LECTURE NOTES For Health Science Students Physiology Part I Yekoye Abebe, Bhardwaj, G.P., Habtamu Mekonnen University of Gondar Jimma University In collaboration with the Ethiopia Public Health Training Initiative, The Carter Center, the Ethiopia Ministry of Health, and the Ethiopia Ministry of Education 2006 Funded under USAID Cooperative Agreement No. 663-A-00-00-0358-00. Produced in collaboration with the Ethiopia Public Health Training Initiative, The Carter Center, the Ethiopia Ministry of Health, and the Ethiopia Ministry of Education. Important Guidelines for Printing and Photocopying Limited permission is granted free of charge to print or photocopy all pages of this publication for educational, not-for-profit use by health care workers, students or faculty. All copies must retain all author credits and copyright notices included in the original document. Under no circumstances is it permissible to sell or distribute on a commercial basis, or to claim authorship of, copies of material reproduced from this publication. ©2006 by Yekoye Abebe, Bhardwaj, G.P., Habtamu Mekonnen All rights reserved. Except as expressly provided above, no part of this publication may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying, recording, or by any information storage and retrieval system, without written permission of the author or authors. This material is intended for educational use only by practicing health care workers or students and faculty in a health care field. PREFACE We have prepared lecture note that fits the academic curriculum designed for the students of Health Sciences in Ethiopia. This lecture note has two parts. Part one includes the following five chapters: Principles of physiology, Excitable tissues (nerve and muscle), physiology of blood, Cardiovascular physiology and Respiratory physiology; Part two contains the following seven chapters: physiology of the renal system, physiology of the gastrointestinal system, physiology of the endocrine system, physiology of the reproductive system, Neurophysiology, physiology of the Special senses and the Autonomic nervous system. i ACKNOWLEDGEMENTS We are grateful to some students and teachers who have commented favorably on the clarity of the writing, and the emphasis on the core aspects of physiology. We express sincere appreciation to the secretaries for meticulous computer type settings of the teaching material. SEPTEMBER, 2004 GONDAR , ETHIOPIA ii TABLE OF CONTENTS Preface .................................................................................. .................. i Acknowledgement .................................................................. ...................ii Table of contents ................................................................... ................. iii List of tables ........................................................................... ................. v CHAPTER ONE: GENERAL PRINCIPLES OF HUMAN PHYSIOLOGY . 1 Introduction ............................................................................ ................. 2 Composition of the body ........................................................ .................. 4 Homeostasis .......................................................................... .................. 6 Cellular Physiology ................................................................ ............... 10 Organelles ............................................................................. ................ 13 Membrane transport ............................................................... ................ 26 Intercellular communication and signal transduction .............. ................ 33 Homeostatic Control .............................................................. ................ 41 Feedback mechanisms .......................................................... ................ 43 Cellular adaptation ................................................................. ................ 53 CHAPTER TWO: EXCITABLE TISSUE: NERVE AND MUSCLE .......... 60 Membrane potential .............................................................. ................ 60 Neurons ................................................................................. ................ 63 The action potential ................................................................ ................ 68 Neuromuscular junction/synapse ........................................... .............. 75 Physiology of the neuromuscular junction .............................. ................ 76 Mechanism of action of acetylcholine .................................... ................ 76 Chemical neurotransmitter ..................................................... ................ 79 Skeletal muscle ...................................................................... ................ 80 Excitation-Contraction Coupling ............................................. ................ 84 Smooth and cardiac muscle ................................................... ................ 92 CHAPTER THREE: CARDIOVASCULAR SYSTEM ............. ............... 99 The blood ............................................................................... ................ 99 iii Erythrocytes ........................................................................... .............. 104 Hemoglobin molecule: structure and function ....................... .............. 106 Blood Groups & Blood Transfusion ........................................ .............. 113 Leukocytes ............................................................................. .............. 118 Neutrophills ............................................................................ .............. 124 Lymphocytes .......................................................................... .............. 126 The body defenses ................................................................ .............. 129 Hemostasis ............................................................................ .............. 132 Disorders of hemostasis ........................................................ .............. 138 The Heart ................................................................................ .............. 141 Innervations of the heart ........................................................ .............. 146 Electrocardiogram .................................................................. .............. 152 Venous system ...................................................................... .............. 167 Cardiac output ....................................................................... .............. 171 Microcirculation ...................................................................... .............. 184 Measurement of arterial pressure .......................................... .............. 188 Regulation of flow through blood vessels ............................... .............. 193 Circulatory shock ................................................................... .............. 209 Hypertension .......................................................................... .............. 213 Glossary ................................................................................. .............. 221 CHAPTER FOUR: THE RESPIRATORY SYSTEM ............... .............. 229 Function of the respiratory system ......................................... .............. 230 Functional anatomy of the respiratory system ....................... .............. 230 Pulmonary blood flow ............................................................. .............. 232 Lung volumes and capacities ................................................. .............. 232 Mechanics of breathing .......................................................... .............. 236 Diffusion of gases .................................................................. .............. 241 Gas transport in tissues ......................................................... .............. 245 Control of breathing ............................................................... .............. 258 Hypoxia .................................................................................. .............. 264 Disorders of the respiratory system ....................................... .............. 268 iv LIST OF TABLES Table 1. Elements in the human body .................................... .................. 5 Table 2. Components of body system .................................... .................. 6 Table 3. Concentration and permeability of ions responsible for membrane potential in a resting nerve cell ................................ ................ 61 Table 4. Concentration and electrical gradients ..................... ................ 61 Table 5. Fiber diameter and speed of signal conduction ........ ............... 66 Table 6. Blood constituents and their function ....................... .............. 101 Table 7. Elements of the Blood .............................................. .............. 102 Table 8. Plasma components and other characters ............... ............. 103 Table 9. Important carrier proteins of plasma ........................ ............ 104 Table 10. The major normal variants of hemoglobin ............... .............. 107 Table 11. Summery of ABO system ....................................... ............. 113 Table 12. ABO Blood groups: genotype and phenotype ........ ............. 115 Table 13. Choosing ABO-compatible