Guyton and Hall Textbook of Medical Physiology

Cover......Page 1
Note to Instructors......Page 2
Guyton and Hall Textbook of Medical Physiology......Page 3
Copyright......Page 4
Dedication......Page 5
Preface......Page 6
1 - Functional Organization of the Human Body and Control of the “Internal Environment”......Page 8
2 -
The Cell and Its Functions......Page 17
3 -
Genetic Control of Protein Synthesis, Cell Function, and Cell Reproduction......Page 34
4 - Transport of Substances Through Cell Membranes......Page 51
The Nernst Equation Describes the Relationship of Diffusion Potential to the Ion Concentration Difference Across a Membrane. The.........Page 63
The Goldman Equation Is Used to Calculate the Diffusion Potential When the Membrane Is Permeable to Several Different Ions. When.........Page 64
Resting Membrane Potential of Neurons......Page 65
Contribution of the Potassium Diffusion Potential. In Figure 5-­5A, we assume that the only movement of ions through the membran.........Page 66
Resting Stage. The resting stage is the resting membrane potential before the action potential begins. The membrane is said to b.........Page 67
Voltage-­Gated Potassium Channel and Its Activation......Page 68
Propagation of the Action Potential......Page 71
Plateau in Some Action Potentials......Page 72
Rhythmicity of Some Excitable Tissues—Repetitive Discharge......Page 73
Saltatory Conduction in Myelinated Fibers from Node to Node. Even though almost no ions can flow through the thick myelin sheath.........Page 74
Excitation—The Process of Eliciting the Action Potential......Page 75
In contrast to the factors that increase nerve excitability, membrane-­stabilizing factors can decrease excitability. For exampl.........Page 76
6 -
Contraction of Skeletal Muscle......Page 78
Neuromuscular Junction and Transmission of Impulses from Nerve Endings to Skeletal Muscle Fibers......Page 92
Acetylcholine Opens Ion Channels on Postsynaptic Membranes. Figure 7-2 also shows many small acetylcholine receptors and voltage.........Page 93
End Plate Potential and Excitation of the Skeletal Muscle Fiber. The sudden insurgence of sodium ions into the muscle fiber when.........Page 94
Safety Factor for Transmission at the Neuromuscular Junction—Fatigue of the Junction. Ordinarily, each impulse that arrives at t.........Page 95
Calcium Pump Removes Calcium Ions from the ­Myofibrillar Fluid After Contraction Occurs. Once the calcium ions have been release.........Page 96
Excitatory Pulse of Calcium Ions. The normal resting state concentration (<10−7 molar) of calcium ions in the cytosol that bathe.........Page 97
Chemical Basis for Smooth Muscle Contraction......Page 100
Comparison of Smooth Muscle Contraction and Skeletal Muscle Contraction......Page 101
Regulation of Contraction by Calcium Ions......Page 102
Role of the Smooth Muscle Sarcoplasmic Reticulum. Figure 8-4 shows a few slightly developed sarcoplasmic tubules that lie near t.........Page 103
Nervous and Hormonal Control of Smooth Muscle Contraction......Page 104
Membrane Potentials in Smooth Muscle. The quantitative voltage of the membrane potential of smooth muscle depends on the momenta.........Page 105
Slow Wave Potentials in Unitary Smooth Muscle Can Lead to Spontaneous Generation of Action Potentials. Some smooth muscle is sel.........Page 106
Mechanisms of Smooth Muscle Excitation or Inhibition by Hormones or Local Tissue Factors. Some hormone receptors in the smooth m.........Page 107
Cardiac Muscle Anatomy......Page 109
Cardiac Cycle......Page 113
The Atria Function as Primer Pumps for the Ventricles......Page 114
End-­Diastolic Volume, End-­Systolic Volume, and Stroke Volume Output. During diastole, normal filling of the ventricles increas.........Page 115
Aortic Pressure Curve......Page 116
Volume-­Pressure Diagram During the Cardiac Cycle; Cardiac Work Output. The red lines in Figure 9-­10 form a loop called the vol.........Page 117
Concepts of Preload and Afterload. In assessing the contractile properties of muscle, it is important to specify the degree of t.........Page 118
Ventricular Function Curves......Page 119
Control of the Heart by the Sympathetic and Parasympathetic Nerves......Page 120
Mechanism of Sinus Nodal Rhythmicity. Figure 10-­2 shows action potentials recorded from inside a sinus nodal fiber for three he.........Page 123
Leakiness of Sinus Nodal Fibers to Sodium and Calcium Causes Self-­Excitation. Because of the high sodium ion concentration in t.........Page 124
Cause of the Slow Conduction. The slow conduction in the transitional, nodal, and penetrating A-­V bundle fibers is caused mainl.........Page 125
Distribution of the Purkinje Fibers in the Ventricles—Left and Right Bundle Branches. After penetrating the fibrous tissue betwe.........Page 126
Abnormal Pacemakers—Ectopic Pacemaker. Occasio­nally, some other part of the heart develops a rhythmical discharge rate that is .........Page 127
Mechanism of the Sympathetic Effect. Stimulation of the sympathetic nerves releases norepinephrine at the sympathetic nerve endi.........Page 128
Relation of the Monophasic Action Potential of Ventricular Muscle to the QRS and T Waves in the Standard Electrocardiogram. The .........Page 130
Recording Electrical Potentials from a Partially Depolarized Mass of Syncytial Cardiac Muscle......Page 132
Three Standard Bipolar Limb Leads......Page 133
Normal Electrocardiograms Recorded from the Three Standard Bipolar Limb Leads. Figure 11-­7 shows recordings of the ECGs in lead.........Page 134
Augmented Limb Leads......Page 135
12 - Electrocardiographic Interpretation of Cardiac Muscle and Coronary Blood Flow Abnormalities: Vectorial Analysis......Page 137
Sinus Arrhythmia......Page 151
First-­Degree Block—Prolonged P-­R Interval. The usual lapse of time between the beginning of the P wave and the beginning of th.........Page 152
Stokes-­Adams Syndrome—Ventricular Escape. In some patients with A-­V block, the total block comes and goes; that is, impulses a.........Page 153
Pulse Deficit. When the heart contracts ahead of schedule, the ventricles will not have filled with blood normally, and the stro.........Page 154
Disorders of Cardiac Repolarization—the Long QT Syndromes. Recall that the Q wave corresponds to ventricular depolarization, whe.........Page 155
Paroxysmal Atrial Tachycardia......Page 156
Ventricular Fibrillation......Page 157
Ventricular Defibrillation......Page 159
Atrial Fibrillation......Page 160
Cardiac Arrest......Page 161
Functional Parts of the Circulation. Before discussing the details of circulatory function, it is important to understand the ro.........Page 163
Pressures in the Various Portions of the Circulation. Because the heart pumps blood continually into the aorta, the mean pressur.........Page 164
Interrelationships of Pressure, Flow, and Resistance......Page 165
Electromagnetic Flowmeter. An electromagnetic flowmeter, the principles of which are illustrated in Figure 14-4, can be used to .........Page 166
Turbulent Flow of Blood Under Some Conditions. When the rate of blood flow becomes too great, when it passes by an obstruction i.........Page 167
Blood Pressure......Page 168
Poiseuille’s Law. The cause of this great increase in conductance when the diameter increases can be explained by referring to F.........Page 169
Effect of Blood Hematocrit and Blood Viscosity on Vascular Resistance and Blood Flow......Page 170
Autoregulation Attenuates the Effect of Arterial Pressure on Tissue Blood Flow. From the discussion thus far, one might expect a.........Page 171
Vascular Wall Tension. Tension on the blood vessel wall develops in response to transmural pressure gradients and causes vascula.........Page 172
Vascular Shear Stress. As blood flows it creates a frictional force, or drag, on the endothelial cells lining the blood vessels .........Page 173
The Veins Are Much More Distensible Than the Arteries. The walls of the arteries are thicker and far stronger than those of the .........Page 174
Arterial Pressure Pulsations......Page 175
Abnormal Pressure Pulse Contours......Page 176
Auscultatory Method. Figure 15-7 shows the auscultatory method for determining systolic and diastolic arterial pressures. A stet.........Page 177
Mean Arterial Pressure. The mean arterial pressure is the average of the arterial pressures measured millisecond by millisecond .........Page 178
Effect of High Right Atrial Pressure on Peripheral Venous Pressure. When the right atrial pressure rises above its normal value .........Page 179
Effect of Gravitational Pressure on Venous Pressure......Page 180
Venous Valve Incompetence Causes Varicose Veins. The valves of the venous system may become incompetent or even be destroyed whe.........Page 181
Specific Blood Reservoirs......Page 182
Reticuloendothelial Cells of the Spleen. The pulp of the spleen contains many large phagocytic reticuloendothelial cells, and th.........Page 183
Pores in the Capillary Membrane. Figure 16-­2 shows two small passageways connecting the interior of the capillary with the exte.........Page 184
Regulation of Vasomotion. The most important factor affecting the degree of opening and closing of the metarterioles and precapi.........Page 185
Effect of Molecular Size on Passage Through the Pores. The width of the capillary intercellular cleft pores, 6 to 7 nanometers, .........Page 186
Gel in the Interstitium. The fluid in the interstitium is derived by filtration and diffusion from the capillaries. It contains .........Page 187
Capillary Hydrostatic Pressure......Page 188
Plasma Proteins Cause Colloid Osmotic Pressure. As discussed in Chapter 4, only the molecules or ions that fail to pass through .........Page 189
Analysis of the Forces Causing Filtration at the ­Arterial End of the Capillary. The approximate average forces operative at the.........Page 190
Capillary Filtration Coefficient......Page 191
Lymph Channels of the Body......Page 192
Effect of Interstitial Fluid Pressure on Lymph Flow. Figure 16-­8 shows the effect of different levels of interstitial fluid hyd.........Page 193
Lymphatic Capillary Pump. The terminal lymphatic capillary is also capable of pumping lymph, in addition to the pumping by the l.........Page 194
Significance of Negative Interstitial Fluid Pressure for Holding Body Tissues Together......Page 195
Mechanisms of Blood Flow Control......Page 196
Vasodilator Theory for Acute Local Blood Flow Regulation—Possible Special Role of Adenosine. According to the vasodilator theory.........Page 197
Possible Role of Other Nutrients Besides Oxygen in Control of Local Blood Flow. Under special conditions, it has been shown that.........Page 198
Autoregulation of Blood Flow During Changes in Arterial Pressure—Metabolic and Myogenic Mechanisms......Page 199
Special Mechanisms for Acute Blood Flow Control in Specific Tissues......Page 200
Endothelin Is a Powerful Vasoconstrictor Released From Damaged Endothelium. Endothelial cells also release vasoconstrictor subst.........Page 201
Role of Oxygen in Long-­Term Regulation. Oxygen is important not only for acute control of local blood flow but also for long-­t.........Page 202
Blood Flow Regulation by Development of Collateral Circulation......Page 203
Vascular Remodeling in Response to Chronic Changes in Blood Flow or Blood Pressure......Page 204
Bradykinin. Several substances called kinins cause powerful vasodilation when formed in the blood and tissue fluids of some orga.........Page 205
Most Vasodilators or Vasoconstrictors Have Little ­Effect on Long-­Term Blood Flow Unless They Alter the Metabolic Rate of the T.........Page 206
Parasympathetic Stimulation Decreases Heart Rate and Contractility. Although the parasympathetic nervous system is exceedingly i.........Page 208
Vasomotor Center in the Brain and Its Control of the Vasoconstrictor System. Located bilaterally mainly in the reticular substan.........Page 209
Norepinephrine Is the Sympathetic Vasoconstrictor Neurotransmitter. The substance secreted at the ­endings of the vasoconstricto.........Page 210
Nervous Control of Arterial Pressure Is Rapid. An especially important characteristic of nervous control of arterial pressure is.........Page 211
Physiologic Anatomy of the Baroreceptors and Their Innervation. Baroreceptors are spray-­type nerve endings that lie in the wall.........Page 212
Baroreceptors Attenuate Blood Pressure Changes During Changes in Body Posture. The ability of the baroreceptors to maintain rela.........Page 213
Are the Baroreceptors Important in Long-­Term ­Regulation of Arterial Pressure Although the arterial baroreceptors provide power.........Page 214
Increased Atrial Pressure Raises Heart Rate—Bainbridge Reflex. Increases in atrial pressure sometimes increase the heart rate as.........Page 215
Skeletal Muscle Contraction Increases Cardiac ­Output and Arterial Pressure During Exercise. When the skeletal muscles contract .........Page 217
Oscillation of CNS Ischemic Response. The record in Figure 18-­11A resulted from oscillation of the CNS ischemic pressure contro.........Page 218
Experiment Demonstrating the Renal–Body Fluid System for Arterial Pressure Control. Figure 19-­2 shows the results of an experim.........Page 220
Two Key Determinants of Long-­Term Arterial Pressure. In Figure 19-­1, one can also see that two basic long-­term factors determ.........Page 221
Chronic Renal Output Curve Much Steeper Than the Acute Curve. An important characteristic of pressure natriuresis (and pressure .........Page 222
Increased Fluid Volume Can Elevate Arterial Pressure by Increasing Cardiac Output or Total Peripheral Resistance......Page 223
Importance of Salt (NaCl) in the Renal–Body Fluid Schema for Arterial Pressure Regulation......Page 224
Experimental Volume-­Loading Hypertension Caused by Reduced Kidney Mass and Increased Salt Intake. Figure 19-­7 shows a typical .........Page 225
Volume-­Loading Hypertension in Patients Who Have No Kidneys but Are Being Maintained With an Artificial Kidney......Page 226
Role of the Renin-­Angiotensin System in Arterial Pressure Control......Page 227
Angiotensin II Increases Kidney Salt and Water ­Retention by Stimulating Aldosterone. Angiotensin II is also one of the most pow.........Page 228
Role of the Renin-­Angiotensin System in Maintaining a Normal Arterial Pressure Despite Large Variations in Salt Intake......Page 229
One-­Kidney Goldblatt Hypertension. When one kidney is removed, and a constrictor is placed on the renal artery of the remaining.........Page 230
Hypertension Caused by Diseased Kidneys That Secrete Renin Chronically. Often, patchy areas of one or both kidneys are diseased .........Page 231
Primary (Essential) Hypertension......Page 232
Graphic Analysis of Arterial Pressure Control in Essential Hypertension. Figure 19-­15 is a graphic analysis of essential hypert.........Page 233
Arterial Pressure Control Mechanisms That Act Within Seconds or Minutes. The rapidly acting pressure control mechanisms are almo.........Page 234
Long-­Term Mechanisms for Arterial Pressure Regulation. The goal of this chapter has been to explain the role of the kidneys in .........Page 235
Control of Cardiac Output by Venous Return—Frank-­Starling Mechanism of the Heart......Page 236
Cardiac Output Is the Sum of All Tissue Blood Flows—Tissue Metabolism Regulates Most Local Blood Flow......Page 237
Factors That Cause a Hypoeffective Heart......Page 238
Effect of Nervous System to Increase Arterial Pressure During Exercise. During exercise, intense increases in metabolism in acti.........Page 239
Combinations of Different Patterns of Cardiac Output Curves. Figure 20-­9 shows that the final cardiac output curve can change a.........Page 241
Plateau in Venous Return Curve at Negative Atrial Pressures Caused by Collapse of the Large Veins. When the right atrial pressur.........Page 242
Effect on Venous Return Curve of Changes in Mean Systemic Filling Pressure. Figure 20-­12 shows the effects on the venous return.........Page 243
Combinations of Venous Return Curve Patterns. Figure 20-­14 shows the effects on the venous return curve caused by simultaneous .........Page 244
Effect of Sympathetic Stimulation on Cardiac Output. Sympathetic stimulation affects the heart and systemic circulation: (1) it .........Page 245
Effect of Opening a Large Arteriovenous Fistula. Figure 20-­17 shows various stages of circulatory changes that occur after open.........Page 246
Indicator Dilution Method......Page 247
Bibliography......Page 248
Decreased Oxygen in Muscle Greatly Enhances Flow. The large increase in muscle blood flow that occurs during skeletal muscle act.........Page 250
Sympathetic Stimulation May Increase Arterial Pressure During Exercise......Page 251
Graphic Analysis of Changes in Cardiac Output ­During Heavy Exercise. Figure 21-­2 shows a graphic analysis of the large increas.........Page 252
Cardiac Muscle Compression Causes Phasic Changes in Coronary Blood Flow During Systole and Diastole. Figure 21-­4 shows the chan.........Page 253
Nervous Control of Coronary Blood Flow......Page 254
Ischemic Heart Disease......Page 255
Myocardial Infarction......Page 256
Fibrillation of the Ventricles After Myocardial Infarction. In many people who die of coronary occlusion, death occurs because o.........Page 257
Replacement of Dead Muscle by Scar Tissue. In the lower part of Figure 21-­8, the various stages of recovery after a large myoca.........Page 258
Drug Treatment. Several vasodilator drugs, when administered during an acute anginal attack, can often provide immediate relief .........Page 259
Aortic-­Coronary Bypass Surgery. In many patients with coronary ischemia, the constricted areas of the coronary arteries are loc.........Page 260
22 - Cardiac Failure......Page 261
23 - Heart Valves and Heart Sounds; Valvular and Congenital Heart Defects......Page 272
Circulatory Shock Caused by Decreased Cardiac Output......Page 281
Greater Effect of Sympathetic Nervous Reflexes in Maintaining Arterial Pressure Than in Maintaining Cardiac Output. Referring ag.........Page 282
Nonprogressive Shock—Compensated Shock......Page 283
Cardiac Depression. When the arterial pressure falls low enough, coronary blood flow decreases below that required for adequate .........Page 284
Generalized Cellular Deterioration. As shock becomes severe, many signs of generalized cellular deterioration occur throughout t.........Page 285
Irreversible Shock......Page 286
Neurogenic Shock—Increased Vascular Capacity......Page 287
Septic Shock......Page 288
Circulatory Arrest......Page 289
Water Loss by the Kidneys. The remaining water loss from the body occurs in the urine excreted by the kidneys. Multiple mechanis.........Page 291
Intracellular Fluid Compartment......Page 292
Constituents of Extracellular and Intracellular Fluids......Page 293
Measurement of Body Fluid Compartment Volumes—Indicator-­Dilution Principle......Page 294
Measurement of Blood Volume. If one measures the hematocrit (the fraction of the total blood volume composed of cells) and plasm.........Page 295
Osmolarity of Body Fluids. Referring back to Table 25-­2, note the approximate osmolarity of the various osmotically active subs.........Page 296
Osmotic Equilibrium Between Intracellular and ­Extracellular Fluids Is Rapidly Attained. Transfer of fluid across the cell membr.........Page 297
Effect of Adding Saline Solution to the Extracellular Fluid......Page 298
Glucose and Other Solutions Administered For Nutritive Purposes......Page 299
Hyponatremia Causes Cell Edema......Page 300
Hypernatremia Causes Cell Shrinkage......Page 301
Summary of Causes of Extracellular Edema......Page 302
Edema Caused by Decreased Plasma Proteins. Failure to produce normal amounts of proteins or leakage of proteins from the plasma .........Page 303
Importance of Interstitial Gel in Preventing Fluid ­Accumulation in the Interstitium. Note in Figure 25-­8 that in normal tissue.........Page 304
Fluid Is Exchanged Between Capillaries and Potential Spaces. The surface membrane of a potential space usually does not offer si.........Page 305
Edema Fluid in the Potential Spaces Is Called ­Effusion. When edema occurs in the subcutaneous tissues adjacent to the potential.........Page 306
Regulation of Water and Electrolyte Balances. For main­tenance of homeostasis, excretion of water and electrolytes must match in.........Page 307
General Organization of the Kidneys and Urinary Tract......Page 308
Renal Blood Supply......Page 309
Micturition......Page 310
Innervation of the Bladder. The principal nerve supply of the bladder is via the pelvic nerves, which connect with the spinal co.........Page 312
Micturition Reflex......Page 313
Urine Formation Results from Glomerular Filtration, Tubular Reabsorption, and Tubular Secretion......Page 315
Glomerular Capillary Membrane......Page 317
Negatively Charged Large Molecules Are Filtered Less Easily Than Positively Charged Molecules of Equal Molecular Size. The molec.........Page 318
Determinants of the Glomerular Filtration Rate......Page 319
Determinants of Renal Blood Flow......Page 322
Physiological Control of Glomerular Filtration and Renal Blood Flow......Page 323
Autoregulation of Glomerular Filtration Rate and Renal Blood Flow......Page 324
Importance of Glomerular Filtration Rate Autoregulation in Preventing Extreme Changes in Renal Excretion......Page 325
Tubular Reabsorption Includes Passive and Active Mechanisms......Page 329
Active Transport......Page 330
Proximal Tubular Reabsorption......Page 335
Distal Tubules......Page 337
Medullary Collecting Ducts......Page 340
Regulation of Tubular Reabsorption......Page 341
Use of Clearance Methods to Quantify Kidney Function......Page 346
Kidneys Excrete Excess Water by Forming Dilute Urine......Page 351
Tubular Fluid in Distal and Collecting Tubules Is Further Diluted in Absence of ADH. As the dilute fluid in the early distal tub.........Page 352
Kidneys Conserve Water by Excreting Concentrated Urine......Page 353
Loop of Henle Characteristics That Cause Solutes to be Trapped in the Renal Medulla......Page 354
Steps Involved in Causing Hyperosmotic Renal Medullary Interstitium. Keeping in mind these characteristics of the loop of Henle,.........Page 355
Recirculation of Urea from Collecting Duct to Loop of Henle Contributes to Hyperosmotic Renal Medulla. A healthy person usually .........Page 356
Proximal Tubule. About 65% of most filtered electrolytes is reabsorbed in the proximal tubule. However, the proximal tubular mem.........Page 358
Inner Medullary Collecting Ducts. The concentration of fluid in the inner medullary collecting ducts also depends on the followi.........Page 359
Osmoreceptor-­ADH Feedback System......Page 361
Importance of Thirst in Controlling Extracellular Fluid Osmolarity and Sodium Concentration......Page 363
Stimuli for Thirst......Page 364
Regulation of Extracellular Fluid Potassium Concentration and Potassium Excretion......Page 368
Increased Extracellular Fluid Osmolarity Causes Redistribution of Potassium From Cells to Extracellular Fluid. Increased extrace.........Page 369
Variable Potassium Secretion in Distal and Collecting Tubules Mediates Most Daily Changes in Potassium Excretion. The most impor.........Page 370
Increased Extracellular Fluid Potassium Concentration Stimulates Potassium Secretion. The rate of potassium secretion in the lat.........Page 371
Blockade of Aldosterone Feedback System Greatly Impairs Potassium Regulation. In the absence of aldosterone secretion, as occurs.........Page 372
Increased Distal Tubular Flow Rate Stimulates Potassium Secretion. A rise in distal tubular flow rate, as occurs with volume exp.........Page 373
Acute Acidosis Decreases Potassium Secretion. Acute increases in extracellular fluid hydrogen ion concentration (acidosis) reduc.........Page 374
Regulation of Renal Calcium Excretion and Extracellular Calcium Ion Concentration......Page 375
Regulation of Renal Phosphate Excretion......Page 376
Integration of Renal Mechanisms for Control of Extracellular Fluid......Page 377
Pressure Natriuresis and Diuresis: Key Components of A Renal–Body Fluid Feedback for Regulating Body Fluid Volumes and Arterial .........Page 379
Nervous and Hormonal Factors Increase Effectiveness of Renal–Body Fluid Feedback Control......Page 381
Integrated Responses to Changes in Sodium Intake......Page 384
Conditions That Cause Large Increases in Extracellular Fluid Volume With Normal or Reduced Blood Volume......Page 385
Strong and Weak Acids and Bases. A strong acid, such as HCl, rapidly dissociates and releases especially large amounts of H+ in .........Page 387
Buffering of H+ in the Body Fluids......Page 388
Bicarbonate Buffer System......Page 389
Proteins are Important Intracellular Buffers......Page 391
Respiratory Regulation of Acid–­Base Balance......Page 392
Renal Control of Acid–Base Balance......Page 393
Secretion of H+ and Reabsorption of HCO3− by the Renal Tubules......Page 394
Combination of Excess H+ with Phosphate and Ammonia Buffers In the Tubule Generates “New” HCO3−......Page 396
Regulation of Renal Tubular H+ Secretion......Page 398
Renal Correction of Acidosis—Increased Excretion of H+ and Addition of HCO3− to the Extracellular Fluid......Page 399
Renal Correction of Alkalosis—Decreased Tubular Secretion of H+ and Increased Excretion of HCO3−......Page 400
32 - Diuretics and Kidney Diseases......Page 405
Areas of the Body That Produce Red Blood Cells. In the early weeks of embryonic life, primitive nucleated RBCs are produced in t.........Page 420
Erythropoietin Regulates Red Blood Cell Production......Page 422
Erythropoietin Stimulates Production of Proerythroblasts From Hematopoietic Stem Cells. When an animal or person is placed in an.........Page 423
Hemoglobin Formation......Page 424
Transport and Storage of Iron. Transport, storage, and metabolism of iron in the body are diagrammed in Figure 33-­7 and can be .........Page 425
Destruction of Hemoglobin by Macrophages. When RBCs burst and release their hemoglobin, the hemoglobin is phagocytized almost im.........Page 426
Hemolytic Anemia. Different abnormalities of the RBCs, many of which are acquired through hereditary, make the cells fragile, so.........Page 427
Secondary Polycythemia. Whenever the tissues become hypoxic because of too little oxygen in the breathed air, such as at high al.........Page 428
Genesis of White Blood Cells......Page 429
Neutrophils and Macrophages Defend Against Infections......Page 430
Phagocytosis by Neutrophils. The neutrophils entering the tissues are already mature cells that can immediately begin phagocytos.........Page 431
Monocyte-­Macrophage Cell System (Reticuloendothelial System)......Page 432
Macrophages of Spleen and Bone Marrow. If an invading organism succeeds in entering the general circulation, there are other lin.........Page 433
Neutrophil Invasion of the Inflamed Area Is a Second Line of Defense. Within the first hour or so after inflammation begins, lar.........Page 434
Second Macrophage Invasion Into the Inflamed Tissue Is a Third Line of Defense. Along with the invasion of neutrophils, monocyte.........Page 435
Eosinophils......Page 436
Leukemias......Page 437
Acquired (Adaptive) Immunity......Page 439
T and B Lymphocytes Promote Cell-­Mediated and ­Humoral Immunity. Although most lymphocytes in normal lymphoid tissue look alike.........Page 440
Millions of Specific Types of Lymphocytes Are Stored in Lymphoid Tissue. Millions of different types of preformed B lymphocytes .........Page 441
Antibody Formation by Plasma Cells. Before exposure to a specific antigen, the clones of B lymphocytes remain dormant in the lym.........Page 442
Nature of Antibodies......Page 443
Direct Action of Antibodies on Invading Agents. Figure 35-­5 shows antibodies (designated by the red Y-­shaped bars) reacting wi.........Page 444
Classical Pathway. The classical pathway is initiated by an antigen-­antibody reaction. That is, when an antibody binds with an .........Page 445
T-­Helper Cells Are the Most NumerousT Cells......Page 446
Cytotoxic T Cells Are Killer Cells......Page 447
Failure of the Tolerance Mechanism Causes Autoimmune Diseases. Sometimes, people lose immune tolerance of their own tissues. Thi.........Page 448
Allergy and Hypersensitivity......Page 449
Asthma. Asthma often occurs in the hypersensitive allergic person. In these individuals, the allergen-­reagin reaction occurs in.........Page 450
A and B Antigens—Agglutinogens......Page 451
Blood Typing......Page 452
Rh Immune Response......Page 453
Transfusion Reactions Resulting From Mismatched Blood Types......Page 454
Transplantation of Tissues and Organs......Page 455
Mechanism of Platelet Plug Formation......Page 457
GENERAL MECHANISM......Page 459
CONVERSION OF FIBRINOGEN TO FIBRIN—FORMATION OF THE CLOT......Page 460
Extrinsic Pathway for Initiating Clotting......Page 461
Intrinsic Pathway for Initiating Clotting......Page 462
Interaction Between Extrinsic and Intrinsic Pathways—Summary of Blood-­Clotting Initiation......Page 463
CONDITIONS THAT CAUSE EXCESSIVE BLEEDING IN HUMANS......Page 464
THROMBOCYTOPENIA......Page 465
COUMARINS AS ANTICOAGULANTS......Page 466
CLOTTING TIME......Page 467
38 - Pulmonary Ventilation......Page 469
39 - Pulmonary Circulation, Pulmonary Edema, and Pleural Fluid......Page 480
40 - Principles of Gas Exchange; Diffusion of Oxygen and Carbon Dioxide Through the Respiratory Membrane......Page 488
Alveolar Air Is Slowly Renewed by Atmospheric Air......Page 490
CO2 Concentration and Partial Pressure in Alveoli......Page 491
Factors Affecting Rate of Gas Diffusion Through the Respiratory Membrane......Page 493
Diffusing Capacity for Carbon Dioxide. The diffusing capacity for CO2 has never been measured because CO2 diffuses through the r.........Page 494
Uptake of Oxygen by the Pulmonary Blood During Exercise. During strenuous exercise, a person’s body may require as much as 20 ti.........Page 498
Increasing Blood Flow Raises Interstitial Fluid Po2. If the blood flow through a particular tissue is increased, greater quantit.........Page 499
Transport of Oxygen Is Markedly Increased During Strenuous Exercise. During heavy exercise, the muscle cells use O2 at a rapid r.........Page 501
Factors That Shift the Oxygen-­Hemoglobin Dissociation Curve—Their Importance for Oxygen Transport......Page 502
Effect of Intracellular Po2 on Oxygen Usage Rate. Only a minute level of O2 pressure is required in the cells for normal intrace.........Page 503
Effect of Blood Flow on Metabolic Use of Oxygen. The total amount of O2 available each minute for use in any given tissue is det.........Page 504
Transport of CO2 in a Dissolved State......Page 505
When Oxygen Binds With Hemoglobin, CO2 Is Released (the Haldane Effect) to Increase CO2 Transport......Page 506
Respiratory Exchange Ratio......Page 507
Rhythmical Inspiratory Discharges From the Dorsal Respiratory Group. The basic rhythm of respiration is generated mainly in the .........Page 508
Attenuated Stimulatory Effect of CO2 After the First 1 to 2 Days. Excitation of the respiratory center by CO2 is great the first.........Page 510
Peripheral Chemoreceptor System—Role of Oxygen in Respiratory Control......Page 511
Effect of Low Arterial Po2 to Stimulate Alveolar Ventilation When Arterial CO2 and H+ Concentrations Remain Normal......Page 512
Regulation of Respiration During Exercise......Page 513
Interrelationship Between Chemical and Nervous Factors in Controlling Respiration During Exercise. When a person exercises, dire.........Page 514
Determination of Blood Po2. The concentration of O2 in a fluid can be measured by a technique called polarography. Electric curr.........Page 518
Abnormalities of the Maximum Expiratory Flow-­Volume Curve. Figure 43-­2 shows the normal maximum expiratory flow-­volume curve,.........Page 519
Chronic Pulmonary Emphysema......Page 520
Lack of “Surfactant” as a Cause of Lung Collapse. The secretion and function of surfactant in the alveoli were discussed in Chap.........Page 522
Hypoxia and Oxygen Therapy......Page 523
Cyanosis......Page 524
Tank Respirator (the “Iron Lung”). Figure 43-­9B shows the tank respirator with a patient’s body inside the tank and the head pr.........Page 525
Effect of the Resuscitator and the Tank Respirator on Venous Return. When air is forced into the lungs under positive pressure b.........Page 526
Saturation of Hemoglobin With Oxygen at Different Altitudes. Figure 44-­1 shows arterial blood O2 saturation at different altitu.........Page 527
Increased Pulmonary Ventilation—Role of Arterial Chemoreceptors. Immediate exposure to low Po2 stimulates the arterial chemorece.........Page 528
Cellular Acclimatization. In animals native to altitudes of 13,000 to 17,000 feet, cell mitochondria and cellular oxidative enzy.........Page 529
Chronic Mountain Sickness......Page 531
Effect of Very High Po2 on Blood Oxygen Transport. When the Po2 in the blood rises above 100 mm Hg, the amount of O2 dissolved i.........Page 535
Excessive Intracellular Oxidation as a Cause of Nervous System Oxygen Toxicity—Oxidizing Free Radicals. Molecular O2 has little .........Page 536
Decompression of the Diver After Excess Exposure to High Pressure......Page 537
Tank Decompression and Treatment of Decompression Sickness. Another procedure widely used for decompression of professional dive.........Page 538
Self-­Contained Underwater Breathing Apparatus (Scuba) Diving......Page 539
Central Nervous System Neuron: The Basic Functional Unit......Page 541
Lower Brain or Subcortical Level......Page 543
Central Nervous System Synapses......Page 544
“One-­Way” Conduction at Chemical Synapses. Chemical synapses have one exceedingly important characteristic that makes them high.........Page 545
Ion Channels. The ion channels in the postsynaptic neuronal membrane are usually of two types: (1) cation channels, which usuall.........Page 546
“Second Messenger” System in the Postsynaptic Neuron. Many functions of the nervous system—for example, the process of memory—re.........Page 547
Inhibition......Page 548
Recycling of Small-­Molecule Types of Vesicles. Vesicles that store and release small-­molecule transmitters are continually rec.........Page 549
Neuropeptide and Small-­Molecule Transmitters May Coexist in the Same Neurons. Slowly acting neuropeptide transmitters and rapid.........Page 550
Concentration Differences of Ions Across the Neuronal Somal Membrane. Figure 46-­9 also shows the concentration differences acro.........Page 551
Effect of Synaptic Excitation on the Postsynaptic Membrane—Excitatory Postsynaptic Potential. Figure 46-­10A shows the resting n.........Page 552
Effect of Inhibitory Synapses on the Postsynaptic Membrane—Inhibitory Postsynaptic Potential. The inhibitory synapses mainly ope.........Page 553
“Temporal Summation” Caused by Successive Discharges of a Presynaptic Terminal......Page 554
Summation of Excitation and Inhibition in Dendrites. The uppermost dendrite of Figure 46-­12 is shown to be stimulated by both e.........Page 555
Effect of Drugs on Synaptic Transmission. Many drugs are known to increase the excitability of neurons, and others are known to .........Page 556
Synaptic Delay. During transmission of a neuronal signal from a presynaptic neuron to a postsynaptic neuron, a certain amount of.........Page 557
Local Electrical Currents at Nerve Endings—Receptor Potentials......Page 558
Relation of the Receptor Potential to Action Potentials. When the receptor potential rises above the threshold for eliciting act.........Page 559
Adaptation of Receptors......Page 560
Rapidly Adapting Receptors Detect Change in Stimulus Strength—the “Rate Receptors,” “Movement Receptors,” or “Phasic Receptors.”.........Page 561
Predictive Function of the Rate Receptors. If the rate at which some change in the body’s status is taking place is known, the s.........Page 562
Transmission and Processing of Signals in Neuronal Pools......Page 563
Divergence of Signals Passing Through Neuronal Pools......Page 564
Neuronal Circuit With Both Excitatory and Inhibitory Output Signals......Page 565
Signal Prolongation Characteristics of a Reverberatory Circuit. Figure 47-­15 shows output signals from a typical reverberatory .........Page 566
Rhythmical Signal Output......Page 567
Automatic Short-­Term Adjustment of Pathway Sensitivity by the Fatigue Mechanism. Those neuronal pathways that are overused usua.........Page 568
Tactile Receptors. There are at least six entirely different types of tactile receptors, but many more similar to these also exi.........Page 570
Detection of Vibration. All tactile receptors are involved in detection of vibration, although different receptors detect differ.........Page 571
Anatomy of the Dorsal Column–Medial Lemniscal System......Page 572
Spatial Orientation of the Nerve Fibers in the Dorsal Column–Medial Lemniscal System......Page 573
Somatosensory Areas I and II. Figure 48-­6 shows two separate sensory areas in the anterior parietal lobe called somatosensory a.........Page 574
Layers of the Somatosensory Cortex and Their Function......Page 575
Functions of Somatosensory Area I......Page 576
Two-­Point Discrimination. A method frequently used to test tactile discrimination is to determine a person’s so-­called “two-­p.........Page 577
Vibratory Sensation. Vibratory signals are rapidly repetitive and can be detected as vibration up to 700 cycles/sec. The higher .........Page 578
Processing of Position Sense Information in the ­Dorsal Column–Medial Lemniscal Pathway. Referring to ­Figure 48-­12, one sees t.........Page 579
Transmission of Sensory Signals in the Anterolateral Pathway......Page 580
Rate of Tissue Damage as a Stimulus for Pain. The average person begins to perceive pain when the skin is heated above 45°C, as .........Page 583
Dual Pathways for Transmission of Pain Signals Into the Central Nervous System......Page 584
Paleospinothalamic Pathway for Transmitting Slow-­Chronic Pain......Page 585
Pain Suppression (Analgesia) System in the Brain and Spinal Cord......Page 586
The Brain’s Opiate System—Endorphins and Enkephalins......Page 587
Visceral Pain......Page 588
Localization of Referred Pain Transmitted via Visceral Pathways. When visceral pain is referred to the surface of the body, the .........Page 589
Stimulation of Thermal Receptors—Sensations of Cold, Cool, Indifferent, Warm, and Hot. Figure 49-­10 shows the effects of differ.........Page 592
Spatial Summation of Thermal Sensations. Because the number of cold or warmth endings in any one surface area of the body is sli.........Page 593
Physical Principles of Optics......Page 594
Consideration of All Refractive Surfaces of the Eye as a Single Lens—The “Reduced” Eye. If all the refractive surfaces of the ey.........Page 597
Pupillary Diameter......Page 598
Clinical Method for Stating Visual Acuity. The chart for testing eyes usually consists of letters of different sizes placed 20 f.........Page 601
Fluid System of the Eye—Intraocular Fluid......Page 602
Intraocular Pressure......Page 603
The Retina Is Composed of Ten Layers or Boundaries. Figure 51-­1 shows the functional components of the retina, which are arrang.........Page 605
Rods and Cones Are Essential Components of Photoreceptors. Figure 51-­3 is a diagrammatic representation of the essential compon.........Page 606
Rhodopsin and Its Decomposition by Light Energy. The outer segment of the rod that projects into the pigment layer of the retina.........Page 607
Role of Vitamin A for Formation of Rhodopsin. Note in Figure 51-­5 that there is a second chemical route whereby all-­trans reti.........Page 608
Mechanism Whereby Rhodopsin Decomposition Decreases Membrane Sodium Conductance—The Excitation “Cascade.” Under optimal conditio.........Page 609
Photochemistry of Color Vision by the Cones......Page 610
Interpretation of Color in the Nervous System. In Figure 51-­10, one can see that an orange monochromatic light with a wavelengt.........Page 611
Neural Function of the Retina......Page 612
Neurotransmitters Released by Retinal Neurons. Not all the neurotransmitter chemical substances used for synaptic transmission i.........Page 613
Depolarizing and Hyperpolarizing Bipolar Cells......Page 614
P and M Cells. In primates, a different classification of retinal ganglion cells is used, and as many as 20 types of retinal gan.........Page 615
Transmission of Signals Depicting Contrasts in the Visual Scene—The Role of Lateral Inhibition......Page 616
Transmission of Color Signals by the Ganglion Cells......Page 617
Visual Pathways......Page 618
Primary Visual Cortex. The primary visual cortex (see Figure 52-­2) lies in the calcarine fissure area, extending forward from t.........Page 619
Interaction of Visual Signals From the Two Separate Eyes. Recall that visual signals from the two separate eyes are relayed thro.........Page 620
Detection of Lines of Specific Lengths, Angles, or Other Shapes. Some neurons in the outer layers of the primary visual columns,.........Page 621
Muscular Control of Eye Movements. The eye movements are controlled by three pairs of muscles, shown in Figure 52-­7: (1) the me.........Page 622
Fixation Movements of the Eyes......Page 623
Superior Colliculi Are Mainly Responsible for Turning the Eyes and Head Toward a Visual Disturbance. Even after the visual corte.........Page 624
Autonomic Nerves to the Eyes......Page 625
Control of Pupillary Diameter......Page 626
53 - The Sense of Hearing......Page 628
Umami Taste. Umami, a Japanese word meaning “delicious,” designates a pleasant taste sensation that is qualitatively different f.........Page 639
Location of the Taste Buds. The taste buds are found on three types of papillae of the tongue, as follows (see Figure 54-­1A): (.........Page 640
Generation of Nerve Impulses by the Taste Bud. On first application of the taste stimulus, the rate of discharge of the nerve fi.........Page 641
Rapid Adaptation of Taste. Everyone is familiar with the fact that taste sensations adapt rapidly, often almost completely, with.........Page 642
Mechanism of Excitation of the Olfactory Cells. The portion of each olfactory cell that responds to the olfactory chemical stimu.........Page 643
Affective Nature of Smell. Smell, even more so than taste, has the affective quality of either pleasantness or unpleasantness, a.........Page 644
The Primitive Olfactory System—The Medial ­Olfactory Area. The medial olfactory area consists of a group of nuclei located in th.........Page 645
Centrifugal Control of Activity in the Olfactory Bulb by the Central Nervous System. Many nerve fibers that originate in the olf.........Page 646
Anterior Motor Neurons. Located in each segment of the anterior horns of the cord gray matter are several thousand neurons that .........Page 647
Muscle Sensory Receptors—Muscle Spindles and Golgi Tendon Organs—and Their Roles in Muscle Control......Page 648
Division of the Intrafusal Fibers Into Nuclear Bag and Nuclear Chain Fibers—Dynamic and Static Responses of the Muscle Spindle. .........Page 649
Neuronal Circuitry of the Stretch Reflex. Figure 55-­5 demonstrates the basic circuit of the muscle spindle stretch reflex, show.........Page 650
The Muscle Spindle System Stabilizes Body Position During Tense Action. One of the most important functions of the muscle spindl.........Page 651
Golgi Tendon Organ Helps Control Muscle Tension. The Golgi tendon organ, shown in Figure 55-­8, is an encapsulated sensory recep.........Page 652
Flexor Reflex and the Withdrawal Reflexes......Page 653
Neuronal Mechanism of the Flexor Reflex. The left-­hand portion of Figure 55-­9 shows the neuronal pathways for the flexor refle.........Page 654
Cord “Righting” Reflexes. When a spinal animal is laid on its side, it will make uncoordinated movements to try to raise itself .........Page 655
Diagonal Stepping of All Four Limbs—“Mark Time” Reflex. If a well-­healed spinal animal (with spinal transection in the neck abo.........Page 656
Primary Motor Cortex......Page 658
Supplementary Motor Area......Page 659
Corticospinal (Pyramidal) Tract......Page 660
Somatosensory Feedback to the Motor Cortex Helps Control Precision of Muscle Contraction......Page 662
Patterns of Movement Elicited by Spinal Cord Centers. From Chapter 55, recall that the spinal cord can provide certain specific .........Page 663
Medullary Reticular System Transmit Inhibitory Signals. The medullary reticular nuclei transmit inhibitory signals to the same a.........Page 664
Vestibular Apparatus......Page 665
Semicircular Ducts. The three semicircular ducts in each vestibular apparatus, known as the anterior, posterior, and lateral (ho.........Page 666
Detection of Head Rotation by the Semicircular Ducts......Page 667
The Cerebellum and its Motor Functions......Page 671
Neuronal Circuit of the Functional Unit. Also shown in the left half of Figure 57-­7 is the neuronal circuit of the functional u.........Page 674
Turn-­On/Turn-­Off and Turn-­Off/Turn-­On Output Signals From the Cerebellum......Page 675
The Purkinje Cells “Learn” to Correct Motor Errors—Role of the Climbing Fibers......Page 676
Spinocerebellum—Feedback Control of Distal Limb Movements via the Intermediate Cerebellar Cortex and the Interposed Nucleus......Page 677
Cerebrocerebellum—Function of the Large Lateral Zone of the Cerebellar Hemisphere to Plan, Sequence, and Time Complex Movements......Page 678
Extramotor Predictive Functions of the Cerebrocerebellum. The cerebrocerebellum (the large lateral lobes) also helps to “time” e.........Page 679
Neural Pathways of the Putamen Circuit. Figure 57-­11 shows the principal pathways through the basal ganglia for executing learn.........Page 680
Spinal Level......Page 684
What drives us to action......Page 685
Physiologic Anatomy of the Cerebral Cortex......Page 687
Functions of Specific Cortical Areas......Page 688
Wernicke’s Area Is Important for Language Comprehension. The major area for language comprehension, called Wernicke’s area, lies.........Page 689
Area for Recognition of Faces......Page 690
Concept of the Dominant Hemisphere......Page 691
Role of Language in the Function of Wernicke’s Area and in Intellectual Functions......Page 692
Elaboration of Thought, Prognostication, and Performance of Higher Intellectual Functions by the Prefrontal Areas—Concept of a “.........Page 693
Thoughts, Consciousness, and Memory......Page 695
Short-­Term Memory......Page 696
Mechanism for Facilitation. In the case of facilitation, at least part of the molecular mechanism is believed to be the followin.........Page 697
Rehearsal Enhances the Transference of Short-­Term Memory Into Long-­Term Memory. Studies have shown that rehearsal of the same .........Page 698
Hippocampi Are Not Important in Reflexive Learning. People with hippocampal lesions usually do not have difficulty in learning p.........Page 699
Excitation of the Reticular Excitatory Area by Peripheral Sensory Signals. The level of activity of the reticular excitatory are.........Page 701
Neurohormonal Systems in the Human Brain. Figure 59-­3 shows the brain stem areas in the human brain for activating four neuroho.........Page 702
Limbic System......Page 704
Cardiovascular Regulation. Stimulation of different areas throughout the hypothalamus can cause many neurogenic effects on the c.........Page 705
Regulation of Uterine Contractility and Milk Ejection from the Breasts. Stimulation of the paraventricular nuclei causes their n.........Page 706
Hypothalamic Control of Circadian Rhythms—The Suprachiasmatic Nucleus. The suprachiasmatic nucleus (SCN) of the hypothalamus con.........Page 707
Effects Caused by Stimulation of the Hypothalamus. In addition to the vegetative and endocrine functions of the hypothalamus, st.........Page 708
Functions Of The Hippocampus......Page 709
Slow-­Wave Sleep......Page 713
Lesions in Sleep-­Promoting Centers Can Cause Intense Wakefulness. Discrete lesions in the raphe nuclei lead to a high state of .........Page 714
Cycle Between Sleep and Wakefulness......Page 715
General Organization of the Autonomic Nervous System......Page 723
Cholinergic and Adrenergic Fibers—Secretion of Acetylcholine or Norepinephrine......Page 725
Synthesis of Norepinephrine, Its Removal, and Its Duration of Action. Synthesis of norepinephrine begins in the axoplasm of the .........Page 726
Alpha and Beta Adrenergic Receptors......Page 727
Function of the Adrenal Medullae......Page 730
Effect of Loss of Sympathetic or Parasympathetic Tone After Denervation. Immediately after a sympathetic or parasympathetic nerv.........Page 731
The Parasympathetic System Usually Causes Specific Localized Responses. Control functions by the parasympathetic system are ofte.........Page 733
Control of Brain Stem Autonomic Centers by Higher Areas. Signals from the hypothalamus and even from the cerebrum can affect act.........Page 734
Excesses of CO2 or H+ Concentration Increase Cerebral Blood Flow. An increase in CO2 concentration in the arterial blood perfusi.........Page 736
Oxygen Deficiency as a Regulator of Cerebral Blood Flow. Except during periods of intense brain activity, the rate of O2 utiliza.........Page 737
Cerebral Microcirculation......Page 738
Cerebrospinal Fluid System......Page 739
Absorption of Cerebrospinal Fluid Through the Arachnoidal Villi. The arachnoidal villi are microscopic fingerlike inward project.........Page 740
Lymphatic Function of the Perivascular Spaces. As is true elsewhere in the body, a small amount of protein leaks out of the brai.........Page 741
Brain Metabolism......Page 742
Under Normal Conditions, Most Brain Energy Is Supplied by Glucose. Under normal conditions, almost all the energy used by the br.........Page 743
“Slow Waves” Caused by Undulating Changes in Resting Membrane Potential. Most gastrointestinal contractions occur rhythmically, .........Page 744
Spike Potentials. The spike potentials are true action potentials. They occur automatically when the resting membrane potential .........Page 745
Neural Control of Gastrointestinal Function—Enteric Nervous System......Page 746
Parasympathetic Stimulation Increases Activity of the Enteric Nervous System. The parasympathetic supply to the gut is divided i.........Page 747
Hormonal Control of Gastrointestinal Motility......Page 748
Peristaltic Waves Move Toward the Anus With Downstream Receptive Relaxation—“Law of the Gut.” Peristalsis, theoretically, can oc.........Page 750
Mechanisms of Increased Blood Flow During Gastrointestinal Activity. Although the precise causes of the increased blood flow dur.........Page 751
“Countercurrent” Blood Flow in the Villi. Note in Figure 63-­8 that the arterial flow into the villus and the venous flow out of.........Page 752
Importance of Nervous Depression of Gastrointestinal Blood Flow When Other Parts of the Body Need Extra Blood Flow. A major valu.........Page 753
Voluntary Stage of Swallowing. When the food is ready for swallowing, it is “voluntarily” squeezed or rolled posteriorly into th.........Page 754
The Pharyngeal Stage of Swallowing Momentarily Interrupts Respiration. The entire pharyngeal stage of swallowing usually occurs .........Page 755
Motor Functions of the Stomach......Page 756
Stomach Emptying......Page 757
The Hormone Gastrin Promotes Stomach Emptying. In Chapter 65, we discuss how stretching of the stomach wall and the presence of .........Page 758
Movements of the Small Intestine......Page 759
Powerful, Rapid Peristalsis—“Peristaltic Rush.” Although peristalsis in the small intestine is normally weak, intense irritation.........Page 760
Propulsive Movements—“Mass Movements.” Much of the propulsion in the cecum and ascending colon results from the slow but persist.........Page 761
Defecation......Page 762
Other Autonomic Reflexes That Affect Bowel Activity......Page 763
Contact of Food With Gut Epithelium Activates the Enteric Nervous System and Stimulates Secretion......Page 764
Secretion of Organic Substances. Although all the basic mechanisms by which glandular cells function are not known, experimental.........Page 765
Saliva Contains a Serous Secretion and a Mucus Secretion. The principal glands of salivation are the parotid, submandibular, and.........Page 766
Basic Mechanism of Hydrochloric Acid Secretion. When stimulated, the parietal cells secrete an acid solution that contains about.........Page 768
Secretion of Intrinsic Factor by Parietal Cells. The substance intrinsic factor, which is essential for vitamin B12 absorption i.........Page 769
Regulation of Pepsinogen Secretion......Page 770
Pancreatic Secretion......Page 771
Secretion of Bicarbonate Ions......Page 772
Secretin Stimulates Copious Secretion of Bicarbonate Ions, Which Neutralizes Acidic Stomach Chyme. Secretin is a polypeptide con.........Page 773
Bile Secretion by the Liver......Page 774
Composition of Bile. Table 65-­2 lists the composition of bile when it is first secreted by the liver and then after it has been.........Page 775
Cholecystokinin Stimulates Gallbladder Emptying. When food begins to be digested in the upper gastrointestinal tract, the gallbl.........Page 776
Secretion of Mucus by Brunner's Glands in the Duodenum......Page 777
Secretion of Mucus by The Large Intestine......Page 778
Carbohydrate Foods of the Diet. Only three major sources of carbohydrates exist in the normal human diet. They are sucrose, whic.........Page 780
Digestion of Proteins in the Stomach. Pepsin, an important peptic enzyme of the stomach, is most active at a pH of 2.0 to 3.0 an.........Page 781
Fats of the Diet. By far the most abundant fats of the diet are the neutral fats, also known as triglycerides, each molecule of .........Page 782
Digestion of Cholesterol Esters and Phospholipids. Most cholesterol in the diet is in the form of cholesterol esters, which are .........Page 783
Anatomical Basis of Absorption......Page 784
Sodium Is Actively Transported Through the Intestinal Membrane. Twenty to 30 grams of sodium are secreted in the intestinal secr.........Page 785
Secretion of Bicarbonate and Absorption of Chloride Ions in the Ileum and Large Intestine. The epithelial cells on the surfaces .........Page 786
Glucose Is Transported by a Sodium Co-­Transport Mechanism. In the absence of sodium transport through the intestinal membrane, .........Page 787
Absorption in the Large Intestine: Formation of Feces......Page 788
Composition of the Feces. The feces normally are about three-­fourths water and one-­fourth solid matter that is composed of abo.........Page 789
67 - Physiology of Gastrointestinal Disorders......Page 790
68 - Metabolism of Carbohydrates and Formation of Adenosine Triphosphate......Page 797
Transport of Triglycerides and Other Lipids From the Gastrointestinal Tract by Lymph—the Chylomicrons......Page 807
70 - Protein Metabolism......Page 819
71 - The Liver......Page 825
ENERGY INTAKE AND OUTPUT BALANCED UNDER STEADY-­STATE CONDITIONS......Page 831
The Hypothalamus Contains Hunger and Satiety Centers. Several neuronal centers of the hypothalamus participate in the control of.........Page 833
Neurons and Neurotransmitters in the ­Hypothalamus That Stimulate or Inhibit Feeding. Two distinct types of neurons in the arcua.........Page 834
Oral Receptors Meter Food Intake. When an animal with an esophageal fistula is fed large quantities of food, even though this fo.........Page 836
Feedback Signals From Adipose Tissue Regulate Food Intake.......Page 837
Importance of Having Both Long-­ and Short-­Term Regulatory Systems for Feeding......Page 838
73 - Energetics and Metabolic Rate......Page 847
Heat Production......Page 854
Radiation Causes Heat Loss in the Form of Infrared Rays. As shown in Figure 74-­4, in a nude person sitting inside at normal roo.........Page 855
Clothing Reduces Conductive and Convective Heat Loss. Clothing entraps air next to the skin in the weave of the cloth, thereby i.........Page 856
Mechanism of Sweat Secretion. In Figure 74-­5, the sweat gland is shown to be a tubular structure consisting of two parts: (1) a.........Page 857
Regulation of Body Temperature—Role of the Hypothalamus......Page 858
Temperature-­Increasing Mechanisms When the Body Is Too Cold......Page 859
Increased Thyroxine Output as a Long-­Term Cause of Increased Heat Production. Cooling the anterior hypothalamic-­preoptic area .........Page 860
Skin Temperature Can Slightly Alter the Set Point for Core Temperature Control......Page 861
Resetting the Hypothalamic Temperature-­Regulating Center in Febrile Diseases—Effect of Pyrogens......Page 862
Fever Caused by Brain Lesions. When a brain surgeon operates in the region of the hypothalamus, severe fever almost always occur.........Page 863
Chemical Structure and Synthesis of Hormones......Page 866
Amine Hormones Are Derived From Tyrosine. The two groups of hormones derived from tyrosine, the thyroid and the adrenal medullar.........Page 867
Cyclical Variations Occur in Hormone Release. Superimposed on the negative and positive feedback control of hormone secretion ar.........Page 870
Hormone Receptors and their Activation......Page 871
G Protein–Linked Hormone Receptors. Many hormones activate receptors that indirectly regulate the activity of target proteins (e.........Page 872
Enzyme-­Linked Hormone Receptors. Some receptors, when activated, function directly as enzymes or are closely associated with en.........Page 873
Adenylyl Cyclase–cAMP Second Messenger System......Page 874
Cell Membrane Phospholipid Second Messenger System......Page 875
Thyroid Hormones Increase Gene Transcription in the Cell Nucleus......Page 876
76 - Pituitary Hormones and Their Control by the Hypothalamus......Page 879
Hypothalamus Controls Pituitary Secretion......Page 880
Physiological Functions of Growth Hormone......Page 882
Growth Hormone Promotes Protein Deposition in Tissues......Page 883
Necessity of Insulin and Carbohydrate for the Growth-­Promoting Action of Growth Hormone......Page 884
Hypothalamic Growth Hormone–Releasing Hormone Stimulates, and Somatostatin Inhibits Growth Hormone Secretion......Page 886
Posterior Pituitary Gland and its Relation to the Hypothalamus......Page 888
Regulation of Antidiuretic Hormone Production......Page 889
Physiological Functions of Oxytocin......Page 890
Synthesis and Secretion of the Thyroid Metabolic Hormones......Page 891
Formation and Secretion of Thyroglobulin by the Thyroid Cells. The thyroid cells are typical protein-­secreting glandular cells,.........Page 892
Storage of Thyroglobulin.The thyroid gland is unusual among the endocrine glands in its ability to store large amounts of hormon.........Page 893
Thyroid Hormones Activate Nuclear Receptors. Thyroid hormone receptors are either attached to the DNA genetic strands or located.........Page 894
Effect on Plasma and Liver Fats. Increased thyroid hormone decreases the concentrations of cholesterol, phospholipids, and trigl.........Page 896
Effect on the Function of the Muscles.A slight increase in thyroid hormone usually makes the muscles react with vigor but, with .........Page 897
Cyclic Adenosine Monophosphate Mediates the Stimulatory Effect of TSH. Most of the varied effects of TSH on the thyroid cell res.........Page 898
The Adrenal Cortex has Three Distinct Layers......Page 904
Aldosterone Is the Major Mineralocorticoid Secreted by the Adrenals. In humans, aldosterone exerts nearly 90% of the mineralocor.........Page 907
Excess Aldosterone Increases Extracellular Fluid Volume and Arterial Pressure But Has Only a Small Effect on Plasma Sodium Conce.........Page 908
Excess Aldosterone Increases Tubular Hydrogen Ion Secretion and Causes Alkalosis. Aldosterone not only causes potassium to be se.........Page 909
Stimulation of Gluconeogenesis. The best-­known metabolic effect of cortisol and other glucocorticoids on metabolism is the abil.........Page 911
Mobilization of Fatty Acids. In much the same manner that cortisol promotes amino acid mobilization from muscle, it also promote.........Page 912
Anti-­inflammatory Effects of High Levels of Cortisol......Page 913
Cortisol Causes Resolution of Inflammation. Even after inflammation has become well established, administration of cortisol can .........Page 914
Chemistry of ACTH. ACTH has been isolated in pure form from the anterior pituitary. It is a large polypeptide, having a chain le.........Page 915
Summary of the Cortisol Control System......Page 916
Synthesis and Secretion of ACTH in Association With Melanocyte-­Stimulating Hormone, Lipotropin, and Endorphin......Page 917
Insulin and its Metabolic Effects......Page 922
Insulin Promotes Muscle Glucose Uptake and Metabolism......Page 924
Insulin Promotes Conversion of Excess Glucose Into Fatty Acids and Inhibits Gluconeogenesis in the Liver. When the quantity of g.........Page 925
Insulin Deficiency Increases Use of Fat for Energy......Page 926
Insulin Promotes Protein Synthesis and Storage......Page 927
Mechanisms of Insulin Secretion......Page 928
Feedback Relation Between Blood Glucose Concentration and the Insulin Secretion Rate. As blood glucose concentration rises above.........Page 929
Increased Blood Glucose Inhibits Glucagon Secretion. Blood glucose concentration is by far the most potent factor that controls .........Page 931
Summary of Blood Glucose Regulation......Page 932
Overview of Calcium and Phosphate Regulation in Extracellular Fluid and Plasma......Page 939
Intestinal Absorption and Fecal Excretion of Calcium and Phosphate. The usual rates of intake are approximately 1000 mg/day each.........Page 940
Bone and its Relationship to Extracellular Calcium and Phosphate......Page 941
Mechanism of Bone Calcification. The initial stage in bone production is secretion of collagen molecules (called collagen monome.........Page 942
Resorption of Bone—Function of the Osteoclasts. Bone is also being continually resorbed in the presence of osteoclasts, which ar.........Page 943
Control of the Rate of Bone Deposition by Bone “Stress” Bone is deposited in proportion to the compressional load that the bone .........Page 944
Cholecalciferol Is Converted to 25-­Hydroxycholecal­ciferol in the Liver. The first step in the activation of cholecalciferol is.........Page 945
Actions of Vitamin D......Page 946
Parathyroid Hormone......Page 947
Rapid Phase of Calcium and Phosphate Mobilization From Bone—Osteolysis. When large quantities of PTH are injected, calcium ion c.........Page 948
Cyclic Adenosine Monophosphate Mediates the Effects of Parathyroid Hormone. A large share of the effect of PTH on its target org.........Page 949
Increased Plasma Calcium Concentration Stimulates Calcitonin Secretion. The primary stimulus for calcitonin secretion is increas.........Page 950
Buffer Function of the Exchangeable Calcium in Bones—The First Line of Defense. The exchangeable calcium salts in the bones, dis.........Page 951
Dentin. The main body of the tooth is composed of dentin, which has a strong bony structure. Dentin is made up principally of hy.........Page 954
Mineral Exchange in Teeth. The salts of teeth, like those of bone, are composed of hydroxyapatite with adsorbed carbonates and v.........Page 955
Steps of Spermatogenesis......Page 958
Sex Chromosomes. In each spermatogonium, one of the 23 pairs of chromosomes carries the genetic information that determines the .........Page 959
Storage of Sperm in the Testes. The two testes of the human adult form up to 120 million sperm each day. Most of these sperm are.........Page 960
“Capacitation” of Spermatozoa Is Required for Fertilization of the Ovum......Page 961
Why Does Only One Sperm Enter the Oocyte With as many sperm as there are, why does only one enter the oocyte The reason is not e.........Page 962
Integration of the Male Sexual Act in the Spinal Cord. Although psychic factors usually play an important part in the male sexua.........Page 963
Emission and Ejaculation Are Functions of the Sympathetic Nerves. Emission and ejaculation are the culmination of the male sexua.........Page 964
Secretion, Metabolism, and Chemistry of the Male Sex Hormones......Page 965
Effect of Testosterone to Cause Descent of the Testes. The testes usually descend into the scrotum during the last 2 to 3 months.........Page 966
Testosterone Increases Bone Matrix and Causes Calcium Retention. After the great increase in circulating testosterone that occur.........Page 967
Gonadotropic Hormones: Luteinizing Hormone and Follicle-­Stimulating Hormone......Page 968
Role of Inhibin in Negative Feedback Control of Seminiferous Tubule Activity. When the seminiferous tubules fail to produce sper.........Page 969
Puberty and Regulation of Its Onset......Page 970
Female Hormonal System......Page 973
Monthly Ovarian Cycle and Function of Gonadotropic Hormones......Page 974
Development of Antral and Vesicular Follicles. During the first few days of each monthly female sexual cycle, the concentrations.........Page 976
Initiation of Ovulation. Figure 82-­6 provides a schema for the initiation of ovulation, showing the role of the large quantity .........Page 977
Estrogens. In the normal nonpregnant female, estrogens are secreted in significant quantities only by the ovaries, although minu.........Page 978
Synthesis of the Estrogens and Progestins. Note from the chemical formulas of the estrogens and progesterone in Figure 82-­7 tha.........Page 979
Effect of Estrogens on the Uterus and External Female Sex Organs. During childhood, estrogens are secreted only in minute quanti.........Page 980
Progesterone Promotes Secretory Changes in the Uterus. A major function of progesterone is to promote secretory changes in the u.........Page 981
Proliferative Phase (Estrogen Phase) of the Endometrial Cycle Occurs Before Ovulation. At the beginning of each monthly cycle, m.........Page 982
Regulation of Female Monthly Rhythm—Interplay Between Ovarian and Hypothalamic-­Pituitary Hormones......Page 983
Inhibin From the Corpus Luteum Inhibits FSH and LH Secretion. In addition to the feedback effects of estrogen and progesterone, .........Page 984
Menopause......Page 986
Stimulation of the Female Sexual Act. As is true in the male sexual act, successful performance of the female sexual act depends.........Page 987
Female Orgasm. When local sexual stimulation reaches maximum intensity, and especially when the local sensations are supported b.........Page 988
Entry of the Ovum Into the Fallopian Tube (Uterine Tube). When ovulation occurs, the ovum, along with a hundred or more attached.........Page 991
Anatomy and Function of the Placenta......Page 993
Diffusion of Oxygen Through the Placental Membrane. Almost the same principles for diffusion of oxygen through the pulmonary mem.........Page 994
Function of Human Chorionic Gonadotropin. Human chorionic gonadotropin is a glycoprotein having a molecular weight of about 39,0.........Page 995
Function of Estrogen in Pregnancy. In Chapter 82, we pointed out that estrogens exert mainly a proliferative function on most re.........Page 996
Effect of Fetal Hormones on the Uterus. The fetus’s pituitary gland secretes increasing quantities of oxytocin, which might play.........Page 1000
Stretch or Irritation of the Cervix. There is reason to believe that stretching or irritating the uterine cervix is particularly.........Page 1001
Estrogens Stimulate Growth of the Ductal System of the Breasts. All through pregnancy, the large quantities of estrogens secrete.........Page 1002
Prolactin Promotes Lactation......Page 1003
Suppression of the Female Ovarian Cycles in Nursing Mothers for Many Months After Delivery. In most nursing mothers, the ovarian.........Page 1004
Antibodies and Other Anti-­infectious Agents in Milk. Not only does milk provide the newborn baby with needed nutrients, but it .........Page 1005
84 - Fetal and Neonatal Physiology......Page 1006
85 - Sports Physiology......Page 1016
Normal Values for Selected Common Laboratory Measurements......Page 1028