom: Churchill Livingstone Elservier
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Handout 19.1: Structural of a Neuron
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Session 20: Structure and Functions of the Central Nervous System Total Session Time: 120 Minutes Prerequisites Learning Tasks By the end of this session, students are expected to be able to: Identify the parts of the central nervous system Describe the structure and functions of the central nervous system Resources Needed Flipcharts, Marker pens and Masking tape Black/white board and chalk/whiteboard markers Anatomical charts Anatomical models and atlas LCD and Computer Handout 20.1: Structure of the Meninges Handout 20.2: The Cerebral Hemisphere Handout 20.3: Structure of the Brain Handout 20.4: Cerebrospinal Fluid Flow SESSION OVERVIEW Step
Time
Activity/Method Presentation
Content
1
05 Minutes
Presentation of the Session and Learning Tasks
2
25 Minutes
3
80 Minutes
4
05 Minutes
Presentation
Key Points
5
05 Minutes
Presentation
Evaluation
Presentation, Brainstorm Presentation, Group Discussion
Parts of the Central Nervous System Structure and Functions of the Central Nervous System
SESSION CONTENT Step 1: Presentation of Session Title and Learning Tasks (5 minutes) READ or ASK students to read the learning tasks and clarify ASK students if they have any questions before proceeding
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Step 2: Parts of Central Nervous System (25 minutes) Activity: Brainstorming (5 minutes) ASK the students to brainstorm parts of the central nervous system for 2 minutes ALLOW few students to responses and let other pairs to provide unmentioned responses WRITE their response on the flip chart/board CLARIFY and summaries by using the information below Central Nervous System The central nervous system consists of the brain and spinal cord.
Step 3: Structure and Funactions of the Central Nervous System (80 minutes) Activity: Small Group Discussion ( 30 minutes) DIVIDE students into small manageable groups ASK students to discussion in groups on the functions of the Central Nervous System for 10 minutes ALLOW groups ask students to provide their response for 2 minutes each CLARIFY and summaries by using the contents below Neurogria The neuron in the brain is supported by 4 different types of non- excitable glial cells that make up a quarter to a half of the volume of brain tissue, unlike nerve cells these continue to replicate throughout life. These glial cells are astrocytes, oligodendrocytes, microglial and epidermal cells. o Astrocytes. Transport nutrients, making up the blood brain barrier protecting the brain from some toxic substances that may enter the brain o Oligodendrocytes More irregular in shape makes the myelin sheet in the brain o Microglial Protect the nerve cells from infections. o Ependymal cells Form the epithelial lining of the ventricles of the brain and the central canal of the spinal cord. Membrane Covering the Brain and Spinal Cord (the Meninges) The brain and spinal cord are completely surrounded by three membranes, the meninges, lying between the skull and the brain and between the vertebrae and the spinal cord. Named from outside inwards they are:NMT 04102 Anatomy and Physiology NTA Level 4, Semester 1
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o Duramater The cerebral duramater consists of two layers of dense fibrous tissue. The outer layer takes the place of the periosteum on the inner surface of the skull bones and the inner layer provides a protective covering for the brain. There is only a potential space between the two layers called subdural space o Arachnoid mater. A delicate serous membranes lies between the dura and pia maters. It is separated from the dura mater by the subdural space, and from the pia mater by the subarachnoid space containing cerebrospinal fluid Many blood vessels are situated here. o Pia mater. A fine connective tissue containing many minute blood vessels. It adheres to the brain, completely covering the convolutions and dipping into each fissure. It continues down wards surrounding the spinal cord. No space under this layer. Ventricles of the Brain and the Cerebrospinal Fluid Within the brain there are four irregular – shaped cavities or ventricles containing cerebrospinal fluid (CSF.), this are: o Right and left lateral ventricles o Third ventricle o Fourth ventricle The lateral ventricles. o Lie within the cerebral hemispheres, one on each side of the median plane just below the corpus callosum. o Separated from each other by a thin membrane, the septum lucidum and are lined with ciliated epithelium. o They communicate with the 3rd ventricle by inter ventricular foramina. The third ventricle. o This is a cavity situated below the lateral ventricles. o It communicates with the fourth Ventricle by a canal, the cerebral aqueduct or aqueduct of the midbrain. The fourth ventricle. o Is diamond – shaped cavity situated below and behind the 3rd ventricle, between the cerebellum and pons o It is a continuous with a central canal of the spinal cord. o In this ventricle there are openings in the roof which allow the CSF to pass to the subarachnoid space that surrounds the brain and spinal cord. o The roof of each ventricle contains a network of capillaries called choroids plexuses. This is a part of pia mater. o The CSF is produced through the following. Sodium ions are actively secreted into the ventricles. o These positive ions draw negative Ions chloride ions into the ventricles. o The presence of these ions increases the pressure and cause water to pass by osmosis from the blood into the ventricles. Cerebral Spinal Fluid The osmotic pressure in CSF is 5 times higher than in the blood. NMT 04102 Anatomy and Physiology NTA Level 4, Semester 1
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The CSF is also reabsorbed into the blood; through the holes in the fourth ventricle the CSF enter the subarachnoid space. Arachnoid villi extend to this place where the permeability is high and the CSF can pass through into the dural sinuses and the venous system. The CSF in the brain and the spinal cord is = 120 – 150 ml. The pressure remains constant but can be increased in case of e.g. tumors, meningitis or hemorrhage. The content in the CSF is the same as in plasma but less protein. Cerebral Spinal Fluid is a clear, slightly alkaline fluid with a specific gravity of 1.005 consisting of: o water o Mineral salts o Glucose o Plasma proteins: Small amounts of albumin and globulin. o Creatinine in small amount o Urea in small amount o A few leukocytes.
Functions of Cerebrospinal Fluid It supports and protects the brain and spinal cord. It maintains a uniform pressure around these delicate structures. It acts as a cushion and shock absorber between the brain and the cranial bones. It keeps the brain and spinal cord moist and there may be interchange of substances between CSF and nerve cells, such as nutrients and waste products. The Brain The brain consists about one- fifth of the body weight and lies within the cranial cavity. The parts are: o Cerebrum o Midbrain o Pons The brain stem. o Medulla Oblongata o Cerebellum Blood Supply to the Brain The circulars artriosus and its contributing arteries, play a vital role in maintaining a constant supply of oxygen and glucose to the brain even when a contributing artery is narrowed or the head is moved. The brain receives about 15% of the cardiac output, approximately 750 ml of blood per minute. Autoregulation keeps blood flow to the brain constant by adjusting the diameter of the arterioles across a wide range of arterial blood pressure (about 65- 140 ml Hg) with changes occurring only outside these limits. The Cerebrum This is the largest part and most complex, it occupies the anterior and middle cranial fossae. It is divided into night and left hemispheres divided by the longitudinal cerebral tissue.
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The separation is complete in the front and the back but in the center they are joined by a broad band of white matter called corpus callosus. The outer part – the cortex is composed of gray matter arranged in folds gyri. The fissures between are called sulci.
Functional Areas of the Cerebrum The main areas of the cerebrum associated with sensory perception and voluntary motor activity are known but it is unlikely that any area is associated exclusively with only one function. o Motor areas The motor area. Situated immediately anterior of the ventral sulcus. The impulses pass through medulla oblongata out to the motor end plates in the muscles. The pre motor area lies in front of the motor area. Here you can find control of fine movement e.g. tying a shoe coordinated with the motor area. The motor speech area or Brocs area just above the temporal lobe and the lateral sulcus. Responsible for the speech. o The front area This part is less developed in animal’s behavior, character and intellectual states come from this area. Sensory area of the cerebrum. o The post central area (sensory) Behind the central sulcus, receives impulses from the opposite part of the body. Receives impulses from e.g. skin (touch, pain) etc. o The parietal area Behind the post central area. The function is associated with knowledge from the past and knowledge of objects. o The sensory speech area Situated in the lower part of the parietal lobe. The spoken words are received here. o The auditory area- Hearing Below the lateral. Impulses transmitted from the inner ear by the Vestibulocochlear nerve. The 8th cranial nerve. o The taste area Impulses from the taste buds on the tongue are received hear The 7th cranial nerve (facial nerve) The 9th cranial nerve (Glossopharyngeal nerve) o The visual area Occupies great area behind the parietal occipital sulcus. Both a motor and a sensory area. The 2nd cranial nerve optic nerve The 3rd cranial nerve oclomotor nerve. o Other areas of the cerebrum Areas deep in the brain that function as relay – stations. Transfer impulses from one neuron to another within the brain. Important masses of grey matter include Basal nuclei Thalamus NMT 04102 Anatomy and Physiology NTA Level 4, Semester 1
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Hypothalamus. The Basal Ganglia. Specialized on the planning and programming of movements. Disturbances in these will give difficulties with the posture and balance e.g. Parkinson’s disease o The thalamus Situated above hypothalamus and functions sensory relay station Diseases in this can give the patient a sensation of pain that will not be helped by analgesics. o The hypothalamus Provide connection between the endocrine system and the nervous system through the pituitary gland. Receives impulses from the internal organs system. Controls thirst, body temperature, appetite and blood pressure. Takes part in the limbic system where the subjective feelings of e.g. fear, anger and satisfactory are perceived. Also our sexual behavior is influenced by hypothalamus. Brain Stem The Midbrain This is the area of the brain situated around the cerebral aqueduct between the cerebrum above and the pons below. Is a relay station for ascending and descending impulses About 2 cm in length and the pineal body is situated here. The Pons Varolii Here we have the pnemotoxic center. It is situated in front of the cerebellum below the midbrain and above the medulla oblongata. It forms a bridge between the two hemisphere and medullas oblongata. Some of the cranial nerve has their relay station here e.g. 7th cranial nerve. The Medulla Oblongata It extends from the pons above and is continuous with the spinal cord below. It is about 2.5 cm long and it lies just within the cranium above the foramen magnum. There are two swelling one on each side called pyramids. The corticospinal fibers cross over to the other side of medulla in the lower part of some of the sensory fibers crossing over the spinal cord. The Vital Centers It consists of groups of cells associated with autonomic reflex activity, lie in its deep structure, these are. o The cardiac centre I t sends signals that regulate the heart. Sympathetic nerve- the force and rate increases. Parasympathetic – decreases the activity of the heart o Respiratory centre
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Works together with the pneumotoxic center in pons and regulate the rate and depth of breathing. Stimulated by the increased C02 in the blood and by impulses from the corotid bodies situated in the common corotid artery. o Vasomotor centre Signals sent to the muscles to contract and the vessels to constrict or dilate. o Reflex centre Vomiting, coughing, sneezing and swallowing. When irritating substances enter the body this center gives impulses to the body reflexes. Cerebellum It is situated under the occipital bone, divided into two hemispheres separated by a Worm shaped part the vermis. All actions from cerebellum take place unconsciously. The functions are concerned with posture and movement. Functions Maintain the muscle tone. coordinate muscular movement Maintain the balance. Receives sensory impulse from eyes and ears. The Spinal Cord This continue from the medulla oblongata = 45 cm and lies in the vertebrae column. The spinal cord ends at the level of the 1st lumbar vertebrae The meninges cerebral spinal fluid surround the spinal cord and in the same way but there is only one layer of dura matter. A prolongation of the spinal cord is called filum terminale Is the link between the brain and the rest of the body Nerves conveying impulses from the brain to various parts of the body descend through the spinal cord Functions of the Spinal Cord Provides conduction route to and from the brain Serves as the integrator, or reflex center, for all spinal reflexes
Step 4: Key Points (5 minutes)
Central nervous system consists of the brain and the spinal cord Is the ultimate regulator of the body, essential to survival Able to integrate bits of information from all over the body
Step 5: Evaluation (5 minutes)
What is the term used to describe the membrane covering the brain and the spinal cord? Mention the functions of the hypothalamus What are the large fluids –filled spaces within the brain called? How many are they? What do they contain
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ASK students if they have any comments or need clarification on any points
References
Seeley, R. R., Stephens, T. D., & Tate, P. (2003) Anatomy and Physiology. New York: McGraw-Hill Shier, A., Butler, J. & Lewis, R. (2004). Hole’s Human Anatomy & Physiology. New York: McGraw-Hill Standring, S. (2008). Grays’s Anatomy The anatomical basis of clinical practice. United Kingdom: Churchill Livingstone Elservier. Thibodeau, G. A. & Patton, K. T. (1999). Anatomy & Physiology. Saint Louis: Mosby, Von Hoffman Press, Inc Waugh, A. & Grant, A. (2006). Ross and Willson Anatomy and physiology in Health and illness. United Kingdom: Churchill Livingstone Elservier.
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Handout 20.1: Structure of the Meninges
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Handout 20.2: The Cerebral Hemisphere
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Handout 20.3: Structure of the Brain
Source: Moore, Keith L.; Agur, Anne M. R 2007
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Handout 20.4: Cerebrospinal Fluid Flow
Source: Lippincott Williams & Wilkins Moore, Keith L.; Agur, Anne M. R.2007
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Session 21: Structure and Functions of the Peripheral and Autonomic Nervous System Total Session Time: 120 Minutes Prerequisites None Learning Tasks By the end of this session, students are expected to be able to: Describe the structure and functions of the peripheral nervous system Describe the structure and functions of the autonomic nervous system Resources Needed Flipcharts, Marker pens and Masking tape Black/white board and chalk/whiteboard markers Anatomical charts Anatomical models and atlas LCD and Computer Handout 21.1: The Structure of the Cranial Nerve Handout 21.2: Cranial Nerve Handout 21.3: Cross Section of the Spinal Cord Hand out 21.4:Brachial Plexus Handout 21. 5: The Organization of the Autonomic Nervous System Handout 21.6: The Organization of the Peripheral Nervous System Handout 21.7: Dermatomes (Cervical, Brachial and Lumbar plexus) Handout 21.8: Dermatomes (Lumbar, Sacral and Coccygeal plexus) SESSION OVERVIEW Step
Time
Activity/Method
Content
1
05 Minutes
Presentation
Presentation of the Session and Learning Tasks
2
55 Minutes
3
50 Minutes
4
05 Minutes
Presentation
Key Points
5
05 Minutes
Presentation
Evaluation
Presentation, Group Discussion Presentation, Group Discussion
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Structure and Functions of the Peripheral Nervous System Structure and Functions of the Autonomic Nervous System
Session 21: Structure and Functions of the Peripheral and Autonomic Nervous System
SESSION CONTENT Step 1: Presentation of Session Title and Learning Tasks (5 minutes) READ or ASK students to read the learning tasks and clarify ASK students if they have any questions before proceeding
Step 2: Structure and Functions of the Peripheral Nerves (55 minutes) Activity: Small Group Discussion ( 30 minutes) DIVIDE students into small manageable groups ASK students to discussion in groups on the functions of the Peripheral Nerves for10 minutes ALLOW groups ask students to provide their response for 2 minutes each CLARIFY and summaries by using the contents below
The peripheral nervous system consists of the cranial nerves and spinal nerves There are 12 pairs of cranial nerves originating from medulla into the inferior surface of the blain, some are sensory, some motor and some mixed. They are named according to their attachment in the brain from the front to the back; they also have names according to the functions.
The Cranial Nerves NAME
NUMBER
FUNCTIONAL CLASSIFICATION
Olfactory
I
Sensory
Optic
II
sensory
Oculomotor
III
Motor
Trochlear
IV
Motor
Trigeminal
V
mixed
Abducens
VI
motor
Facial
VII
mixed
Vestibulocochlear (auditory)
VIII
sensory
Glossopharyngeal
IX
mixed
Vagus
X
mixed
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Accessory
XI
motor
Hypoglossal
XII
motor
Refer Students to Handout 21.1: Structure of the Cranial Nerve Function Olfactory Nerves (Sensory) Nerves of the sense of smell. Their nerve endings and fibers originate in the upper part of the mucous membrane of the nasal cavity, pass upwards through the cribriform plate of the ethnoid bone and then go to the olfactory bulb. The nerves then proceed backwards as the olfactory track, to the area for the perception of small in the temporal lobe of the cerebellum. Optic Nerves (Sensory) Nerves of the sense of sight. The fibers start in the retina of the eyes and they combine to form the optic nerves. The impulses from the sight are also important to the maintenance of posture and balance Oculomotor Nerves (motor) Starts in the midbrain and ends in the b muscles which move the eyes. Also control the size of the pupil. Trochlear Nerves (motor) Arise from the nerve cells near the cerebral in aqueduct. Supply the superior oblique muscles of the eyes and also the lateral lactus Trigeminal Nerves (mixed) The largest cranial nerve most sensory but one part motor which supply the muscle of mastication o Ophthalmic branch. o Maxillary branch. o Mandibular branch. Abducens Nerves (Motor) These nerves arise from a group of nerve cells lying under the floor of the fourth ventricle. They supply the lateral rectus muscles of the eyeballs. Paralysis of this nerves results into squint Facial (Mixed) These nerves are composed of both motor and sensory nerve fibres, arising from nuclei in the lower part of the pons. Vestibulocochlear Nerves (Auditory Nerves) (Sensory) One set of fibers transports the impulses of hearing; the other set transports the Impulses of balance. NMT 04102 Anatomy and Physiology NTA Level 4, Semester 1
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They start in cochlear and end up in medulla.
Glossopharyngeal Nerve (Mixed) Sensory fibers supply pharynx< including the taste buds, Motor fibers helps in swallowing and speaking lifting up the pharynx Vagus Nerves (Mixed) The nerve is distributed to pharynx, larynx, trachea, bronchi, lungs, heart, oesophagus, stomach, upper intestine and kidney. The function of this nerve is secretion and movement The Accessory Nerve – (Motor) Originate partly in medulla and partly in the cervical part of the spinal cords the function is movement of the head, shoulders, ribs, larynx and pharynx The Hypoglossal Nerve (Motor) These nerves control the movement of the tongue in speech and swallowing. Spinal Nerves Each spinal nerve attaches to the spinal cord by means of two short roots, a ventral (anterior) root, and a dorsal (posterior) root Short distance from the spinal cord the roots unite to form a spinal nerve There are 31 pairs of spinal nerves that leave the vertebral canal by passing through the intervertebral foramina formed by adjacent vertebrae. They are named and grouped according to the vertebrae with which they are associated or according to the vertebrae they leave. o 8 cervical nerves o 12 thoracic nerves o 5 Lumbar nerves o 5 Sacral nerves o 1 Coccygeal nerves
Refer Students to: Handout 21.3 : Cross Section of the Spinal Cord Handout 21.4: Brachial Plexus All the spinal nerves are mixed nerves; They have impulses from the anterior branch which takes impulses from the anterior part of the body and the limbs. The posterior branch takes impulses from the muscles and skin of the posterior part of the body. The spinal nerves in the thoracic and lumbar area also have a visceral branch which transmits impulses to the internal organs. Each spinal nerve has a sympathetic part that forms ganglion.
Plexuses The ventral rami of the spinal nerves, except for T2 to T12, do not go direct to the structures of the body they supply. Instead, they form networks with the adjacent nerves on either side of the body NMT 04102 Anatomy and Physiology NTA Level 4, Semester 1
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Such a network is known as a Plexus There are 5 large plexuses of mixed nerves formed on each side of the vertebral column, this are: o Cervical plexus Formed by C1 to C4 Supplies the skin and muscles of the head, neck, and upper limbs o Brachial plexus Formed by C5 to C8 and T1 Supplies the upper limbs, and the axilla o Lumbar plexus Formed by L1 to L4 Supplies the anterolateral abdominal wall, external genetelia, and part of the lower extremities o Sacral plexus Formed byL4 to L5 and S1 to S4 The largest nerve in the body - sciatic nerve arise here Damage to sciatic nerve may lead to foot drop, inability to dorsiflex the limb Refer Students to Handout 21.2: The Cranial Nerve
Step 3: Structure and Functions of The Autonomic Nervous System(50 minutes) Activity: Small Group Discussion ( 30 minutes) DIVIDE students into small manageable groups ASK students to discussion in groups on structure the functions of the Integumentary System 10 minutes ALLOW groups ask students to provide their response for 2 minutes each CLARIFY and summaries by using the contents below
In association with the endocrine system, the autonomic nervous system is `responsible to maintain internal environment. In body even if changes takes place outside we call this system self-contracting. The autonomic system consists of efferent motor nerve but sensory fibers from different sources stimulate the system. All autonomic pathways composed of two neurons.
Refer Students to: Handout 21.5: The Organization of Autonomic System Handout 21.6: The Organization of the Peripheral Nervous System
Preganglionic Neuron Transmits the impulses to the next ganglion with the transmitter substances Acetylcholine. NMT 04102 Anatomy and Physiology NTA Level 4, Semester 1
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This ganglion is myelinated we call this ganglion cholinergic. The impulses to the next ganglion are depending on which type of receptors that are present.
Post Ganglionic Neuron Transmit the impulses to smooth muscles or glands by the help of adrenaline or noradrenalin. They are called adrenergic neuron. The adrenal medulla secretes the same hormones into the blood stream but is not a part in the autonomic neuron system. Organs that respond to the release of adrenaline or noradrenalin have one or two different receptors these are:X-receptors (Alfa Receptors) When stimulated they cause vasoconstriction relaxation of intestinal smooth muscles and dilatation of iris of the eyes. B- receptors (beta receptors) When stimulated they cause vasodilatation acceleration of rate and force of the heart, bronchodilator, relaxation of intestine smooth muscles and release of fatty acids and glucose into the blood. The Autonomic Neuron System Sympathetic system Parasympathetic system. The Sympathetic Neuron System This originates in the thoracolumbar part of the spinal cord. The general functions are to increase the heart rate bronchioles, stimulate sweating etc. The chain of ganglia pass through the anterior not and are corrected in special groups of plexuses, Two most important plexuses are:o The cardiac plexuses. o The cardiac plexuses –solar plexuses situated behind the diaphragm. The Parasympathetic Neuron System Consists of ganglia which are associated with cranial nerves, the impulses are opposite with cranial nerves III, VII, IX, and X e.g. after stimulation, pupil will be constricted, rate and force of the heart rate will be decreased and secretion decreased. Refer Students to: Handout 21.7: Dermatomes (Cervical, Brachial and Thoracic Plexus) Handout 21.8: Dermatomes (Lumbar, Sacral and Coccygeal Plexus) The Sacral System This system supplies structures in pelvis including rectum , urinary bladder , uterus and other reproductive organs e.g. after stimulation the motility in the large intestines
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will be increased and the muscles in the bladder will be constricted while the sphincters will relax.
Step 4: Key Points (5 minutes)
The peripheral nervous system is made up of all the afferent nervous pathways coming out into the CNS and all the efferent pathways going out of the CNS There are twelve cranial nerves named with numbers from 1 to 12 All spinal nerves are mixed nerves 31 pairs of spinal nerves are connected to the spinal cord The autonomic neuron system consists of the Sympathetic system and Parasympathetic system
Step 5: Evaluation (5 minutes)
Explain the twelve cranial nerve What is the largest nerve in the body and what happens when it is damaged How do sympathetic and parasympathetic systems work?
ASK students if they have any comments or need clarification on any points
References
Seeley R. R, Stephens T. D, Tate P. (2003) Anatomy and Physiology. New York: McGraw-Hill Shier A, Butler J & Lewis R (2004). Hole’s Human Anatomy & Physiology. New York: McGraw-Hill Standring S. (2008). Grays’s Anatomy The anatomical basis of clinical practice. United Kingdom: Churchill Livingstone Elservier. Thibodeau G. A. Patton K. T. (1999). Anatomy & Physiology. Saint Louis: Mosby, Von Hoffman Press, Inc Waugh A & Grant A (2006). Ross and Willson Anatomy and physiology in Health and illness. United Kingdom: Churchill Livingstone Elservier. Tortora G. J. & Anagnostakos N. P. Prnciples of Anatomy and Physiology, 3rd edition, Happer & Row Publishers, New York
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Handout 21.1: Summary of the Cranial nerve Functions Cranial Nerve No I II III IV V VI VII
VIII IX
X
XI XII
Name
Function
Olfactory Optic Oculomotor
Olfaction Vision Eye movement Parasympathetic innervations of eye Trochlear Eye movements Trigeminal General sensation from head, Motor to muscles of mastication Abducens Eye movements Facial Taste Hearing Parasympathetic innervations of salivary and lacrimal glanda Vestibulocochl Vestibular sense ear Hearing Glossopharyn Taste geal General sensory and motor innervations of pharynx Visceral innervations from carotid body and sinus Parasympathetic innervations of salivary gland Vagus General sensory and motor innervations of pharynx, larynx and oesophagus Visceral innervations from thorax and abdomen, including aortic body and arc Parasympathetic innervations of thoracic and abdominal viscera Accessory Movement of head and shoulders Hypoglossal Movements of tongue
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Handout 21.2: Cranial Nerve
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Handout 21.3: Cross section of the Spinal Cord
.
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Handout 21.4: Brachial Plexus
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Handout 21. 5: Organization of Autonomic Nervous System
Source: Www. Peripheral Nervous System/Autonomic Nervous System
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Handout 21. 6: Organization of Peripheral Nervous System
Source: Keith, Agur, Anne (2007).
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Handout 21.7: Dermatomes (Cervical Plexus, Brachial Plexus, Thoracic Nerves)
Anterior
Posterior
Source: Keith, Agur, Anne (2007). L\
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Handout 2 1. 8: Dermatomes (Lumbar Plexus, Sacral Plexus, and Coccygeal Plexus)
Anterior
Posterior
Source: Moore, Keith, Agur, Anne (2007).
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Session 22: Structure and Functions of the Endocrine System Total Session Time: 120 Minutes Prerequisite None Learning Tasks At the end of this session the students are expected to be able to: Identify the organs of the endocrine systems system Describe the structure and functions of the endocrine system Resources Needed Flipcharts, Marker pens and Masking tape Black/white board and chalk/whiteboard markers Anatomical charts Anatomical models and atlas LCD and Computer Handout 22.1:Endocrine Gland and its Hormones Handout 22.2; Pituitary and its Pineal Gland Handout 22.3: Hormone Produced by Anterior and Posterior Lobes of the Pituitary Handouts 22.4: Location of Human Hypothalamus Handout 22.5 :Position of the Thyroid Gland Handout 22.6: Pituitary Master Gland Handout 22. 7 The Brain Showing the Position of the Hypothalamus SESSION OVERVIEW Step
Time
Activity/Method
Content
1
05 Minutes
Presentation
Presentation of Session Title and Learning Tasks
2
25 Minutes
3
80 Minutes
4
05 Minutes
Presentation
Key Points
5
05 Minutes
Presentation
Evaluation
Presentation, Organs of the Endocrine System Brainstorm Presentation, Structure and Functions of the Endocrine System Group Discussion
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Step 2: Organs of the Endocrine System (25minutes) Activity: Buzzing (5 minutes) ASK the students to pair up and list the organs of the endocrine system for 2 minutes ALLOW few students to respond and let other pairs to provide unmentioned responses CALRIFY and summarize by using the information below
The glands of the body may be divided into those with external secretion (exocrine glands) and those with internal secretion (endocrine glands) Examples of exocrine glands are the sweat, lachrymal and mammary glands which pass their secretion along the ducts to the external surface of the body and the glands of the mouth, stomach, and intestine which pass their secretions along ducts into the alimentary tract. The endocrine or ductless gland on the other hand has no ducts or openings to the exterior; their secretions are passed directly into the blood stream and transmitted to the tissues. A hormone is a chemical substance produced by the endocrine glands and their overall function is to regulate the activities of various body organs and their functions. The first hormone was discovered by Bayliss in 1903.
The Main Endocrine Glands in the Body Thyroid Parathyroid Islets of Langerhans Adrenal gland Pituitary and Sex glands. Refer Students to Handout 22.7: Endocrine Gland and its Hormones
Step 3: Structure and Functions of the Endocrine System (80 minutes) Activity: Small Group Discussion ( 30 minutes) DIVIDE students into small manageable groups ASK students to discussion in groups on the functions of the endocrine System for 10 minutes ALLOW groups ask students to provide their response for 2 minutes each CLARIFY and summaries by using the contents below Thyroid Gland The largest of the endocrine glands is the thyroid which is located in the neck region. NMT 04102 Anatomy and Physiology NTA Level 4, Semester 1
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The thyroid gland weighs 25gms in a healthy adult. It has two oval parts called the lateral lobes on either side of the trachea. These two lobes are connected by a narrow band called isthmus. The entire gland is enclosed by a connective tissue capsule. This gland produces hormone, thyroxin rich in iodine. Thyroid gets iodine from the blood stream. It is then fixed with the amino acids thyroxin compounds. By eating vegetables grown in iodine –containing soils or by eating sea – foods and iodized salt the body gets sufficient amount of iodine for the production of thyroxin. Thyroid stimulating hormone (TSH) produced by the anterior pituitary lobe increases the activity of thyroid gland. Whenever, the thyroxin level falls below a particular level TSH is stimulated.
Functions of Thyroxin Helps to regulate tissue growth and development Increases the BMR and thus raises the body It controls the metabolism by regulating the anabolic and catabolic process. Stimulates the cells to break down the proteins for energy. Decreases the breakdown of fats Increases the breakdown of body glucose and enhances the glucose absorption. Calcium and phosphorus are removed from the bones and excreted in increased amounts. Helps in the conversion of beta – carotene into vitamin A. Refer Students to Handout 22.5: Position of the Thyroid Gland Parathyroid Gland These are two tiny oval pair (6mm x 2mm) of glands situated at upper and lower poles of lateral lobes of thyroid gland. It secretes the hormone parathyroxine. Functions of Parathyroxine Increases the concentration of organic acid in the bone. Increases the calcium and phosphorus solubility Increases the reabsorption of calcium from the bones resulting in increased serum calcium level. Increases phosphate excretion in the urine. Increases the reabsorption of calcium from the renal tubules. Promotes the absorption of calcium and phosphorus from the intestine. Stimulates the process of lactation in mammary gland. Islets of Langerhans in the Pancreas The pancreas is both an exocrine gland secreting digestive juice through a duct into the duodenum and an endocrine gland secreting hormone into the bloodstream. It consists of head, body and tail. The head fit into the curve of duodenum. Then body and tail are directed towards the left. The pancreatic islets represent the endocrine part of the pancreas. NMT 04102 Anatomy and Physiology NTA Level 4, Semester 1
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Most of the islets are located in the tail and only a small number in the head of the pancreas. There are two different types of cells in the islets of Langerhans. The alpha cells and beta cells are very important. The alpha cells secrete a hormone Glucagon The beta cells secrete insulin.
Functions of Glucagon Increases the blood glucose level Break down the liver glycogen into glucose. Stimulates the breakdown of lipid in adipose tissue. Functions of Insulin Converts glucose into glycogen and accelerates the transport of glucose from the blood into the cells. Decreases the blood sugar level Builds up the glycogen store in the liver. Adrenal Gland The adrenal or supra renal are two small glands each one situated above a kidney. Adrenal gland consists of two different parts each of which acts as a separate gland. The inner area is called medulla which is brown in colour while the outer area is called the cortex which is lighter in colour. Adrenal Cortex It is composed of three layers. Zona glomerulosa (outer layer) Zona Faciculate (middle layer) Zona reticularis (inner layer). The adrenal cortex secretes three hormones. Glucocorticoids Acts as antagonists to insulin and cause increase in blood sugar. Mineral corticoids: Acts on sodium and potassium and help in the conservation of sodium in the body. Sex steroids : Stimulates the development of there productive organs in child hood. It is responsible for development of secondary sex characteristics and reproductive function. Adrenal Medalla Adrenal Medalla secretes hormones. Adrenaline and nor – adrenaline. Functions of Medullary Hormones Dilation of the pupils and improves visual acuity. Increases both rate and amplitude of contraction of heart and raises the cardiac output. Increases both rate and amplitude of respiratory movements and causes dilation of the bronchioles. NMT 04102 Anatomy and Physiology NTA Level 4, Semester 1
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Raises the blood sugar level by means of glycogenolysis Increases the basal metabolic rate. Dilation of the walls of intestine and the urinary bladder. The functions of adrenaline are not similar to that of nor –adrenaline except in a few instances e.g. adrenalin increases the heart rate where as nor – adrenalin decreases heart rate.
Pituitary Gland The pituitary is a small gland about the size of a cherry. It is situated at the base of the brain. It plays a peculiar role in the system of endocrine glands. It is referred to as the master gland of internal secretion because it controls the activities of other endocrine glands. Two Main Parts of the Pituitary Gland Anterior pituitary and Posterior pituitary The Anterior Pituitary o This part secretes a large number of hormones. o Many of them stimulate other glands. o Its main hormones are: Growth Hormone: It facilitates the growth of the bone and cartilage tissue. Over activity of the anterior pituitary lobe in childhood results in excessive growth and height this condition is known as gigantism. A decreased activity of the anterior pituitary causes a severe growth retardation leading to dwarfism. Excessive production of growth hormone in an adult leads to excessive development of certain regions such as fingers and toes, feet, hands, nose, lower jaw, tongue, thoracic and abdominal organs this condition is known as acromegaly. o Thyrotrophic stimulating hormone (TSH): This hormone stimulates the activity of the thyroid gland. Administration of this hormone causes over growth of thyroid tissue. Adrenocorticotropic hormone: (ACTH): This hormone stimulates the cortex of the adrenal gland and increases the production of the hormones of adrenal cortex. Follicle stimulating hormone (FSH): This hormone influences the growth, development and maturation and of the ovarian follicles. In males, the hormone stimulates the formation of sperm in the testes. Prolactin hormone: It acts on the mammary gland and helps in the formation and flow of milk during lactation. Luteinizing hormone: It is required for the growth of follicle in the ovary and stimulates ovulation. In the absence of the hormone, no ovulation and production of the corpus luteum can occur. In males it stimulates the interstitial cells of testes to secrete testosterone.
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Refer Students to: Handout 22.2: Pituitary and Pineal Gland Handout 22.3: Hormone Produced by Anterior and Posterior Lobe of the Pituitary Gland Handout 22.4: Location of Human Hypothalamus Handout 22.6: Pituitary Master Gland Handout 22.7: The Brain Showing the Position of the Hypothalamus
Posterior Lobe of the Pituitary This lobe is just behind the anterior lobe. It produces two hormones oxytocin and vasopressin. o Oxytocin Acts on the smooth muscles especially that of the uterus and produces powerful contractions of the uterus and helps in parturition. o Vasopressin Acts on the smooth muscle of the arterial system and increases the blood pressure. Convoluted tubule. Vasopressin deficiency is the cause of diabetes insipidus in which water is not reabsorbed. So great amounts of urine are excreted with no sugar in it such patients feel constantly thirsty. The Sex Glands The sex glands including the ovaries of the female and the testis of the male are important endocrine structures. The secretions of this gland play an important part in the development of the sexual characteristics. The male sex gland secretes hormone called testosterone and is responsible for secondary sex characteristics. The female sex gland secretes a hormone called estrogen and it stimulates the development and functioning of the female reproductive organs. There is one other hormone produced by female sex gland and it is called progesterone. This hormone assists in the normal development of the pregnancy.
Step 4: Key Points (5 minutes)
The glands of the body may be divided into those with external secretion (exocrine glands) and those with internal secretion (endocrine glands) A hormone is a chemical substance produced by the endocrine glands and their overall
Step 5: Evaluation (5 minutes)
Mention the glands that make up the endocrine system What is the difference between exocrine and endocrine gland
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References
Seeley R. R, Stephens T. D, Tate P. (2003) Anatomy and Physiology. New York: McGraw-Hill Shier A, Butler J & Lewis R (2004). Hole’s Human Anatomy & Physiology. New York: McGraw-Hill Standring S. (2008). Grays’s Anatomy The anatomical basis of clinical practice. United Kingdom: Churchill Livingstone Elservier. Thibodeau G. A. Patton K. T. (1999). Anatomy & Physiology. Saint Louis: Mosby, Von Hoffman Press, Inc Waugh A & Grant A (2006). Ross and Willson Anatomy and physiology in Health and illness. United Kingdom: Churchill Livingstone Elservier. Tortora G. J. & Anagnostakos N. P. Prnciples of Anatomy and Physiology, (3rd ed), Happer & Row Publishers, New York
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Handout 22.1: Endocrine Glands and its Hormones
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Handout 22.2: Pituitary and Pineal Gland
Source: Strandring (2005)
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Handout 22.3: Hormones Produced by the Anterior and Posterior Lobes of the Pituitary
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Handout 22.4: Location of Human Hypothalamus
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Handout 22.5: Position of Thyroid Gland
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Handout 22.6: Pituitary Master Gland Hormone
Target Organ or Tissue
Adrenocorticotropic hormone (ACTH)
Adrenal glands
Antidiuretic hormone
Kidney
Beta-melanocyte–stimulating hormone
Skin
Endorphins
Brain and immune system
Enkephalins
Brain
Follicle-stimulating hormone
Ovaries or testes
Growth hormone
Muscles and bones
Luteinizing hormone
Ovaries or testes
Oxytocin
Uterus and mammary glands
Prolactin
Mammary glands
Thyroid-stimulating hormone
Thyroid gland
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Handout 22.7: The Brain Showing the Position of the Hypothalamus
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Session 23: Structure and Functions Musclar System Total Session Time: 120 Minutes Prerequisite None Learning Tasks By the end of this session, students are expected to be able to: Identify the types of muscle tissue Describe the structure of muscle Mention the general functions of muscles Explain the chief muscle of the body Resources Needed Flipcharts, Marker pens and Masking tape Black/white board and chalk/whiteboard markers LCD Computer/laptop Anatomical charts Handout 23.1: Muscles of the Body SESSION OVERVIEW Step
Time
Activity/Method
Content
1
05 Minutes
Presentation
2
30 Minutes
Presentation
3
15 Minutes
4
60 Minutes
5
05 Minutes
Presentation
Key Point
6
05 Minutes
Presentation
Evaluation
Presentation of the Session Learning Tasks Types of Muscle Tissue and Their Structure
Presentation, General Functions of Muscles Buzz Presentation, Chief Muscle of the Body Group Discussion
SESSION CONTENT Step 1: Presentation of Session Title and Learning Tasks (5 minutes) READ or ASK students to read the Learning tasks and clarify ASK students if they have any questions before proceeding
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Step 2: Types of Muscle Tissue and Structure (30 minutes)
The muscular system consists of a large number of muscles concerned with movements of the body. Voluntary muscles are attached to bone, cartilages, ligaments, skin or to other muscles in order to stimulate movements
Types of Muscle Tissue Skeletal muscle (also called striated muscle) Cardiac muscle (the muscle of the heart) Visceral muscle (also called smooth muscle) Skeletal Muscle Is the most abundant type of muscle t attaches to bone and so is important in producing movements in our joints and maintaining our posture. Under the microscope, skeletal muscle cells look like long fibres and have a striped (striated) appearance. We generally think of skeletal muscle as being under voluntary control. Cardiac Muscle Is the muscle of the heart Under the microscope, cardiac muscle cells also appear striated; however the striations are not as well organized as in skeletal muscle. The activity of cardiac muscle is controlled to a large degree by the autonomic nervous system. We generally think of cardiac muscle as being involuntary. Visceral Muscle Is the muscle which lines our blood vessels and internal organs Under the microscope, visceral muscle cells do not have the obvious striations of skeletal or cardiac muscle hence called smooth muscle. Visceral muscle cells are often relatively short, and usually they each have only one nucleus. We generally think of visceral muscle as being involuntary. The ability of muscle to contract depends on the presence of two protein molecules: actin and myosin. Bundles of actin and myosin molecules are arranged end to end in muscle cells. It is these bundles that give skeletal and cardiac muscle their striated appearance. When a muscle is properly stimulated, the actin and myosin bundles slide together and so the muscle cell gets shorter. This process requires calcium and ATP for energy. Muscles, especially skeletal muscle, may be stimulated to contract by motor nerves. Depolarization from a motor nerve causes calcium to move from the sarcoplasmic reticulum into the sarcoplasm. This release of calcium causes actin and myosin to slide together and shorten the muscle.
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Step 3: Functions of Muscle Tissue (15 minutes) Activity: Buzzing (5 minutes) ASK students to a pair up and discuss the function of muscles for 2 minutes ALLOW few student to respond, let other responses for unmentioned responses WRITTE the responses on the board/flip chart CLARIFY and summarizes by using information below
General Functions of Muscle Tissue Initiation of contraction being stimulated autonomic nerve impulses –smooth and cardiac muscle tissue Moving bones by skeletal muscle tissue Covering body cavities Protecting some body structures Shaping of body (morphology) Muscle Tone Muscle tone is a state of partial contraction of muscle Few muscle fibres contract at a time Skeletal muscle tone is essential for maintenance of posture in sitting and standing position Muscle Fatigue If a muscle is stimulated to contract at very frequent intervals, the responses gradually becomes depressed and ceases.
Step 4: The Chief Muscles of the Body(60minutes) Activity: Small Group Discussion ( 30 minutes) DIVIDE students into small manageable groups ASK students to work in groups and list the chief muscles of the body for 10 minutes ALLOW groups ask students to provide their response for 2 minutes each CLARIFY and summaries by using the contents below Muscle of the Head The muscle of the head are divided into two groups: Muscles of expression and muscles of mastication
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Refer Students to Handout 23.1: Diagram of Body Muscle Tissue Name Muscle of expression
Muscles of mastication
Name Orbiculis oculi (circular muscles)
Position
Origin Skin
Insertion Eye
Obicularis oris
Mouth
i) Masseter (broad muscles) ii) Temporalis muscle
- Zygomatic arch to the right angle of jaw Temporal bone
Action Closes eye Screws up the eye Closes lip Shapes mouth
- Draws mandible and maxilla - Closes jaw -Draws mandible
Muscle of the Neck Name
Position
Origin
Insertion
Sternocleidomastoid
Side of the neck
Sternum and clavicle
Mastoid process Turns head to the side Tilts to same shoulder Flex of the neck
Trapezius
Back of the neck and shoulder
Occiput Spines of thoracic vertebra
Zygomatic arch to the right angle of jaw
Muscles of mastication i) Masseter (broad muscles)
Temporal bone
Draws scapula back Raises and lowering of shoulder Extending neck - Draws mandible and maxilla - Closes jaw
- Draws mandible
ii) Temporalis muscle
Clavicle Spine of scapula
Action
Muscles of the Trunk o Muscle moving shoulder o They are powerful muscles o They also connect the upper limb and the trunk
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Name
Position
Origin
Insertion
Action
i) Pectoralis major
Front of chest
- Sternum Humerus and clavicle (bicipital - Cartilages of groove) true ribs
Adducts shoulder Draws the arm across front chest Rotates shoulder internallis
ii) Lattissimus dorsi
Crosses the back from lumbar region to shoulder
Lower thoracic lumbar and sacral vertebrae Iliac crest
Humerus (bicipital groove)
Adducts the shoulder Draws arm back wards and downs in bell pulling Internal rotation of shoulder
iii) Serratus anterior
- Over the side of the thorax - Under scapula
Front of the eight upper ribs
Medial border of scapula
Draws scapula forwards; antagonistic to the trapezius
Muscle of Respiration Name
Position
Origin
Insertion
Action
i) Diaphragm (dome shaped sheet)
Between thoracic and abdominal cavity
- Tip of sternum, lower ribs - Thee lumber vertebrae
Central aponeurosis
- Involved in the mechanism of respiration
ii) External intercostals muscle
Between the ribs
- Lower border of rib above
Upper - Draw ribs upwards border of the and downwards rib below
iii) Internal intercostals muscle
Between the ribs
- Lower border of the rib above
Upper - Draw ribs downwards border of the and inwards to rib below decrease the size of the thorax in force expiration - Antagonistic external intercostals muscle
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Muscle of the Abdominal Wall Name
Position
Origin
Insertion
Action
i) Rectus abdominis (Resctus = straight)
Anterior abdominal wall
- Pubis, sternum and costal cartilage
Abdominal wall
- Forms the anterior wall of abdominal wall
ii) External oblique
Lateral abdominal wall
- Lower ribs
Iliac crest and inguinal ligament
- Attaches muscle - Forms lateral wall of the abdominal wall
iii) Internal oblique
Lateral abdominal wall
- Lower ribs
Iliac crest and inguinal ligament
- Form firm wall of abdomen - Give attachment to muscle
iv) Transversus abdominis
Under the internal oblique
- Illiac crest and lumber fascia
Aponeurosis across the front wall of abdomen
- Forms the lateral wall of the abdominal wall
v) Quadratus lumborum
Lateral and posterior wall
- Iliac crest to 12th rib - Upper lumbar vertebrae
Iliac crest and inguinal canal
Muscle of the Hip These are muscles of the trunk moving the hip Name Position Origin
- Forms the posterior wall of the abdominal wall - Holds the 12th rib during breathing
Insertion
Action
i) Psoas major
Crosses the region behind inguinal ligament
Transverse processes of lumber vertebrae
Lesser o femur
Flexes the hip
ii) Iliucus
Crosses the groin behind the inguinal ligament with psoa
Front surface of the iliac bone
Lesser trochanter of femur
Flexes the hip
iii) Gluteal muscles
Cross the back of the hip
Posterior surface of ilium and sacrum
Greater trochanter and gluteal line of femus
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- Extends, abducts hip laterally - Rotates hip
Session 23: Structure and Functions Muscular System
Muscle of the Pelvic Diaphragm The pelvic diaphragm consists of muscles forming the support of the pelvic organs Runs from the pubis in front back to sacrum and coccyx The pelvic diaphragm is composed of the levator ani and coccygeus muscles In the female it is pierced in the middle by three openings for the urethra, vagina and rectum. In the male there are two openings, for the urethra and the recturm respectively. Muscle of the Arm Name
Position
Origin
Insertion
Action
i) Biceps
Front of the arm
- Coracoid Radial process tuberosity - Above glenoid cavity of scapula
- Flexes elbow, shoulder - Supinates the hand
ii) Triceps (three heads)
Back of the arm
- One head the axillary border of scapula
Olecramon of ulna
- Extends elbow and shoulder
iii) Deltoid
Over the shoulder
- Acromion and spine of scapula, the clavicle
Detoid tuberosity of humerus
- Abducts the shoulder to a right angle
iv) Brachialis
Crosses the front elbow
- Humerus
- Anterior surface of coronoid process of ulna
- Flexes the elbow
Muscle of the Forearm and Hand The muscles for the forearm are numerous powerful muscles for movement of the wrist and digits The muscle are: o Pronator teres o Flexor carpiulnalis o Flexar carpi radialis o Pronator quadratus o Flexor renaculum o Thenar eminence o Hypothenar eminence Muscles of the Lower Limb Muscles of the lower limb are much larger and more powerful than those of the upper limb.
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Muscle of the Thigh Name
Position
Origin
Insertion
Action
i) Quadriceps femoris
Front of thigh
- Ilium - Femur
Patella
- Extension of knee - Flexes hip
ii) Harm strings
Back of thigh
- Ischial tubeosity - Femur
iii) Sartorius
Crosses front of thigh
Anterior superior iliac spine
- Tibia at inner side
- Assist in flexion of hip, knee - Abduction and external rotation of hip
iv) Abductor of the hip
Inner side of thigh
Pubis and ischium
- Linea aspera - Medial condyle of femur
- Abducts the hip
Muscle of the leg and foot Name Position
- Tibia - Fibula
- Flexion of the knee - Extension of the hip
Origin
Insertion
Action
i) Gastrolnemius
The calf
- Condyles of the femus
Calcaneum
- Plantar flexion of the ankle raising the head
ii) Solens
The calf
- Tibia - Fibula
Calcaneum
- Plantar flexion of the ankle raising the head
iii) Tibialis anterior Side of the leg
- Tibia
- Tarsals - Metatarsals
- Dorsiflexion of the ankle raining the toe, inversion of foot
iv) Interosseous muscles
- Tibia
Between the metatarsals
Abducts and adducts digits
Foot
Step 5: Key Point (5 minutes)
There are three basic types of muscle in the human body: o Skeletal muscle (also called striated muscle)
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o Cardiac muscle (the muscle of the heart) o Visceral muscle (also called smooth muscle) General functions of muscle tissue o Initiation of contraction being stimulated autonomic nerve impulses –smooth and cardiac muscle tissue o Moving bones by skeletal muscle tissue o Covering body cavities o Protecting some body structures o Shaping of body (morphology)
Step 6: Evaluation (5 minutes)
What are the types of muscle tissue? What are the five functions of muscles? Which are the chief muscles of the body?
ASK students if they have any comments or need clarification on any points
References
Ross and Wilson (2006) Anatomy and Physiology in Health and Illness. (10th ed). Churchill - Livingstone Saladin S. K. (1998). Anatomy and Physiology. The Unity, form and Function.(1st ed). Mc Graw – Hill Boston Thibodean, G. A. and Patton K. J. (2001) Anatomy and Philosophy 3rd Edition Mosby Watson, R. (2001) Anatomy and Physiology for nurses. 11th Edition. Bailliere Tindall Watson, R. (2001) Anatomy and Physiology. The unity of form and function 1st Edition Mc Graw – Hill Boston Waugh, Ross and Wilson (2002), Anatomy and Physiology in Health and Illnesses, 9th Edition Churchill Livingstone; Sydney
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Handout 23.1: Muscles of the Body
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Session 24: Structure and Functions of the Skeletal System and Joints Total Session Time: 120 Minutes Prerequisite None Learning Tasks At the end of this session the students are expected to be able to: Describe the structure and functions of the skeletal system Describe the structure and functions of joints Resources Needed Flipcharts, Marker pens and Masking tape Black/white board and chalk/whiteboard markers Anatomical charts Anatomical models and atlas LCD and Computer Handout 24.1: The Human Skeleton Handout 24.2: The Human Skull Handout 24.3:The Vertebral Column Handout 24.4: Bones of the Lower and Upper Limbs Handout 24.5: Pelvic Bones Handout 24.6: The Joint SESSION OVERVIEW Step
Time
Activity/Method Presentation
Content
1
05 Minutes
Presentation of the Session and Learning Tasks
2
60 Minutes
3
45 Minutes
4
05 Minutes
Presentation
Key Points
5
05 Minutes
Presentation
Evaluation
Presentation, Structure and Functions of the Skeletal System Group Discussion Presentation, Structure and Functions of the Joints Group Discussion
SESSION CONTENT Step 1: Presentation of Session Title and Learning Tasks (5 minutes) READ or ASK students to read the learning tasks and clarify ASK students if they have any questions before proceeding
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Step 2: Structure and Functions of the Skeleton (60 minutes)
The skeleton is composed of 206 separate bones in the adult, and the cartilages and ligaments, which help to unite the bones at the joints.
Activity: Small Group Discussion ( 30 minutes) DIVIDE students into small manageable groups ASK students to work in groups and list the functions of the skeleton for 10 minutes ALLOW groups ask students to provide their response for 2 minutes each CLARIFY and summaries by using the contents below Types of Bones Bone is a strong and durable type of connective tissue consisting of: o Water o Organic constituents including osteoid (carbon containing part) and bone cells (25%) o Inorganic constituents – calcium phosphate 50% Bones are classified as long, short, irregular, flat and sesamoid o Long bones: These are longer than they are wide, examples includes the femur, tibia and fibula. o Flat bones: includes the ribs, shoulder blades, and most skull bones. o Irregular bones: Such as the bones of the face and the spine. o Sesamoid bones: It includes patella Structure of Skeletal Tissue Periostium: This is the outer covering of bones consisting blood vessels and nerves. Compact Bone: Mainly composed of calcium and phosphorus, is the hard outer layer of bone tissue. Cancellous Bone: Inside is a porous type of bone with many tiny spaces, helps to make the bones light. It includes; o Red Marrow: This fills the spaces in calcellous bone helps to produces red blood cells and some white blood cells. o Yellow Marrow: This is mainly composed of fat cells. Yellow bone marrow fills the shaft of the long bone making them light. o Cartilage: A strong plain tissue like hard rubbers are attached to some bones e.g. the end of the nose, and of its ribs. In babies and children’s bone consists of more cartilage, which is replaced by hard bone as the child grows. In children injured bones bends instead of breaking, and this is called a “Greenstick fracture” Ligaments are made of strong fibrous tissue and they hold bones together at the joints, allowing some movement. When ligaments around a joint are stretched and torn without injury to bone this is called a “sprain” NMT 04102 Anatomy and Physiology NTA Level 4, Semester 1
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Functions of the Bones Provision of the framework of the body. Giving attachment to muscles and tendons. Allowing movement of the body as a whole. Forming the boundaries of the cranial, thoracic and pelvic cavities. Protecting the internal organs. Production of blood cell formation. Storage of minerals especially calcium phosphate.
The bones of the skeleton are divided into groups:o The axial skeleton: Consisting of the skull, vertebral column, ribs and sternum. o The appendicular skeleton: Consist of bones of the upper limb, lower limb and pelvis. Refer Students to Handout 24.1: Diagram of Human Body
The Skull Consists of two parts the cranium (is like a box in which the brain is well protected) and the bones of the face. The cranium: Is made up of eight bones as follows; Frontal bone- forms the forehead and helps to protect the eyes. Parietal bones- one at each side of the top of the skull, joined in to the middle. Temporal bones- one on each side below the parietal bones these protect the inner parts of the ears Occipital bone- This forms the back of the head and part of the base of the skull, has a large opening for the spinal cord to pass through. Sphenoid- a hat shaped bone, which also forms part of the base of the skull. It has a little seat for the pituitary gland, and some holes for blood vessels and cranial nerves pass through. Ethmoid- forms the roof of the nose and in between the eyes. It has many small holes for the nerves of small to pass through the brain. The face has the following bones o 2 Nasal bones, which form the bridge of the nose. o 2 Lacrimal bones, near the eyes, which contain the rear ducts. o 2 Cheek bone(zygomatic bones); forms the prominences of the cheek and part of the flow and lateral wall of the orbital cavities o 1 Upper jawbones, with upper teeth. o 1Palate bones , which join with the upper jaw bones forming the hard palate o 2 inferior conchae, one in each side of wall of the nose. o 1 Vomer bone, which rests on the palate and helps to form the nasal septum o 1 Mandible: this is the lower jaw, the only movable bone of the skull o 2 Hyoid Bones, this is a horse shaped little bone in the upper part of the neck. The tongue muscle is attached to this bone. o The “angle of the jaw” on each side is important. o All the bones of the skull except the lower jaw are joined firmly together by fixed joints called “Sutures” o Some skull bones have hollow spaces called. “Sinuses” which connect with the nose and are filled with air. NMT 04102 Anatomy and Physiology NTA Level 4, Semester 1
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o Sinuses make the skull lighter, and help in the sound of the voice. ‘Sinusitis” is infection in these spaces. o The main sinuses are the frontal ones above the eyes, and large antrum sinuses, one in each of the upper jawbones. Refer Students to Handout 24.2: Diagram the Diagram of the Skull The Vertebral Column Spine or backbone is the central part of the skeleton. It supports the head and encloses the spinal cord. It consists of 33irregular bones called “Vertebrae” but some are fused together and so these are actually 26 separate bones forming the spine. The parts of the vertebral column are as follows: o 7 Cervical vertebrae column in the neck region. o The first two, called atlas and axis are important for nodding and turning the head o 12 Thoracic vertebrae at the back of the chest. o 5 Lumber vertebrae in the waist region. o These are big and strong for giving support. o 5 Sacral vertebrae are fused together to form the sacrum, a triangular shaped bone with a hollow anteriorly the sacrum helps to form the pelvis. o 4 Coccyx small vertebrae in the tail region are fused to form a small triangular bone called the coccyx attached to the lower part of the sacrum Refer Students to Handout 24.3: Diagram of the Vertebral Column The Thorax The Thorax or chest is formed by the sternum (Breast-bone) and costal cartilages in front, the ribs at the sides, and the twelve dorsal vertebral bones at the back. The Sternum Is a flat bone, shaped like a dagger pointing down-wards The tip consists of a cartilage known as the xiphisternum The upper part, like the handle is joined to the two collar bones. The costal cartilages are joined to the sides of the sternum and to the true ribs. The Ribs Are twelve pairs of the long curved bones The upper seven pairs are called true ribs, attached to the sternum by its costal cartilages. The next five pairs of ribs are called false ribs because they are joined by their cartilages to those of the ribs above and not directly to the sternum. The last two pairs are not connected to the sternum at all, and are called floating ribs Functions of the Thorax Protection for the heart, lungs, liver, stomach and spleen. Support for the bones of the shoulder girdle and for the breast. Important in respiration. Bones of the Upper Limbs Each upper limb consists of 32 bones; NMT 04102 Anatomy and Physiology NTA Level 4, Semester 1
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o The collar bone (clavicle) One on each side is a long bone with two curves. Its inner end is attached to the sternum, and outer end with the shoulder blade. The collar bone is easily felt at the lower and front part of the neck. It keeps the shoulder blade in place. When it is broken the shoulder drops forward and downwards. o The shoulder blade (scapula) One on each side at the upper and outer part of the back of the thorax. It is a large flat, triangular shaped bone with a ridge or spine at the back. It takes part in the shoulder joint. The 2 scapula and 2 collar bones form shoulder girdle o The humerus Is a long bone with a rounded head at the shoulders and a broad lower end at the elbow joint. o The radius and ulnar Bones of the forearm reach from the elbow joint to the wrist. o The wrist consists of eight carpal bones. These short bones are arranged in two rows, proximal and distal,with four bones in each row. o Metacarpal (bones of the hand) These five bones forms the palm of the hand These articulate with the distal row of carpal bones and with the proximal row of phalanges. o The phalanges are long bones. There are 14 phalanges The thumb has only two phalanges while the fingers have three each Refer Students to Handout 24.4: Diagram of the Upper and Lower Limb Bones of the Pelvis and Lower Limbs Each lower limb consists of 31 bones o One innominate or hip bone o One femur, the thigh bone, o One patella or knee cap, o One tibia o One fibula o Seven tarsal bones of the ankle, o Five metatarsal bones of the foot, o Fourteen phalanges of the toes. o The innominate bones, One on each side, join with the sacrum to form the pelvis. Besides protecting the pelvic organs, the pelvis supports the abdomen and provides the deep sockets for the hip joints. In the female, the true pelvis (lower part) is round so that the head, of the baby can pass through during delivery. In the male the true pelvis is long, narrow and heart – shaped. The innominate bone in a child is separated into three bones, which are fused together in the adult. Therefore the bone has three parts as follows:o Ilium NMT 04102 Anatomy and Physiology NTA Level 4, Semester 1
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o o
o o o o o
o
o
The upper flat part forms the false pelvis. Its upper ridge is called the iliac crest. Ischium The heavy lower part, which supports the body when sitting. Pubis The front part. The pubic bones from the joint called symphysis pubis. The femur (thigh bone) Is the longest and strongest bone in the body. The patella (kneecap) Is a small bone at the front of the knee joint. The tibia Is the long bone on the inner side of the lower 1eg The fibula Is a long thin bone on the outer side of the leg. The tarsal bones of the ankle These are seven short bones. The largest is the heel bone (calcaneus). The upper bone takes part in the ankle joint. The metatarsal bones Are five long bones in front of the feet They support the toes. The toe bones (phalanges) Are fourteen in number Like the finger bones, they are small long bones, two in the big toe and three in each of the other toe Refer Students to Handout 24.5: Diagram of the Pelvic Bones
Step 3: Structure and Functions of the Joints (45 minutes) Activity: Small Group Discussion ( 30 minutes) DIVIDE students into small manageable groups ASK students to work in groups and list the functions of the joints for 10 minutes ALLOW groups ask students to provide their response for 2 minutes each CLARIFY and summaries by using the contents below The Joints Is the point at which two or more bones meet Bones are held together at the joints by other connective tissue such as fibrous tissue, cartilage, ligaments and tendons. Muscles are the means by which all movement in the body takes place including the movement of bones at some of the joints.
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Types of Joints Fibrous joints o In which there is no movement. eg. The sutures of the skull. o The bones are joined together closely as though they were stitched (sutured) together. Cartilaginous joints o In which two bones are joined by a pad of fibrous cartilage, which allows slight movement o They are found in the vertebral column and pelvis. Synovial joints o Are freely movable, are found in the limbs and jaw. Ball and Socket joint o The round head of one bone fits into the cavity of another bone: e.g. shoulder and hip joints. Hinge joint o The only movements are flexion and extension. e.g. elbow, knee. Gliding joint o The bones glide on one another and allow fairly free movements. e.g. wrist and ankle joint. Pivot joint o Turning is the only movement e.g. the movement between the atlas and axis for turning the head. The Main Functions of the Joints Mobility Support Give the necessary support and security, the band-like ligament uniting the bones are strong and the extent of the movements is restricted. Refer Students to Handout 24.6: Diagram of the Joint
Step 4: Key Points (5 minutes)
The skeleton is composed of 206 separate bones in the adult, and the cartilages and ligaments, which help to unite the bones at the joints. Bones are classified as long, short, irregular, flat and sesamoid The main functions of the joints are; o Mobility o Support. o Give the necessary support and security, the band-like ligament uniting the bones are strong and the extent of the movements is restricted
Step 5: Evaluation (5 minutes)
Mention functions of the bones List bones of the upper limb Mention types of joints
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ASK students if they have any comments or need clarification on any points
Reference
Thibodean, G. A. & Patton, K. J. (2001) Anatomy and Philosophy.( 3rd ed). Mosby Roger W. (2002) Anatomy and Physiology for Nurses. 16th Edition, Bailliere Tindall Ross and Wilson (2006) Anatomy and Physiology in Health and Illness. 10th Edition Churchill - Livingstone Saladin S. K (1998) Anatomy and physiology. The unity form and function 1st Edition Mc Graw – Hill Boston Watson, R. (2001) Anatomy and Physiology for nurses. 11th Edition. Bailliere Tindall Watson, R. (2001) Anatomy and Physiology. The unity of form and function 1st Edition Mc Graw – Hill Boston Waugh, Ross and Wilson (2002), Anatomy and Physiology in Health and Illnesses, 9th Edition Churchill Livingstone; Sydney
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Handout 24.1: Human Skeleton
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Handout 24.2: Human Skull
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Handout 24.3: Vertebral Column
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Handout 24.4: Bones of the Leg and Hand
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Handout 24.5: Pelvic Bones
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Handout 24.6: Joint
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Session 25: Structure and Functions of the Eye Total Session Time: 60 Minutes Prerequisite None Learning Tasks At the end of this session the students are expected to be able to: Explain the structure of the eye Describe the functions of the eye Resources Needed Flipcharts, Marker pens and Masking tape Black/white board and chalk/whiteboard markers Anatomical charts Anatomical models and atlas LCD and Computer Hand out 25.1:The Orbit Handout 25.2: The Circulation Handout 25.3: The Eyelid and Lacrimal Apparatus Handout 25.4: The Eyeball SESSION OVERVIEW Step
Time
Activity/Method
Content
1
05 Minutes
Presentation
Presentation of Session and the Learning Tasks
2
45 Minutes
Presentation, Structure and Function of the Eye Group Discussion
3
05 Minutes
Presentation
Key Points
4
05 Minutes
Presentation
Evaluation
SESSION CONTENT Step 1: Presentation of Session Title and Learning Tasks (5 minutes) READ or ASK students to read the learning tasks and clarify ASK students if they have any questions before proceeding
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Step 2: Structure and Function of the Eye (45 minutes) Activity: Small Group Discussion ( 20 minutes) DIVIDE students into small manageable groups ASK students to work in groups and list the functions of the eye for 10 minutes ALLOW groups ask students to provide their response for 2 minutes each CLARIFY and summaries by using the contents below
The eye is an organ of the sense of sight situated in the orbital cavity It is almost spherical in shape and is about 2,5 cm in diameter The space between the eye and the orbital cavity is occupied by adipose tissue. The bony walls of the orbit and the fat help to protect the eye from injury. The main function of an eye is focusing of image on the retina Refer Students to Handout 25.1: The Orbit
The 7 Bones Surrounding the Eye (Orbit) The maxilla Zygomatic Frontal Ethmoid Lacrimal Sphenoid Palatine. Together they give the bony orbit the shape of a pyramid, with its wide base opening anteriorly onto the face, and its apex extending in a posteromedial direction. Completing the pyramid configuration is medial, lateral, superior, and inferior wall. Muscles of the Eye There are two groups of muscles within the orbit: o Extrinsic muscles of eyeball (extra-ocular muscles) involved in movements of the eyeball or raising upper eyelids; including the levator palpebrae superioris, superior rectus, inferior rectus, medial rectus, and lateral rectus, superior oblique and inferior oblique muscles. o Intrinsic muscles within including the ciliary muscle, the sphincter pupillae, and the dilator papillae muscles Of the seven muscles in the extrinsic group of muscles, one raises the eyelids, while the other six move the eyeball itself The movements of the eyeball, in three dimensions, are o Elevation-moving the pupil superiorly o Depression-moving the pupil inferiorly o Abduction-moving the pupil laterally o Adduction-moving the pupil medially o Internal rotation-rotating the upper part of the pupil medially (or towards the nose) NMT 04102 Anatomy and Physiology NTA Level 4, Semester 1
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o External rotation-rotating the upper part of the pupil laterally (or towards the temple). Blood and Nerve Supply of the Eye (Orbit) The arteries of the orbit are mainly from the ophthalmic artery, a branch of the internal carotid artery and the infraorbital artery, from the external carotid artery, also contributes to the supply of this region. In the orbit the ophthalmic artery gives off numerous branches as follows, o The lacrimal artery, which arises from the ophthalmic artery on the lateral side of the optic nerve, and passes anteriorly on the lateral side of the orbit, supplying the lacrimal gland, muscles, the anterior ciliary branch to the eyeball, and the lateral sides of the eyelid; There are two venous channels in the orbit, the superior and inferior ophthalmic veins o The superior ophthalmic vein begins in the anterior area of the orbit as connecting veins from the supra-orbital vein and the angular vein join together. o It passes across the superior part of the orbit, receiving tributaries from the companion veins to the branches of the ophthalmic artery and veins draining the posterior part of the eyeball. The inferior ophthalmic vein leaves the orbit posteriorly by, o Joining with the superior ophthalmic vein; o Passing through the superior orbital fissure on its own to join the cavernous sinus; or o Passing through the inferior orbital fissure to join with the pterygoid plexus of veins in the infratemporal fossa Because the ophthalmic veins communicate with the cavernous sinus, they act as a route by which infections can spread from outside to inside the cranial cavity.
Refer Students to Handout 25.2: The Circulation of the Eye Numerous nerves pass into the orbit and innervate structures within its bony walls They include: o The optic nerve [II] o The oculomotor nerve [III] o The trochlear nerve [IV] o The abducent nerve [VI] o Autonomic nerves. o Other nerves such as the ophthalmic nerve [V1] innervate orbital structures and then travel out of the orbit to innervate other regions.
Eyelids, Lacrimal Apparatus and Eye Ball The eyelids and lacrimal fluid, secreted by the lacrimal glands, protect the cornea and eyeball from injury and irritation. When closed, the eyelids cover the eyeball anteriorly, thereby protecting it from injury and excessive light.They also keep the cornea moist by spreading the lacrimal fluid. The space between the eyelids, when they are open, is the palpebral fissure. The layers of the eyelids, from anterior to posterior, consist of skin, subcutaneous tissue, voluntary muscle, the orbital septum, the tarsus, and conjunctiva. The upper and lower eyelids are basically similar in structure except for the addition of two muscles in the upper eyelid. The orbicularis oculi closes the eyelids and assists the flow of lacrimal fluid (tears).
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It has three parts: the palpebral part, which gently closes the eyelids; the lacrimal part, which passes posterior to the lacrimal sac, aiding drainage of tears; and the orbital part, which tightly closes the eyelids to protect the eyeballs against glare and dust. Orbicularis oculi is innervated by the facial nerve [VII] and closes the eyelids. The lacrimal apparatus is involved in the production, movement, and drainage of fluid from the surface of the eyeball. It is made up of the lacrimal gland and its ducts, the lacrimal canaliculi, the lacrimal sac, and the nasolacrimal duct. o Lacrimal glands secrete lacrimal fluid (tears). o Lacrimal ducts convey lacrimal fluid from the lacrimal glands to the conjunctival sac. o Nasolacrimal duct conveys the lacrimal fluid to the nasal cavity. Refer Student to Handout 25.3: The Eyelid and Lacrimal Apparatus
Eye Ball The globe shaped eyeball occupies the anterior part of the orbit. Its rounded shape is disrupted anteriorly, where it bulges outward. This outward projection represents about one sixth of the total area of the eyeball and is the transparent cornea. Posterior to the cornea and in order from front to back are the anterior chamber, the iris and pupil, the posterior chamber, the lens, the postrenal (vitreous) chamber, and the retina. Wall of the Eyeball Walls of the eyeball Surrounding the internal components of the eyeball are the walls of the eyeball. They consist of three layers: o An outer fibrous layer o A middle vascular layer o An inner retinal layer The outer fibrous layer consists of the sclera posteriorly and the cornea anteriorly; o The fibrous layer of the eyeball consists of two components-the sclera covers the posterior and lateral parts of the eyeball, about five-sixths of the surface, and the cornea covers the anterior part. o The sclera is an opaque layer of dense connective tissue that can be seen anteriorly through its conjunctival covering as the 'white of the eye'. The middle vascular layer consists of the choroid posteriorly and is continuous with the ciliary body and iris anteriorly. o The vascular layer of the eyeball consists of three continuous parts-the choroid, the ciliary body, and the iris from posterior to anterior. o The choroid is posterior and represents approximately two-thirds of the vascular layer. o It is a thin, highly vascular, pigmented layer consisting of smaller vessels adjacent to the retina and larger vessels more peripherally. o It is firmly attached to the retina internally and loosely attached to the sclera externally. The inner layer consists of the optic part of the retina posteriorly and the nonvisual retina that covers the internal surface of the ciliary body and iris anteriorly. o The inner layer of the eyeball is the retina.
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o
It consists of two parts; posteriorly and laterally is the optic part of the retina, which is sensitive to light, and anteriorly is the nonvisual part, which covers the internal surface of the ciliary body and the iris. Refer Students to Handout 25.4: The Eyeball
Step4: Key Points (5 minutes)
The eye is an organ of the sense of sight situated in the orbital cavity Seven bones contribute to the framework of each orbit are the maxilla, zygomatic, frontal, ethmoid, lacrimal, sphenoid, and palatine bones. There are two groups of muscles within the orbit. Extrinsic muscles of eyeball (extra-ocular muscles). Intrinsic muscles within the eyeball. The arteries of the orbit are mainly from the ophthalmic artery. The eyelids and lacrimal fluid, secreted by the lacrimal glands, protect the cornea and eyeball from injury and irritation.
Step 5: Evaluation (5 minutes)
Mention nerves supplying the orbit and eye. Mention chambers of the eye. Lacrimal gland secretes what type of secretion?
ASK students if they have any comments or need clarification on any points
References
Elsevier .D. et el: Gray’s Anatomy for students-www.studentsconsult.com. Retrieved on 15th November, 2011 Seeley R. R, Stephens T. D, Tate P. (2003) Anatomy and Physiology McGraw-Hill Thibodeau G. A. Patton K. T. (1999) Anatomy & Physiology Mosby, Inc. Von Hoffman Press, Inc
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Handout 25.1: The Orbit
Source: www.studentconsult.com
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Handout 25.2: The Circulation of the Eye
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Handout 25.3: The Eyelid and Lacrimal Apparatus
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Handout 25.4: The Eye Ball
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Session 26: Structure and Functions of the Ear Total Session Time: 120 Minutes Prerequesite None Learning Tasks At the end of this session the students are expected to be able to: Explain the structure of the ear Describe the functions of the ear Resources Needed Flipcharts, Marker pens and Masking tape Black/white board and chalk/whiteboard markers Anatomical charts Anatomical models and atlas LCD and Computer Handout 26.1: Parts of External Ear Handout 26.2: Parts of the Middle Ear Handout 26:3: Paarts of the Inner Ear Showing Cochlea SESSION OVERVIEW Step
Time
Activity/Method
Content
1
05 Minutes
Presentation
2
40 Minutes
3
65 Minutes
4
05 Minutes
Presentation
Key Points
5
05 Minutes
Presentation
Evaluation
Presentation of the Session and Related Tasks
Presentation, Structure of the Ear Brainstorm Presentation, Functions of the Ear Group Discussion
SESSION CONTENT Step 1: Presentation of Session Title and Related Tasks (5 minutes) READ or ASK students to read the related tasks and clarify ASK students if they have any questions before proceeding
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Step 2: Structure of the Ear (40minutes)
Ears are paired sensory organs comprising, o The auditory system, involved in the detection of sound, and o The vestibular system, involved with maintaining body balance/ equilibrium. The ear divides anatomically and functionally into three regions o The external ear. o The middle ear, and o The inner ear. All three regions are involved in hearing. Only the inner ear functions in the vestibular system. The external ear (or pinna, the part you can see) o Serves to protect the tympanic membrane (eardrum), as well to collect and direct sound waves through the ear canal to the eardrum. About 1¼ inch long, the canal contains modified sweat glands that secrete cerumen, or earwax. o Too much cerumen can block sound transmission. The middle ear, o Separated from the external ear by the eardrum, is an air-filled cavity (tympanic cavity) carved out of the temporal bone. o It connects to the throat/nasopharynx via the Eustachian tube. o This ear-throat connection makes the ear susceptible to infection (otitis media). o The eustachian tube functions to equalize air pressure on both sides of the eardrum. o Normally the walls of the tube are collapsed. o Swallowing and chewing actions open the tube to allow air in or out, as needed for equalization o Equalizing air pressure ensures that the eardrum vibrates maximally when struck by sound waves. o Adjoining the eardrum are three linked, movable bones called ossicles, which convert the sound waves striking the eardrum into mechanical vibrations. o The smallest bones in the human body, the ossicles are named for their shape. o The hammer (malleus) joins the inside of the eardrum. o The anvil (incus), the middle bone, connects to the hammer and to the stirrup (stapes). o The base of the stirrup, the footplate, fills the oval window which leads to the inner ear. The inner ear o Consists of a maze of fluid-filled tubes, running through the temporal bone of the skull. The bony tubes, the bony labyrinth, are filled with a fluid called perilymph. o Within this bony labyrinth is a second series of delicate cellular tubes, called the membranous labyrinth, filled with the fluid called endolymph. o This membranous labyrinth contains the actual hearing cells, the hair cells of the organ of Corti. o There are three major sections of the bony labyrinth, The front portion is the snail-shaped cochlea, which functions in hearing. The rear part, the semicircular canals, helps maintain balance. Interconnecting the cochlea and the semicircular canals is the vestibule, containing the sense organs responsible for balance, the utricle and saccule
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o The inner ear has two membrane-covered outlets into the air filled middle ear, the oval window and the round window. o The oval window sits immediately behind the stapes, the third middle ear bone, and begins vibrating when "struck" by the stapes. o This sets the fluid of the inner ear sloshing back and forth. o The round window serves as a pressure valve, bulging outward as fluid pressure rises in the inner ear. Nerve impulses generated in the inner ear travel along the vestibulocochlear nerve (cranial nerve VIII), which leads to the brain. o This is actually two nerves, somewhat joined together, the cochlear nerve for hearing and the vestibular nerve for equilibrium. Refer students to Handout 26.1: Structure of the External Ear
Step 3: Functions of the Ear (65 minutes) Activity: Small Group Discussion ( 30 minutes) DIVIDE students into small manageable groups ASK students to work in groups and list the functions of the ear for 10 minutes ALLOW groups ask students to provide their response for 2 minutes each CLARIFY and summaries by using the contents below The Functions of the Ear Hearing Balance Mechanism of Hearing Hearing (or audition) is one of the traditional five senses. It is the ability to perceive sound by detecting vibrations via an organ such as the ear. The inability to hear is called deafness. In humans and other vertebrates, hearing is performed primarily by the auditory system, vibrations are detected by the ear and transduced into nerve impulses that are perceived by the brain (primarily in the temporal lobe). Like touch, audition requires sensitivity to the movement of molecules in the world outside the organism. All sounds (music, voice, a mouse-click, etc.) send out vibrations, or sound waves. Sound waves do not travel in a vacuum, but rather require a medium for sound transmission, e.g. air or fluid. What actually travels are alternating successions of increased pressure in the medium, followed by decreased pressure. These vibrations occur at various frequencies, not all of which the human ear can hear. The cochlea is filled with a watery liquid, which moves in response to the vibrations coming from the middle ear via the oval window. As the fluid moves, thousands of "hair cells" are set in motion, and convert that motion to electrical signals that are communicated via neurotransmitters to many thousands of nerve cells. NMT 04102 Anatomy and Physiology NTA Level 4, Semester 1
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These primary auditory neurons transform the signals into electrical impulses known as action potentials, which travel along the auditory nerve to structures in the brainstem for further processing. In hearing, air-borne sound waves funnel down through the ear canal and strike the eardrum, causing it to vibrate. The vibrations are passed to the small bones of the middle ear (ossicles), which form a system of interlinked mechanical levers; first, vibrations pass to the malleus (hammer), which pushes the incus (anvil), which pushes the stapes (stirrup). The base of the stapes rocks in and out against the oval window; this is the entrance for the vibrations. The stapes agitates the perilymph of the bony labyrinth. At this point, the vibrations become fluid borne. The perilymph, in turn, transmits the vibrations to the endolymph of the membranous labyrinth and, thence, to the hair cells of the organ of Corti. It is the movement of these hair cells which convert the vibrations into nerve impulses. The round window dissipates the pressure generated by the fluid vibrations, thus serves as the release valve; it can push out or expand as needed. The nerve impulses travel over the cochlear nerve to the auditory cortex of the brain, which interprets the impulses as sound. The cochlear duct is supported on three sides by a rich bed of capillaries and secretory cells (the stream vascularis), a layer of simple Squamous epithelial cells (Reissner's membrane), and the basilar membrane, on which rests the receptor organ for hearing - the organ of Corti. Refer students to Handout 26.2: Parts of Inner Ear
Physiology of Balance The semicircular canals and vestibule function to sense movement (acceleration and deceleration) and static position. The three semicircular canals lie perpendicular to each other, one to sense movement in each of the 3 spatial planes. At the base of the canals are movement hair cells, collectively called the crista ampullaris. Depending on the plane of movement, the endolymph flowing within the semicircular canals stimulates the appropriate movement hair cells. Static head position is sensed by the vestibule, specifically, its utricle and saccule, which contain the position hair cells. Different head positions produce different gravity effects on these hair cells. The utricle, or utriculus, along with the saccule is one of the two otolith organs located in the vertebrate inner ear. These use small stones and a viscous fluid to stimulate hair cells to detect motion and orientation While the semicircular canals respond to rotations, the otolithic organs sense linear accelerations. We have two on each side, one called utricle, the other saccule The utricle contains mechanoreceptors called hair cells that distinguish between degrees of tilting of the head, thanks to their apical cilia set-up. These are covered by otolith which, due to gravity, pull on the cilia and tilt them. The hair cells for both position and movement create nerve impulses. NMT 04102 Anatomy and Physiology NTA Level 4, Semester 1
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These impulses travel over the vestibular nerve to synapse in the brain stem, cerebellum, and spinal cord. No definite connections to the cerebral cortex exist. Instead, the impulses produce reflex actions to produce the corrective response.e.g. a sudden loss of balance creates endolymph movement in the semicircular canals that triggers leg or arm reflex movements to restore balance The cavity of the utricle communicates behind with the semicircular ducts by five orifices. The ductus utriculosaccularis comes off of the anterior wall of the utricle and opens into the ductus endolymphaticus.
Step 4: Key Points (5minutes)
Ears are paired sensory organs comprising of auditory system, involved in the detection of sound, and vestibular system, involved with maintaining body balance/ equilibrium. The semicircular canals and vestibule function to sense movement (acceleration and deceleration) and static position. While the semicircular canals respond to rotations, the otolithic organs sense linear accelerations. We have two on each side, one called utricle, and the other saccule.
Step 5: Evaluation (5 minutes)
Define Ear Mention the parts of the ear. Briefly explain the Physiology of balance
ASK students if they have any comments or need clarification on any points
References
Elsevier .Drake et el: Gray’s Anatomy for students-www.studentsconsult.com. Retrieved on 15th November, 2011 Moore, Keith, Agur, Anne (2007). Essential Clinical Anatomy. (3rd ed). Lippincott William & Wilkins Standring (2005), Gray’s Anatomy. (39th ed). New York. Elsevier LTD Williams & Wilkins Moore, Keith L.; Agur, Anne M. R. (2007): Essential Clinical Anatomy. (3rd ed). Lippincott
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Handout 26.1: Structure of the External Ear
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Source: Standing 2005
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Handout 26.2: Parts of Inner Ear
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Handout 26.3: Parts of the Inner ear Showing the Cochlear
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