Principles of Physiology

About the Book

The diverse concepts of physiology have been presented in a lucid language which makes the book student-friendly.
Updated information and interesting tit-bits have been included.
New diagrams, innovative flowcharts and useful tables have been incorporated.
Colored boxes have been used to highlight interesting information as well as advanced concepts.
All the important Abbreviations have been added at the end of the book.
Manual of Practical Physiology and MCQs Book:
Provides around 750 MCQs with answers and hints.
A concise coverage of Practical Physiology.
A list of most commonly asked questions of first Professional MBBS Examination.
New diagrams and useful tables have been incorporated.
Colored boxes have been used to highlight important information.

About the Author

Debasis Pramanik MD (Cal)

Table of Contents:
SEC-1—GENERAL PHYSIOLOGY 1–42 Chapter 1 : Structure of a cell 3 • Cell membrane (fluid mosaic model) 3 • Nucleus 6 • Ribosomes 7 • Endoplasmic reticulum 7 • Golgi apparatus 8 • Mitochondria 8 • Lysosomes 9 • Peroxisomes 9 • The filaments 9 • Intracellular motor proteins (kinesin, dynein and myosin) 10 • Intercellular junctions 11 • Gap junctions 12 • Extracellular matrix (connective tissue) and related diseases 13 Chapter 2 : Genes and protein synthesis 16 • Dominant and recessive gene 16 • Genetic code 17 • Transcription (synthesis of mrna) 17 • Exon and intron 19 • Translation 19 • Posttranslational modification 21 • Protein secretion 21 • Regulation of protein synthesis 21 •Cell division 22 •Cell cycle 22 • Steps of cell division 23 • Mutation 24 • Effects of mutation on cell function 24 • Cancer 25 • Factors predisposing to cancer 25 • Oncogenes and tumor suppressor genes 26 • Hormones and cancer 26 • Apoptosis 26 Chapter 3 : Transport proteins in cell membrane 28 • Ion channels 28 • Pumps 30 • Carriers 30 Chapter 4 : Transport across cell membranes 32 • Diffusion 32 • Osmosis 34 • Active transport 37 • Vesicular transport 40 • Homeostasis 41 SEC-2—NERVE MUSCLE PHYSIOLOGY 43–82 Chapter 5 : Resting membrane potential 45 • Cause of the rmp 45 Chapter 6 : Action potential 50 • Catelectrotonus, anelectrotonus and local response 53 • Refractory period 54 •Threshold stimulus 55 • Strength-duration curve 55 • Rheobase 55 • Utilization time 55 • Chronaxie 55 • Accommodation 56 • All-or-none law 56 • Propagation of action potential 56 • Saltatory conduction57 •Compoundactionpotential 57 •Biphasic action potential 57 • Injury potential 58 • Effect of extracellular ion concentration on action potential 58 Contents xii Principles of Physiology Chapter 7 : Neuromuscular junction 60 Mechanism of neuromuscular transmission61 •Difference between transmission at the synapse and at the neuromuscular junction 62 • Agents affecting neuromuscular transmission 62 • Myasthenia gravis 63 • Lambert-Eaton syndrome 64 • Denervation hypersensitivity 64 Chapter 8 : Mechanism of muscle contraction 65 •The skeletal muscle 65 •The myofibrils 65 •The thick filament 66 • The thin filament 66 • Banding pattern 67 • The sarcotubular system 68 • Excitation-contraction coupling 69 • Cardiac muscle has the following differences from skeletal muscle 73 • Smooth muscle has the following differences from other types of muscle tissue 74 Chapter 9 : Properties of skeletal muscle 77 • Length-tension relationship in skeletal muscle 77 • Chemical events in skeletal muscle 79 • Phosphorylcreatine 79 • Aerobic and anaerobic glycolysis 79 • Oxygen debt 80 • Motor unit and size principle 81 SEC-3—HEMATOLOGY 83–153 Chapter 10 : Functions of blood and blood volume 85 • Functions of blood 85 • Determination of blood volume 85 Chapter 11 : Composition of blood and plasma proteins 87 • Composition of blood 87 • The plasma proteins 88 • Brief description of individual plasma protein 89 • Plasmapheresis 90 • Function of plasma proteins 90 • Colloidal osmotic tension, starling hypothesis and edema 91 • Edema 92 • C-reactive protein 93 Chapter 12 : The red blood cells 94 • Morphology of rbc 94 • Metabolism of RBC 95 • Function of rbc 96 • Hereditary spherocytosis and osmotic fragility 96 • The general scheme of development of blood cells 96 • Cell renewal 97 •Erythropoiesis 97 • Stepsof erythropoiesis 98 •Factorsinfluencing erythropoiesis 99 • Pernicious anemia 102 Chapter 13 : Hemoglobin 103 • Structure of hemoglobin 103 • Synthesis of hemoglobin 104 • Fetal hemoglobin (hbf) 104 • Sickle cell anemia 104 • Sickle cell Contents xiii trait 104 • Thalassemia 104 • Hb-compounds and derivatives 105 • Fate of hemoglobin 106 • Anemia 108 • Anemia due to blood loss 110 • Microcytic anemia 110 • Fe-deficiency anemia 110 •Aplastic anemia 110 • Hemolytic anemia 111 • Esr or erythrocyte sedimentation rate 111 • Mechanism of erythrocyte sedimentation (Rouleaux formation) 112 • Significance of esr 113 Chapter 14 : White blood cells 114 • Morphological features 114 • Pools of neutrophils 116 • Development of neutrophils 116 • Function of wbc 116 • Variation in wbc count and some important clinical terms 120 • Res or tissue macrophage system 121 • Lymph 121 Chapter 15 : Platelets and blood coagulation 123 • Hemostasis 123 • Platelets 123 • Morphological characteristics 123 • Contents 124 • Functions of platelets 124 • Formation of platelet plug 125 • Antithrombotic role of aspirin 126 • Blood coagulation 126 • Serum 128 • Anticlotting mechanism 129 • Vitamin K-dependent clotting factors 130 • Anticoagulants 131 • Tests for defective hemostasis 131 • Coagulation disorders 133 Chapter 16 : Blood group 136 •Introduction 136 •ABO blood group system 136 •Rh blood group 137 • Grouping and cross-matching, universal donor and recipient 137 • Preservation injuries 138 • Hazards of blood transfusion 139 • Hemolytic disease of newborn 140 • Importance of blood group 141 Chapter 17 : Immunity 142 • Introduction 142 • Specific immunity 142 • B and T lymphocytes 143 • K/NK cells 143 • Role of macrophages in immunity 143 •Mast cells 144•MHCproteins(hlaantigens) 144 •Tcellreceptor and immunological synapse 144 • Cell-mediated immunity 145 • Delayed type of hypersensitivity 145 • Cell-mediated cytotoxicity 145 • Activation of B cells 146 • General structure of immunoglobulins 146 • The individual immunoglobulins 147 • Genetic diversity of immunoglobulins 148 • Different actions of antibodies 148 • Lymphokines, cytokines and interleukins (the intercellular messengers) 148 • Function of several important interleukins 149 • The complement system 149 • Theories of immunotolerance 151 •Theoriesof autoimmunity 151 •AIDS 152 •Tissue transplantation and graft rejection 152 SEC-4—RESPIRATORY SYSTEM 155–228 Chapter 18 : Introduction 157 • Types of respiration 157 • Anatomical features 157 • Structure and innervation of tracheobronchial tree 159 • Some features of pulmonary circulation 159 • Effect of gravity on pulmonary circulation 160 Chapter 19 : Lung ventilation 162 • Lung volumes and capacities 162 • Dead space 166 • Alveolar ventilation 167 • Ventilation-perfusion ratio 168 • Fick’s law of diffusion 169 Chapter 20 : Mechanics of breathing 171 •Introduction 171 •Intrapleural pressure 171 • Pulmonary pressure 172 • Changes of the intrapleural and intrapulmonary pressures during respiration 172 • Muscles of respiration 173 • Sequence of events leading to inspiration and expiration 173 • Pressurevolume relationships 174 • Compliance 176 • Surfactant 178 • Interdependence 181 • Nature of airflow and airway resistance 181 • Closing volume 185 Chapter 21 : Oxygen transport 188 • In physical solution 189 • As oxyhemoglobin 189 Chapter 22 : CO2 transport 195 • In physical solution 195 • As carbamino compounds 195 • As bicarbonate 195 Chapter 23 : Neural regulation of respiration 198 • Dual control of respiration 198 • Automatic control 198 • Pontine centers 200 • Effects of transection at different levels 201 • Modern concept of respiration 202 Chapter 24 : Chemical control of respiration 204 • Short and long-term effect of hypoxia on respiration 205 • Effect of hypoxia on ventilation 206 • Effect of CO2 on respiration 206 • Effect of ph 207 • Breath holding 208 • Voluntary overbreathing 208 Chapter 25 : Miscellaneous topics (respiration) 209 • Hypoxic hypoxia 209 • Anemic hypoxia 211 • Stagnant hypoxia 212 • Histotoxic hypoxia 212 • CO poisoning 212 • Cyanosis 213 • Asphyxia 213 • High altitude sickness 214 • Compensatory changes of acclimatization 214 • Alveolar gas equation 215 xiv Principles of Physiology • Decompression sickness 216 • Air embolism 217 • Different types of breathing 218 • Effect of exercise on respiration 219 • Artificial respiration 221 Chapter 26 : Lung function tests 223 • Spirometry tests 223 • Anatomical and physiological dead space 223 • Functional residual capacity (FRC) 223 • Compliance 224 • PEFR (peak expiratory flow rate) 224 • Diffusing capacity 224 • Closing volume 224 • Blood gas and air analysis 224 • Nonrespiratory functions of lung 224 Chapter 27 : Respiratory diseases 226 • Bronchial asthma 226 • Emphysema 226 • Cystic fibrosis 227 • Pneumothorax 228 • Lung collapse or atelectasis 228 SEC-5—CARDIOVASCULAR SYSTEM 229–353 Chapter 28 : Functional anatomy 231 • Circulation through the heart 231 • Valves 232 • Pericardium 232 • Structure of cardiac muscle (in brief) 232 Chapter 29 : Characteristics of cardiac muscle 235 • Properties of cardiac muscle 235 Chapter 30 : Cardiac cycle, venous waves and venous return 255 • Atrial events 255 • Ventricular events 256 • Factors controlling venous return 259 • Pressure-volume loop 261 Chapter 31 : Cardiac output 263 • Introduction 263 • Measurement of cardiac output 263 •Physiological variationsincardiac output 265 • Factors controlling cardiac output 265 • Canine heart-lung preparation 271 Chapter 32 : Cardiovascular regulation 272 •Autoregulation 272 •Innervationoftheheart 273 •Cardiovascular centers 275 • Cardiovascular reflexes 276 • Experimental proofs of baroreceptor reflex and Valsalva maneuver 283 Chapter 33 : Blood pressure and its regulation 284 • Blood pressure 284 • Overview 285 • Factors determining blood pressure 285 • Physiological variations of BP 287 • Regulation of BP 287 • Effect of exercise on BP 291 • Hypertension 293 Chapter 34 : Heart rate 295 • Introduction 295 • Effect of sympathetic and parasympathetic stimulation on heart rate 295 • Physiological variations in heart rate 295 • Factors controlling heart rate 296 Contents xv Chapter 35 : Cerebral circulation 300 • Special features 300 • Regulation of cerebral circulation 302 Chapter 36 : Coronary circulation 303 • Introduction 303 • Factors regulating coronary blood flow 305 Chapter 37 : Other circulations 309 • Circulation through skeletal muscles 309 • Regulation of blood flow through skeletal muscle 309 • The microcirculation 310 •Transcapillaryexchange 311•Factorsinfluencingmicrocirculation 311 •The fetal circulation 312 •Changes after birth 313 • Splanchnic circulation 314 Chapter 38 : Electrocardiogram 316 • Introduction 316 • Volume conduction 316 • Spread of cardiac impulse 316 • Dipole, vector, etc. 316 • Convention of electrocardiography 318 • The leads 318 • Parts of a normal ecg 320 • Procedure of electrocardiography 321 • Arrhythmias 330 Chapter 39 : Effect of gravity and exercise on circulation 334 • Effect of gravity on circulation 334 • Postural hypotension 335 • Effect of acceleration and deceleration 335 • Effect of exercise on cvs 336 Chapter 40 : Hemodynamics 339 • Introduction 339 • Laminar flow and turbulent flow 339 • Relation between velocity of blood flow and diameter of blood vessel 340 • Bernoulli’s principle 340 • Relation between viscosity and resistance 342 • Critical closing pressure 342 • Law of laplace 343 Chapter 41 : Circulatory shock 346 • Hypovolemic shock 346 • Neurogenic shock 349 • Anaphylactic shock 349 • Septic shock 349 Chapter 42 : Cardiac failure 350 • Definition 350 • Causes of heart failure 350 • High output failure 350 • Compensatory changes in cardiac failure 350 • Major manifestations of decompensated heart failure 351 SEC-6—THE DIGESTIVE SYSTEM 355–418 Chapter 43 : Introduction 357 • The gastrointestinal tract and its functions 357 • General anatomical features of the gastrointestinal tract 357 •Innervation of xvi Principles of Physiology the gastrointestinal tract 358 • Blood supply of the gastrointestinal tract 359 Chapter 44 : Gastrointestinal hormones 360 • Gastrin 360 • Actions of gastrin 360 • Factors that stimulate secretion of gastrin 360 • Factorsinhibiting secretion of gastrin 360 •Zollinger-Ellisonsyndrome 360 •Cholecystokinin-pancreozymin 361 • Actions 361 • Factor stimulating secretion of CCK-PZ 361 • Secretin 361 • Some other gastrointestinal hormones 361 Chapter 45 : The salivary glands and saliva 363 • Anatomy of the salivary glands 363 • Nerve supply 363 • Histological features 364 • Constituents of saliva 364 • Effect of rate of flow of saliva on its composition 365 • Functions of saliva 365 • Stimulation of salivary secretion 365 • Control of salivary secretion 366 • Paralytic secretion 366 Chapter 46 : The stomach 367 • Functional anatomy 367 • Gastric glands 367 • Other related cells 368 • Composition of gastric secretion 368 • Constituents of gastric juice 369 • Mechanism of hcl secretion 370 • The chemical reactions 371 • Postprandial alkaline tide 371 • Regulation of hcl secretion 371 • Control of gastric secretion 373 • Experiments to study gastric secretion 375 • Dumping syndrome 376 • Functions of stomach 376 • Tests of gastric function 376 • Gastric mucosal barrier and peptic ulcer 377 • Peptic ulcer 378 • Other factors causing peptic ulcer 378 • Treatment of peptic ulcer 378 Chapter 47 : Exocrine pancreas 380 • Main constituents of pancreatic juice 380 • Mechanism of bicarbonate secretion 382 • Control of pancreatic secretion 382 • Steatorrhea 383 • Acute pancreatitis 383 Chapter 48 : The liver 384 • Anatomical features 384 • Composition of bile 385 • Constituents of liver bile 386 • Secretion of bile from liver 388 • Control of bile secretion 389 • Enterohepatic circulation 390 • Functions of bile 390 • Functions of liver 391 • Jaundice 391 • Van Den Bergh reaction 393 • Physiological jaundice 393 • Difference between hemolytic and obstructive jaundice 393 • Liver function tests 393 • Gallstones 395 Chapter 49 : Small intestine 396 • Brunner’s glands 396 • Crypts of Lieberkuhn 396 • Villi 396 • Core of the villus 396 • Other cells in small intestine 397 Contents xvii • Important constituents of succus entericus and their function 397 • Regulation of secretion 397 • Mechanism of water and electrolyte secretion in crypts of Lieberkuhn 397 Chapter 50 : Movements of the GI tract 399 • Basal electric rhythm 399 • Migrating motor complex 400 • Mastication 401 • Deglutition 401 • Achalasia cardia 402 •Gastroesophagealreflux 402 •Movements ofstomach403 •Factors influencing gastric emptying 404 • Vomiting 405 • Movements of the small intestine 406 • Segmentation movements 406 • Pendular movements 407 •Tonic movements 407 •Peristalsis 407 • Functions of peristalsis 408 • ‘Law of intestine’ and ‘polarity of the intestine’ 408 • Gastroileal reflex 408 • Paralytic ileus 408 • Malabsorption syndrome 409 • Steatorrhea 409 • Movementsin the large intestine 410 • Mass peristalsis 410 • Defecation 410 • Gastrocolic reflex 410 • Megacolon (Hirschsprung’s disease) 411 • Dietary fiber 411 • Blind loop syndrome 411 • Intestinal bacteria 412 Chapter 51 : Digestion 413 •Introduction 413 •Carbohydrates 413 • Digestion of carbohydrate 414 • Absorption of carbohydrate 414 • Lactose intolerance 415 • Digestion of proteins 416 • The digestive process 416 • Brush border proteases 416 • Absorption of amino acids 417 • Digestion of fat 417 • Absorption of fat 418 SEC-7—EXCRETORY SYSTEM 419–480 Chapter 52 : Nephron 421 • Functions of the kidney 421 • Structure of a nephron 421 • Bowman’s capsule 422 • Proximal convoluted tubule 423 • Henle’s loop 423 • The distal tubule 424 • The collecting ducts 424 • Cortical nephrons vs juxtamedullary nephrons 424 • Blood vessels of the kidney 425 • Features of renal circulation 426 • Juxtaglomerular apparatus 426 • Autoregulation of renal blood flow and gfr 427 Chapter 53 : Glomerular filtration 431 • Factors influencing glomerular filtration rate (gfr) 432 • Glomerular filtration rate (gfr) 433 • Filtration fraction 433 • Determination of gfr 433 • Criteria of a substance for measuring gfr 434 • Clearance 434 • Creatinine clearance 434 • Renal blood flow measurement by pah 435 xviii Principles of Physiology Chapter 54 : Tubular reabsorption 436 • Tubular reabsorption and Tm 436 • Different mechanisms of Na+-Reabsorption 436 • Function of the distal tubules and cortical collecting duct 441 • Sodium balance and regulation of ecf volume 442 • Glucose reabsorption 447 • Urea reabsorption 448 Chapter 55 : Concentration of urine 449-456 • The medullary osmotic gradient 449 • Countercurrent multiplication 449 • Role of urea 451 • Countercurrent exchangers 451 • Concentration of urine 453 • Obligatory, osmotic and facultative reabsorption of water 453 • Water intoxication 454 • Diuretics 455 • Osmotic diuresis 455 • Sequence of events in osmotic diuresis 456 Chapter 56 : Regulation of acid-base balance 457 • Overview of acidification of urine 464 Chapter 57 : Features of urine 467 • Normal and abnormal features of urine 467 • Microscopic constituents of urine 468 • Abnormal constituents of urine 468 • Renal function tests 470 Chapter 58 : Micturition 472 • Muscles of the bladder 472 • Nerves of the bladder 472 • Pressure rise in bladder 473 • Control of micturition 474 • Abnormal conditions of bladder 474 Chapter 59 : The skin 476 • Types of skin 476 • Histological features 476 • Appendages of the skin 477 • Color of the skin 479 • Function of skin 479 • Cutaneous circulation 479 • Triple response 480 SEC-8—METABOLISM 481–511 Chapter 60 : Enzymes and carbohydrate metabolism 483 • Enzymes 483 • Cofactors and coenzymes 484 • Factors regulating the rate of enzyme-catalyzed reactions 484 • Rate-limiting reaction 484 • Energy transfer in cells and high energy compounds 485 • Hydrogen-accepting coenzymes 485 • Oxidative phosphorylation 485 • Carbohydrate metabolism 486 • Interconversion of carbohydrate, fat and protein 487 • Glycolysis (Embden-Meyerhof pathway) 487 • Krebs cycle 489 • Glycogenesis and glycogenolysis 490 • Neoglucogenesis 491 • Role of liver in carbohydrate metabolism 491 • Kidney and blood glucose concentration 492 • Factors controlling blood glucose level 492 Contents xix Chapter 61 : Protein metabolism 493 • Structure of proteins 493 • Transamination and oxidative deamination 493 • Essential amino acids 494 Chapter 62 : Lipid metabolism 495 • Introduction 495 • ß-oxidation of fatty acids 495 • Ketone bodies 496 • Brown fat 497 Chapter 63 : Vitamins and nutrition 499 • Calorie requirement of the body 499 • Special groups 500 • The macronutrients 500 • Dietary considerations in some special groups 508 • Abnormalities of nutrition 509 • Acute starvation 509 • Adaptive changes in the body 510 • Obesity 510 • Protein-energy malnutrition 511 SEC-9—ENDOCRINE SYSTEM 513–588 Chapter 64 : Mechanism of hormone action 515 • Introduction 515 • Classification of hormones 515 • Agonist and antagonist 516 • Upregulation and downregulation of hormones 516 • G proteins and second messengers 516 • Mechanism of hormone action 518 • Feedback regulation 521 • Estimation of hormone level 521 • Radioimmunoassay 521 Chapter 65 : The pituitary gland 523 • Anatomical features 523 • Hypophyseal ‘tropic’ hormones 523 • Hypothalamic releasing hormones 524 • The hypophyseal portal system 524 • Hypothalamus-pituitary-target gland axis and feedback control 525 • Growth hormone 525 • Factors influencing gh secretion 526 • Mechanism of action 526 • Actions of gh 526 • Somatomedins 528 • Gigantism 529 •Acromegaly 529 • Dwarfism 530 • Pituitary insufficiency and Sheehan’s syndrome 530 • tsh 531 • acth (corticotropin) 531 • lh and fsh 532 • Prolactin 533 •Actions 533 •Applied 534 • Physiology of growth 534 • Hormones of posterior pituitary 535 • Mode of action of vasopressin 535 • Actions of vasopressin (adh) 535 • Control of vasopressin secretion 536 • Applied 536 • Oxytocin 537 Chapter 66 : Thyroid gland 539 • Structure 539 • Chemistry of thyroid hormones 539 • Synthesis of thyroid hormones 540 • Mode of action of thyroid hormones 543 • Action of thyroid hormones 543 • Regulation of thyroid secretion 545 • Features of hypothyroidism 545 • Causes of hyperthyroidism 546 • Treatment of hyperthyroidism 547 • Exophthalmos 547 • Wolff-Chaikoff effect 547 • Goiter 548 •Thyroid function tests 548 xx Principles of Physiology Chapter 67 : Adrenal cortex 550 • Chemical structure of the hormones 550 • Biosynthesis of adrenal steroid hormones 551 • Regulation of glucocorticoid secretion 552 • Mode of action of cortisol (glucocorticoid) 553 • Actions of cortisol 553 • Cushing’s syndrome 555 • Adrenogenital syndrome 556 • Aldosterone 557 • Conn’s syndrome 558 • Secondary hyperaldosteronism 559 • Addison’s disease 559 Chapter 68 : Adrenal medulla 561 • Actions of catecholamines 561 • Effects of dopamine 564 Chapter 69 : The calcium-related hormones 565 • Bone physiology 565 • Parathyroid hormone 566 • PTHrP 569 •Calcitriol or 1,25 (OH)2-vitamin D3 569 •Calcitonin 570 •Applied 571 • Tetany 572 • Rickets 573 • Osteomalacia 574 • Osteoporosis 574 Chapter 70 : Endocrine pancreas 575 • Insulin 575 • Diabetes mellltus 579 • Complications 581 • Glucagon 583 •Control of blood glucose 584 • Effects of hormones 585 • Effect of different organs 585 • Houssay animal 585 • Glucose tolerance test 586 • Hypoglycemia 586 SEC-10—REPRODUCTIVE SYSTEM 589–631 Chapter 71 : Sex differentiation 591 • X and Y chromosome 591 • Development of gonads and genitalia 591 • Abnormal sexual differentiation 592 • Hormonal defects 593 • Puberty 594 • Pubertal changes 594 • Pubertal abnormalities 595 Chapter 72 : Male reproductive system 597 • The male reproductive organs 597 • Spermatogenesis 597 • Structure of the seminiferous tubule and blood-testis barrier 597 • Stages of spermatogenesis 598 • Morphology of a sperm 599 • Semen 600 • Factors influencing spermatogenesis 600 • Testosterone 601 • Biosynthesis 602 • Mechanism of action 602 • Functions of testosterone 602 • Regulation of testicular activity 603 Chapter 73 : Female reproductive system 605 • The female reproductive organs 605 • The menstrual cycle 605 • Folliculogenesis in the ovary 606 • Ovarian cycle with brief hormonal basis 608 • Changes in the uterus 610 • Menstrual contents 611 •Changesin the cervix 611 •Changesin the vagina 612 • Indicators of ovulation 612 • Hormonal control of the menstrual cycle 612 • Hormones of the ovary 616 Contents xxi Chapter 74 : Pregnancy and lactation 621 • Fertilization 621 • Functions of placenta 622 • Hormones of the placenta 623 • Fetoplacental unit 624 • Fetal graft 625 • Pregnancy tests 626 • Infertility 626 • Contraception 626 • Mammary gland and lactation 629 • Effect of hormones 630 • Secretion and ejection of milk 630 • Effects of suckling 630 • Effect of lactation on menstruation 630 • Parturition 631 SEC-11—NERVOUS SYSTEM 633–776 Chapter 75 : Anatomical considerations 635 • Introduction 635 • The brain 635 • The cerebral hemispheres 635 • The diencephalon 636 • The brainstem 636 • The cerebellum 637 • Spinal cord 637 • Peripheral nervous system 637 • Cranial nerves 637 • The spinal nerves 639 • Cerebrospinal fluid 639 Chapter 76 : Neuron 642 • Structure of a neuron 642 • Properties of nerve fiber 643 • Axonal transport 644 • Neuroglia 644 • Myelination 646 • Classification of nerve fibers 647 • Nerve growth factor 648 • Nerve injury— degeneration and regeneration 648 • Changes in fifth degree injury 649 • Transneuronal degeneration 651 Chapter 77 : Synapse 652 • Definition 652 • Classification of a synapse 652 • Structure of a synapse 652 • Properties of synapse 654 Chapter 78 : Receptor 661 • Definition 661 • Classification 661 • Adaptation 663 • Mechanism of adaptation in pacinian corpuscle 663 • Properties of receptors 663 Chapter 79 : Reflex 666 • Definition 666 • Parts of a reflex arc 666 • Classification of reflex 666 • Stretch reflex 667 • Structure of a muscle spindle 667 • Innervation 668 • Action of muscle spindle 668 • Role of ?-efferents 669 • Inverse stretch reflex 669 • Clasp-knife rigidity 670 • Withdrawal reflex 670 • Other properties of reflexes 670 Chapter 80 : The sensory system 673-690 • Disposition of gray matter–rexed lamina 675 • The white matter 675 • Bell-Magendie’s law 675 • Dermatome 675 • Touch 676 • Pain 679 • Receptor 680 • Afferent nerve fiber 681 • Types of pain 681 • Pathways of pain 681 • Syringomyelia 683 • Referred pain 683 xxii Principles of Physiology •Dermatomalrule683•Roleof experience684•Theories explaining referred pain 684 • Different instances of ‘analgesia’ (loss of pain sensation) 685 • Pain-inhibiting mechanisms in the body 685 • Thalamic syndrome 687 • Surgical procedures for relief of pain 687 • Hyperalgesia and allodynia 688 • Itch 688 • Tickle 689 • Temperature 689 • The spinocerebellar tracts 689 Chapter 81 : Motor system 691 • Overview of motor system 691 • The cortical motor areas 691 •The pyramidal tract 693 • Nomenclature 693 • Origin 693 •Course 693 • Termination 694 • Corticonuclear fibers 694 • Functions of pyramidal tracts 694 •The extrapyramidal tracts 695 • Lower motor neuron 696 • Upper motor neuron 696 • Features of upper motor neuron lesion (umnl) 696 • Features of lower motor neuron lesion (lmnl) 696 • Complete transection of the cord 697 • Features of Brown-Sequard syndrome or hemisection of the spinal cord 698 • Tabes dorsalis 699 Chapter 82 : Cerebellum 700 • Anatomical divisions of the cerebellum 700 • Phylogenetic divisions of the cerebellum 700 • Functional divisions of the cerebellum 701 • Afferent connections of cerebellum 702 • The cerebellar nuclei and their efferent connections 702 • The cerebellar neurons and circuitry 704 • External connections of the cerebellum 707 • Function 707 • Signs of cerebellar lesion 708 Chapter 83 : Basal ganglia 710 • Anatomy 710 • Connections 710 • Functions 712 • Parkinson’s disease 713 • Huntington’s chorea 714 • Hemiballismus 714 Chapter 84 : Muscle tone 716 • Types of rigidity 717 • Decerebrate rigidity (of the sherringtonian type) 717 • Mechanism 718 • Decerebrate rigidity (ischemic) 718 • Decorticate rigidity 719 Chapter 85 : Maintenance of posture and equilibrium 720 • Local static reflex 720 • Segmental static reflexes 720 • Tonic reflexes 720 • Righting reflexes 721 • Hopping and placing reflexes 722 • The vestibular apparatus 722 • The utricle and the saccule 722 • Structure of the hair cell 723 • Semicircular canals 723 • Function of the utricle and the saccule 724 • Function of the semicircular canals 724 • Nystagmus 724 Contents xxiii Chapter 86 : Hypothalamus 727 • Anatomy 727 • Connections 727 • Functions 728 • Temperature regulationindetail733 •Characteristicsofnormalbodytemperature 733 • Mechanism of heat production 733 • Mechanisms of heat loss 734 • Mechanisms of temperature regulation 736 • Role of hypothalamus 736 • Fever 736 • Hypothermia 736 Chapter 87 : Autonomic nervous system 738 • Autonomic nervous system is divided into 738 • Applied 742 Chapter 88 : Thalamus 743 • General considerations 743 • Thalamic nuclei 743 • Connections and functions 744 • Reticular formation 745 • ras (reticular activating system) 745 • Descending reticular system 746 • Functions of reticular formation 746 Chapter 89 : Sleep and EEG 747 • Various rhythms in eeg 747 • Alpha-block 747 • Physiologic basis of eeg waves 748 • Patterns of eeg in sleep 748 • Genesis of sleep 749 • Sleep cycle 751 • Usefulness of eeg 751 • Epilepsy 751 • Evoked potential 752 Chapter 90 : Neurotransmitters 754 • Receptors of neurotransmitters 754 • Reuptake 755 • Brief description of some individual neurotransmitters 755 • Norepinephrine and epinephrine 756 • Dopamine 756 • Serotonin 757 • Histamine 757 • Glutamate and aspartate 757 • gaba and glycine 758 •Opioidpeptides 758 •Otherpolypeptides 759 •Cotransmitters 759 Chapter 91 : Cerebral cortex 761 • The cerebral hemispheres 761 • Structure of cerebral cortex 762 • Regional variations in cerebral cortex 763 • Cortical columns 763 • The lobes of the cerebral hemisphere 763 • Cerebral dominance 765 • Prosopagnosia 766 Chapter 92 : The limbic system 767 • Introduction 767 • Anatomy 767 • Connections (papez circuit) 768 • Kluver-Bucy animal 768 • Fear and rage 769 • Sham rage 769 • Reward and punishment systems of the brain and motivation 769 Chapter 93 : Higher functions 771 • Learning 771 • Conditioned reflex 771 • Memory 772 • Molecular mechanism of memory 772 • Alzheimer’s disease 774 • Language 774 xxiv Principles of Physiology SEC-12—SPECIAL SENSE 777–820 Chapter 94 : Structure of the eye 779 • The eye 779 • The cornea 779 • The sclera 780 • The middle coat 780 • The iris 780 • Ciliary body 781 • Choroid 781 • Aqueous humor 781 • Glaucoma 781 • The crystalline lens 782 • Vitreous humor 782 • The retina 782 • Function of rods and cones 785 Chapter 95 : Optics of the eye 786 • Accommodation 787 • Purkinje sanson images 787 • Presbyopia 788 • Other errors ofrefraction 788 • Field of vision 789 • Binocular vision 790 • Depth perception 790 Chapter 96 : Photochemistry 791 • Photochemical changes in the retina 791 • Resynthesis of photopigments and role of vitamin A 792 • Night blindness 793 • Center-surround antagonism of receptive fields 793 Chapter 97 : Visual pathway 795 • Anatomy of visual pathway 795 • Vision at cortical level 797 Chapter 98 : Miscellaneous topics 799 • Color vision 799 • Color blindness 799 • Purkinje shift 800 • Reflexes of the eye 800 • Movements of the eyeball 802 • Diplopia 802 • Light adaptation and dark adaptation 803 • Visual acuity 803 Chapter 99 : Hearing 805 • The external ear 805 • The middle ear 806 • The inner ear 806 • The organ of corti 807 • The central pathways of auditory nerve 808 • Sound transduction 808 • Determination of frequency and intensity of sound 811 • Sound localization 812 • Decibels, sound intensity and hearing range 812 • Masking 813 • Deafness 813 • Audiometry 814 Chapter 100 : Taste sensation 815 •Taste buds 816 • Papillae 816 • Gustatory papillae 816 • Mechanical papillae 816 • Taste pathways 816 • Molecular mechanism 817 Chapter 101 : Olfactory sensation 818 • Olfactory mucosa 818 • Olfactory pathways 819 • Adaptation of smell sensation 819 • Transduction 820 • Points to note 820 Appendices 821–832 • Appendix I 823 • Appendix II 826 Abbreviations 833 Index 837 Contents xxv