Cardiovascular Physiology book cover

Cardiovascular Physiology

Mosby Physiology Monograph Series (with Student Consult Online Access)

Cardiovascular Physiology gives you a solid understanding of how the cardiovascular system functions in both health and disease. Ideal for your systems-based curriculum, this title in the Mosby Physiology Monograph Series explains how the latest concepts apply to real-life clinical situations.

Paperback, 304 Pages

Published: December 2012

Imprint: Mosby

ISBN: 978-0-323-08697-4

Contents

  • vii

    CON T E N T S

    C H A P T E R 1

    OVERVIEW OF THE CIRCULATION

    AND BLOOD 1

    The Circulatory System 1

    Blood 5

    Erythrocytes 5

    Leukocytes 6

    Lymphocytes 7

    Blood Is Divided into Groups by Antigens

    Located on Erythrocytes 7

    Summary 9

    Case 1-1 9

    C H A P T E R 2

    EXCITATION: THE CARDIAC

    ACTION POTENTIAL . 11

    Cardiac Action Potentials Consist of Several

    Phases 11

    The Principal Types of Cardiac Action

    Potentials Are the Slow and Fast

    Types 12

    Ionic Basis of the Resting

    Potential 13

    The Fast Response Depends Mainly on

    Voltage-Dependent Sodium

    Channels 15

    Ionic Basis of the Slow Response 24

    Conduction in Cardiac Fibers Depends on

    Local Circuit Currents 25

    Conduction of the Fast Response 25

    Conduction of the Slow Response 27

    Cardiac Excitability Depends on the

    Activation and Inactivation of Specific

    Currents 27

    Fast Response 27

    Slow Response 28

    Effects of Cycle Length 28

    Summary 29

    Case 2-1 29

    C H A P T E R 3

    AUTOMATICITY: NATURAL

    EXCITATION OF THE HEART . 31

    The Heart Generates Its Own Pacemaking

    Activity 31

    Sinoatrial Node 32

    Ionic Basis of Automaticity 34

    Overdrive Suppression 35

    Atrial Conduction 36

    Atrioventricular Conduction 37

    Ventricular Conduction 39

    An Impulse Can Travel Around a Reentry

    Loop 41

    Afterdepolarizations Lead to Triggered

    Activity 42

    Early Afterdepolarizations 43

    Delayed Afterdepolarizations 43

    Electrocardiography Displays the Spread of

    Cardiac Excitation 44

    Scalar Electrocardiography 44

    Dysrhythmias Occur Frequently and

    Constitute Important Clinical

    Problems 47

    Altered Sinoatrial Rhythms 47

    Atrioventricular Transmission Blocks 48

    Premature Depolarizations 48

    Ectopic Tachycardias 49

    Fibrillation 49

    Summary 51

    Case 3-3 52

    C H A P T E R 4

    THE CARDIAC PUMP 55

    The Gross and Microscopic Structures of the

    Heart Are Uniquely Designed for Optimal

    Function 55

    The Myocardial Cell 55

    Structure of the Heart: Atria, Ventricles,

    and Valves 60

    The Force of Cardiac Contraction Is

    Determined by Excitation-Contraction

    Coupling and the Initial Sarcomere Length

    of the Myocardial Cells 63

    Excitation-Contraction Coupling Is

    Mediated by Calcium 63

    Mechanics of Cardiac Muscle 65

    The Sequential Contraction and Relaxation of

    the Atria and Ventricles Constitute the

    Cardiac Cycle 69

    Ventricular Systole 70

    Echocardiography Reveals Movement of

    the Ventricular Walls and of the

    Valves 73

    The Two Major Heart Sounds Are

    Produced Mainly by Closure of the

    Cardiac Valves 74

    The Pressure-Volume Relationships in the

    Intact Heart 75

    Passive or Diastolic Pressure-Volume

    Relationship 75

    Active or End-Systolic Pressure-Volume

    Relationship 77

    Pressure and Volume during the Cardiac

    Cycle: The P-V Loop 77

    Preload and Afterload during the Cardiac

    Cycle 77

    Contractility 78

    The Fick Principle Is Used to Determine

    Cardiac Output 79

    Summary 89

    Case 4-1 90

    C H A P T E R 5

    REGULATION OF THE

    HEARTBEAT 91

    Heart Rate is Controlled Mainly by the

    Autonomic Nerves 91

    Parasympathetic Pathways 92

    Sympathetic Pathways 93

    Higher Centers Also Influence Cardiac

    Performance 97

    Heart Rate Can Be Regulated via the

    Baroreceptor Reflex 97

    The Bainbridge Reflex and Atrial

    Receptors Regulate Heart Rate 98

    Respiration Induces a Common Cardiac

    Dysrhythmia 99

    Activation of the Chemoreceptor Reflex

    Affects Heart Rate 101

    Ventricular Receptor Reflexes Play a

    Minor Role in the Regulation of Heart

    Rate 102

    Myocardial Performance Is Regulated

    by Intrinsic Mechanisms 102

    The Frank-Starling Mechanism Is an

    Important Regulator of Myocardial

    Contraction Force 103

    Changes in Heart Rate Affect Contractile

    Force 107

    Myocardial Performance Is Regulated by

    Nervous and Humoral Factors 110

    Nervous Control 110

    Cardiac Performance Is Also Regulated by

    Hormonal Substances 113

    Summary 116

    Case 5-1 117

    C H A P T E R 6

    HEMODYNAMICS 119

    Velocity of the Bloodstream Depends on

    Blood Flow and Vascular Area 119

    Blood Flow Depends on the Pressure

    Gradient 120

    Relationship Between Pressure and Flow

    Depends on the Characteristics of the

    Conduits 122

    Resistance to Flow 125

    Resistances in Series and in Parallel 126

    Flow May Be Laminar or Turbulent 127

    Shear Stress on the Vessel Wall 128

    Rheologic Properties of Blood 129

    Summary 133

    Case 6-6 134

    C H A P T E R 7

    THE ARTERIAL SYSTEM . 135

    The Hydraulic Filter Converts Pulsatile Flow

    to Steady Flow 135

    Arterial Elasticity Compensates for the

    Intermittent Flow Delivered by the

    Heart 137

    The Arterial Blood Pressure Is Determined by

    Physical and Physiological Factors 140

    Mean Arterial Pressure 140

    Cardiac Output 142

    Peripheral Resistance 142

    Pulse Pressure 144

    Stroke Volume 144

    Arterial Compliance 145

    Total Peripheral Resistance and Arterial

    Diastolic Pressure 146

    The Pressure Curves Change in Arteries at

    Different Distances from the Heart 147

    Blood Pressure Is Measured by a

    Sphygmomanometer in Human

    Patients 148

    Summary 150

    Case 7-1 150

    C H A P T E R 8

    THE MICROCIRCULATION

    AND LYMPHATICS. 153

    Functional Anatomy 153

    Arterioles Are the Stopcocks of the

    Circulation 153

    Capillaries Permit the Exchange of Water,

    Solutes, and Gases 154

    The Law of Laplace Explains How

    Capillaries Can Withstand High

    Intravascular Pressures 155

    The Endothelium Plays an Active Role in

    Regulating the Microcirculation 156

    The Endothelium is at the Center of Flow-

    Initiated Mechanotransduction 157

    The Endothelium Plays a Passive Role in

    Transcapillary Exchange 158

    Diffusion Is the Most Important Means of

    Water and Solute Transfer Across the

    Endothelium 159

    Diffusion of Lipid-Insoluble Molecules Is

    Restricted to the Pores 159

    Lipid-Soluble Molecules Pass Directly

    Through the Lipid Membranes of the

    Endothelium and the Pores 162

    Capillary Filtration Is Regulated by the

    Hydrostatic and Osmotic Forces Across

    the Endothelium 163

    Balance of Hydrostatic and Osmotic

    Forces 165

    The Capillary Filtration Coefficient

    Provides a Method to Estimate the Rate

    of Fluid Movement Across the

    Endothelium 165

    Pinocytosis Enables Large Molecules to

    Cross the Endothelium 167

    The Lymphatics Return the Fluid and Solutes

    That Escape Through the Endothelium to

    the Circulating Blood 167

    Summary 168

    Case 8-1 169

    Case 8-2 169

    C H A P T E R 9

    THE PERIPHERAL CIRCULATION

    AND ITS CONTROL 171

    The Functions of the Heart and Large Blood

    Vessels 171

    Contraction and Relaxation of Arteriolar

    Vascular Smooth Muscle Regulate

    Peripheral Blood Flow 172

    Cytoplasmic Ca++ Is Regulated to Control

    Contraction, via MLCK 175

    Contraction Is Controlled by Excitation-

    Contraction Coupling and/or

    Pharmacomechanical Coupling 176

    Control of Vascular Tone by

    Catecholamines 178

    Control of Vascular Contraction by Other

    Hormones, Other Neurotransmitters,

    and Autocoids 178

    Intrinsic Control of Peripheral Blood

    Flow 179

    Autoregulation and the Myogenic

    Mechanism Tend to Keep Blood Flow

    Constant 179

    The Endothelium Actively Regulates Blood

    Flow 180

    Tissue Metabolic Activity Is the Main

    Factor in the Local Regulation of Blood

    Flow 181

    Extrinsic Control of Peripheral Blood Flow Is

    Mediated Mainly by the Sympathetic

    Nervous System 183

    Impulses That Arise in the Medulla

    Descend in the Sympathetic Nerves

    to Increase Vascular Resistance 183

    Sympathetic Nerves Regulate the

    Contractile State of the Resistance and

    Capacitance Vessels 184

    The Parasympathetic Nervous System

    Innervates Blood Vessels Only in the

    Cranial and Sacral Regions of the

    Body 185

    Epinephrine and Norepinephrine Are the

    Main Humoral Factors That Affect

    Vascular Resistance 185

    The Vascular Reflexes Are Responsible for

    Rapid Adjustments of Blood

    Pressure 185

    The Peripheral Chemoreceptors Are

    Stimulated by Decreases in Blood

    Oxygen Tension and pH and by

    Increases in Carbon Dioxide

    Tension 189

    The Central Chemoreceptors Are Sensitive

    to Changes in Paco2 189

    Other Vascular Reflexes 190

    Balance Between Extrinsic and Intrinsic

    Factors in Regulation of Peripheral Blood

    Flow 191

    Summary 192

    Case 9-1 194

    C H A P T E R 10

    CONTROL OF CARDIAC OUTPUT:

    COUPLING OF HEART AND

    BLOOD VESSELS . 195

    Factors Controlling Cardiac Output 195

    The Cardiac Function Curve Relates Central

    Venous Pressure (Preload) to Cardiac

    Output 196

    Preload or Filling Pressure of the

    Heart 196

    Cardiac Function Curve 196

    Factors That Change the Cardiac

    Function Curve 197

    The Vascular Function Curve Relates Central

    Venous Pressure to Cardiac Output 200

    Mathematical Analysis of the Vascular

    Function Curve 203

    Venous Pressure Depends on Cardiac

    Output 205

    Blood Volume 205

    Venomotor Tone 206

    Blood Reservoirs 206

    Peripheral Resistance 206

    Cardiac Output and Venous Return Are

    Closely Associated 207

    The Heart and Vasculature Are Coupled

    Functionally 207

    Myocardial Contractility 209

    Blood Volume 209

    Peripheral Resistance 210

    The Right Ventricle Regulates Not Only

    Pulmonary Blood Flow but Also Central

    Venous Pressure 211

    Heart Rate Has Ambivalent Effects on Cardiac

    Output 214

    Ancillary Factors Affect the Venous System

    and Cardiac Output 216

    Gravity 216

    Muscular Activity and Venous

    Valves 218

    Respiratory Activity 219

    Artificial Respiration 220

    Summary 221

    Case 10-1 221

    C H A P T E R 11

    CORONARY CIRCULATION . 223

    Functional Anatomy of the Coronary

    Vessels 223

    Coronary Blood Flow Is Regulated by

    Physical, Neural, and Metabolic

    Factors 225

    Physical Factors 225

    Neural and Neurohumoral Factors 227

    Metabolic Factors 228

    Diminished Coronary Blood Flow Impairs

    Cardiac Function 230

    Energy Substrate Metabolism During

    Ischemia 231

    Coronary Collateral Vessels Develop in

    Response to Impairment of Coronary

    Blood Flow 233

    Summary 235

    Case 11-1 236

     

    C H A P T E R 12

    SPECIAL CIRCULATIONS 237

    Cutaneous Circulation 237

    Skin Blood Flow Is Regulated Mainly by

    the Sympathetic Nervous System 237

    Ambient Temperature and Body

    Temperature Play Important Roles in

    the Regulation of Skin Blood

    Flow 239

    Skin Color Depends on the Volume and

    Flow of Blood in the Skin and on the

    Amount of O2 Bound to

    Hemoglobin 240

    Skeletal Muscle Circulation 240

    Regulation of Skeletal Muscle

    Circulation 240

    Cerebral Circulation 243

    Local Factors Predominate in the

    Regulation of Cerebral Blood

    Flow 243

    The Pulmonary and Systemic Circulations

    Are in Series with Each Other 245

    Functional Anatomy 245

    Pulmonary Hemodynamics 247

    Regulation of the Pulmonary

    Circulation 249

    The Renal Circulation Affects the Cardiac

    Output 250

    Anatomy 250

    Renal Hemodynamics 252

    The Renal Circulation Is Regulated by

    Intrinsic Mechanisms 252

    The Splanchnic Circulation Provides Blood

    Flow to the Gastrointestinal Tract, Liver,

    Spleen, and Pancreas 254

    Intestinal Circulation 254

    Hepatic Circulation 256

    Fetal Circulation 257

    Changes in the Circulatory System at

    Birth 259

    Summary 260

    Case 12-1 262

    Case 12-2 262

    Case 12-3 262

    C H A P T E R 13

    INTERPLAY OF CENTRAL AND

    PERIPHERAL FACTORS THAT

    CONTROL THE CIRCULATION 263

    Exercise 264

    Mild to Moderate Exercise 264

    Severe Exercise 268

    Postexercise Recovery 268

    Limits of Exercise Performance 269

    Physical Training and Conditioning 269

    Hemorrhage 269

    Hemorrhage Evokes Compensatory and

    Decompensatory Effects on the Arterial

    Blood Pressure 270

    The Compensatory Mechanisms Are

    Neural and Humoral 270

    The Decompensatory Mechanisms Are

    Mainly Humoral, Cardiac, and

    Hematologic 273

    The Positive and Negative Feedback

    Mechanisms Interact 275

    Summary 276

    Case 13-1 277

    Case 13-2 277

    APPENDIX: CASE STUDY

    ANSWERS . 279

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