YEREVAN STATE MEDICAL UNIVERSITY AFTER M. HERATSI NORMAL PHYSIOLOGY HANDOUT FOR FOREIGN STUDENTS YEREVAN – 2008 YEREVAN STATE MEDICAL UNIVERSITY AFTER M. HERATSI Ter-Markosyan A.S., Harutunyan K.R., Arakelyan K.P., Avetisyan K.A. NORMAL PHYSIOLOGY HANDOUT FOR FOREIGN STUDENTS Editor: professor Khudaverdyan D.N. YEREVAN Publishing house of the Yerevan State Medical University after M. Heratsi 2008 UDC 612 (07) Normal Physiology (Handout for Foreign Students) / Ter- Markosyan A.S., Harutunyan K.R., Arakelyan K.P., Avetisyan K.A. -Yerevan, YMSU, 2008 - 330 pp. Editor: professor Khudaverdyan D.N. Reviewers: Khanbabyan M.V., Professor of the Human and Animals’ Physiology Department of the Yerevan State Pedagogical University after Kh. Abovyan, Doctor of Medical Sciences Hakobyan N.S., Professor of the Human and Animals’ Physiology Department of the Yerevan State University, Doctor of Biological Sciences English language editor: Bisharyan M.N. In the handout are represented the main parts of physiology, which correspond to the syllabus of the normal physiology course. It will be useful for foreign students of medical and biological high schools. The handout is adopted by Methodical Comission for Foreign Students of theYerevan State Medical University after M. Heratsi. ISBN 978-9994-40-78-7 © Dpt. of Physiology of YSMU, 2008 ºðºì²ÜÆ Ø. кð²òàô ²Üì²Ü äºî²Î²Ü ´ÄÞÎ²Î²Ü Ð²Ø²Èê²ð²Ü î»ñ-سñÏáëÛ³Ý ².ê., гñáõÃÛáõÝÛ³Ý ø.è., ²é³ù»ÉÛ³Ý Î.ä., ²í»ïÇëÛ³Ý Î.². ÜàðØ²È üƼÆàÈà¶Æ² àôêàôØܲغÂà¸²Î²Ü ÒºèܲðÎ ²ðî²ê²ÐزÜòÆ àôê²ÜàÔܺðÆ Ð²Ø²ð ÊÙµ³·Çñ` åñáý»ëáñ ¸. Ü. Êáõ¹³í»ñ¹Û³Ý ºðºì²Ü ºñ¨³ÝÇ Ø.лñ³óáõ ³Ýí. ä»ï³Ï³Ý µÅßÏ³Ï³Ý Ñ³Ù³Éë³ñ³ÝÇ Ññ³ï³ñ³ÏãáõÃÛáõÝ 2008 Ðî¸ 612 (07) ¶ Ø ¸ 28.903 ó73 Ý 937 Ý 937 ÜáñÙ³É ýǽÇáÉá·Ç³ (Ò»éݳñÏ ³ñï³ë³ÑÙ³ÝóÇ áõë³ÝáÕÝ»ñÇ Ñ³Ù³ñ) / î»ñ-سñÏáëÛ³Ý ².ê., гñáõÃÛáõÝÛ³Ý ø.è., ²é³ù»ÉÛ³Ý Î. ä., ²í»ïÇëÛ³Ý Î. ². - ºñ., ºä´Ð, 2008 – 330¿ç: ÊÙµ³·Çñ` åñáý»ëáñ ¸. Ü. Êáõ¹³í»ñ¹Û³Ý ¶ñ³ËáëÝ»ñ` 1. ºñ¨³ÝÇ Ê.²µáíÛ³ÝÇ ³Ýí³Ý å»ï³Ï³Ý Ù³Ýϳí³ñÅ³Ï³Ý Ñ³Ù³Éë³ñ³ÝÇ Ø³ñ¹áõ ¨ ϻݹ³ÝÇÝ»ñÇ ýǽÇáÉá·Ç³ÛÇ ³ÙµÇáÝÇ åñáý»ëáñ, µÅßÏ³Ï³Ý ·ÇïáõÃÛáõÝÝ»ñÇ ¹áÏïáñ ʳݵ³µÛ³Ý Ø. ì. 2. ºñ¨³ÝÇ å»ï³Ï³Ý ѳٳÉë³ñ³ÝÇ Ø³ñ¹áõ ¨ ϻݹ³ÝÇÝ»ñÇ ýǽÇáÉá·Ç³ÛÇ ³ÙµÇáÝÇ åñáý»ëáñ, Ï»Ýë³µ³Ý³Ï³Ý ·ÇïáõÃÛáõÝÝ»ñÇ ¹áÏïáñ гÏáµÛ³Ý Ü.ê. ²Ý·É»ñ»Ý É»½íÇ ËÙµ³·Çñ` ´Çß³ñÛ³Ý Ø. Ü. Ò»éݳñÏáõÙ Ý»ñϳ۳óí³Í »Ý ýǽÇáÉá·Ç³ÛÇ ÑÇÙÝ³Ï³Ý µ³ÅÇÝÝ»ñÁ, áñáÝù ѳٳå³ï³ë˳ÝáõÙ »Ý ÝáñÙ³É ýǽÇáÉá·Ç³ÛÇ ¹³ë³í³Ý¹Ù³Ý Íñ³·ñÇÝ: Ò»éݳñÏÝ û·ï³Ï³ñ ÏÉÇÝÇ µÅßÏ³Ï³Ý ¨ Ï»Ýë³µ³Ý³Ï³Ý áõÕÕí³ÍáõÃÛáõÝ áõÝ»óáÕ ´àôÐ-»ñÇ ³ñï³ë³ÑÙ³ÝóÇ áõë³ÝáÕÝ»ñÇ Ñ³Ù³ñ: Ò»éݳñÏÁ ѳëï³ïí³Í ¿ ºä´Ð ²ñï³ë³ÑÙ³ÝóÇ áõë³ÝáÕÝ»ñÇ áõëáõÙݳٻÃá¹³Ï³Ý Ñ³ÝÓݳÅáÕáíÇ ÏáÕÙÇó: ¶ Ø ¸ 28.903 ó73 ISBN 978-99941-40-78-7 © ºä´Ð ýǽÇáÉá·Ç³ÛÇ ³ÙµÇáÝ, 2008 CONTENTS Introduction 10 Chapter 1. Physiology of Excitable Tissues 16 1.1.General Physiology of Excitable Tissues 16 Bioelectrical phenomena. Historical outline 17 Resting potential 19 Action potential 22 Passive and active transport of ions 25 Changes of excitability during excitation 27 Comparative characteristics of the local (LP) and action (AP) potentials 28 Parameters of excitation 29 The effect of direct current on excitable tissues. The law of stimulation polarity. Physiological electrotone 32 1.2.Physiology of Nerve Fibre 34 Classification of nerve fibres 34 Laws of excitation conduction in the nerve 36 Mechanism of impulse conduction in the nerve fibres 37 1.3.Physiology of Neuromuscular Transmission 39 Mechanism of excitation transmission in neuromuscular synapse 40 The properties of the neuromuscular (chemical) synapse 42 1.4.Physiology of Muscles 43 Skeletal Muscles 44 Types of the muscle contraction 45 Muscle single contraction 45 Tetanus and summation of contractions 46 Ultrastructure of myofibrils 47 Mechanisms of muscle contraction and relaxation 49 Work and force of the muscle 51 Some peculiarities of smooth muscles 52 Chapter 2. Physiology of the Central Nervous System 53 2.1.General Physiology of the Central Nervous System 53 Structural and functional elements of the CNS. Neuron and glia 53 6 Interneuronal communications 59 Reflector character of the CNS activity 62 Inhibition in the CNS 64 Nervous centre’s properties 69 Principles of coordination in the CNS 73 2.2.Special Physiology of the Central Nervous System 79 Spinal cord 79 Hindbrain 84 Midbrain 87 Cerebellum 89 Diencephalon. Thalamus and hypothalamus 92 Chapter 3. Higher Nervous Activity 97 3.1.Conditional and Unconditional Reflexes 97 Rules for building conditional reflexes 99 Components of unconditional and conditional reflexes 99 Mechanisms of conditional reflex producing 100 3.2.Cortical Inhibition 102 Analysis and synthesis 104 Mutual induction of excitation and inhibition 105 3.3. Types of the Higher Nervous Activity 105 3.4. Sleep 107 Chapter 4. Physiology of the Vegetative Nervous System 115 General characteristics of the vegetative nervous system 116 Comparative analysis of the somatic and the vegetative nervous systems 120 Properties of the vegetative ganglia (synapses) 121 Mechanism of impulse conduction in vegetative synapses, their mediators 123 Vegetative reflexes 127 Chapter 5. Physiology of the Endocrine System 128 5.1. General Characteristics of the Endocrine Glands 129 Structure, properties and action mechanism of hormones 131 5.2. The Hypothalamo-hypophysial System 136 The hypothalamo – extrahypophysial system 139 The hypothalamo- neurohypophysial system 140 The hypothalamo-adenohypophysial system 141 5.3. Special Physiology of the Endocrine Glands 146 7 Physiology of the thyroid gland 145 Physiology of the parathyroid glands 148 Physiology of the adrenal glands 150 Physiology of the sex glands (gonads) 154 Physiology of the pancreas 159 Chapter 6. Physiology of the Blood System 162 6.1. Internal Medium of the Body 162 Composition and properties of blood 162 Composition and properties of lymph 166 6.2. Blood Formed Elements 168 Erythrocytes 168 Leucocytes 172 Thrombocytes (platelets) 176 6.3. Blood Coagulation 177 Vascular-platelet hemostasis 178 Coagulation hemostasis 179 After-phase of hemostasis 180 Anticoagulation mechanisms 180 Regulation of blood clotting 181 6.4. Blood Groups and Rh-factor 183 Blood groups 183 Rhesus-factor 185 Chapter 7. Physiology of the Cardio-vascular System 187 7.1. Physiology of the Heart 187 The heart conductive system and automatism 188 The phase analysis of the heart cycle 194 Methods of investigation of the heart activity 196 Cardiac muscle physiological peculiarities 201 Regulation of the heart functional activity 204 7.2. Physiology of the Vascular System 217 General principles of the structure and functioning of the vascular system. 217 The main indices of hemodynamics 220 Arterial pulse 226 Regulation of blood circulation 229 Chapter 8. Physiology of the Respiratory System 235 External respiration 235 Lung volumes 241 8 Lung ventilation 243 Gas exchange in alveoli and tissues 244 Gas transport by the blood 249 Regulation of respiration 252 Respiration under various circumstances 260 Chapter 9. Physiology of the Digestive System 266 Functions of the digestive system and types of digestive processes 266 Digestion in the mouth 268 Digestion in the stomach 273 Digestion in the small intestine 280 Digestion in the large intestine 288 Absorption 291 Motor activity of the gastro-intestinal tract 293 Periodic activity of the digestive organs 298 Chapter 10. Metabolism of Energy and Thermoregulation 301 10.1. Metabolism of Energy 301 10.2. Thermoregulation 307 Chapter 11. Physiology of the Excretory System 311 Morpho-functional characteristics of the kidneys 311 Kidney blood supply 314 Formation of urine 316 Urine excretion and micturition 325 Endocrine function of the kidney 325 Regulation of kidney function 327 Literature 329 9 Introduction The term “Physiology” generates from the Greek words – physics (nature) and logy (studying). Physiology studies the main processes of alive organism’s activity, its organs, tissues, cells and their structural elements in conjunction with external environment. So the goal of physiology is to reveal the organs’ functions, intra-organic connections, and interactions between the organism and surrounding medium which is the necessary condition for its existence. Physiology and other disciplines. Physiology is in close connection with other sciences and firstly with such morphological disciplines as anatomy, histology, cytology, since structure and function are interconnected and determine each other. As during the activity of cells the convection of substances and energy proceeds, physiology is based on the rules of physics and chemistry that brings to the development of separate disciplines – biophysics and biochemistry. Physiology is the theoretical base of general pathology and clinical medicine. Without deep comprehension of the heart, lungs, digestive system and other organs’ function it is impossible to reveal the pathology. Achievements of physiology are of great use in medicine, e.g. Pavlov’s works on the physiology of the digestive tract organs serve as a basis for gastroenterology and dietology. In its turn medicine gives a clinical material for physiological study, e.g. different clinical manifestations of endocrine impairments enable the further study of the inner secretion glands’ function. 10 The connection of physiology and cybernetics is the point of interest and helps to reveal the general principles of function regulation of their interaction using artificial modelling of biological phenomenon.