Our Marvelous Bodies: An Introduction to the Physiology of Human Health

238 Pages·2008·0.981 MB·English

by  Gary F. Merrill M.D.

Our Marvelous Bodies

Our Marvelous Bodies
An Introduction to
the Physiology of Human Health
GARY F. MERRILL
RUTGERS UNIVERSITY PRESS
NEW BRUNSWICK, NEW JERSEY, AND LONDON
LIBRARY OF CONGRESS CATALOGING-IN-PUBLICATION DATA
Merrill, Gary F.
Our marvelous bodies : an introduction to the physiology of human health /
Gary F. Merrill.
p. cm.
Includes bibliographical references and index.
ISBN-: ----(hardcover : alk. paper)
.Human physiology.
[DNLM: .Physiological Processes. QT M ] I. Title.
QP..M 
—dc 
A British Cataloging-in-Publication record for this book is available
from the British Library.
Copyright © by Gary F. Merrill
All rights reserved
No part of this book may be reproduced or utilized in any form or by any means,
electronic or mechanical, or by any information storage and retrieval system, without
written permission from the publisher. Please contact Rutgers University Press, 
Joyce Kilmer Avenue, Piscataway, NJ ‒. The only exception to this
prohibition is “fair use” as defined by U.S. copyright law.
Visit our Web site: http://rutgerspress.rutgers.edu
Manufactured in the United States of America
CONTENTS
List of Figures ix
List of Tables xi
Preface xiii
1 The Foundation 1
Structure and Function 1
Homeostasis, Equilibrium, and the Steady State 7
Physiological Gradients 9
Physiological Reflexes 11
Control Systems Analysis 13
Feedback and Feedforward 15
2 Understanding the Mammalian Nervous System 18
What Are Neurons? 18
What Is the Nervous System? 19
Neuron Communication, Electrical and
Chemical Transmission 22
Different Neurotransmitters and Their Locations
and Functions 25
Discomfort, Pain, and the Nervous System 29
Mental Activity, Cerebral Blood Flow, and Health
of the Nervous System 32
3 The Endocrine System and Physiological
Communication 35
Advances in Endocrinology 35
Hormones, Proteins, and Peptides 39
The Hypothalamic-Pituitary Axis 41
Excesses and Deficiencies of GH and Health 44
The Adrenal Gland and Growth 47
The Thyroid Gland 48
v
vi CONTENTS
4 The Cardiovascular System and the Blood 53
The Blood 54
The Heart and Cardiac Cycle 57
The Blood Vessels 62
Lifestyle and Monitoring Cardiovascular Health 68
Reactive Hyperemia and Blood Flow to Organs and Tissues 72
5 Health and the Respiratory System 76
Components of the Respiratory System 77
Pulmonary Ventilation, or Lung Inflation and Deflation 80
Respiration, Exchange, and Transport of Blood Gases 83
Central and Peripheral Regulation of the Respiratory System 86
Lungs and Balance of Acids and Bases 89
Lifestyle and Care of the Lungs 92
6 Kidneys and Renal Physiology 94
Functional Morphology of the Kidneys 95
Glomerular Filtration Rate and Urine 96
Regulation of GFR and RPF 99
Reabsorption, Secretion, and the Formation of Urine 102
Renal Health, Hydration, and Urination 103
Diabetes and Sugar in the Urine 105
7 The Gastrointestinal System 109
Components of the Gastrointestinal (GI) or Enteric System 110
Mechanics and Reflexes of the GI Tract 113
Secretions of the GI Tract 115
Digestion of Carbohydrates, Fats, and Proteins 119
Health of the Oral Cavity and Vocalization 123
Health of the GI Tract and Diet 125
8 The Reproductive System 128
Gametogenesis, Genetic, Gonadal, and Phenotypic Sex 128
The Sexually Indifferent Embryonic Gonad 130
Spermatogenesis and the Male Reproductive System 132
Oogenesis, Folliculogenesis, and the Female Reproductive System 133
Sexually Transmitted Diseases (STDs), Sexual Behavior,
and Infertility 136
9 The Immune System 138
Cellular Defenses 138
Chemotaxis, Margination, Diapedesis, and Phagocytosis 140
Ports of Entry for Pathogens and the Reticuloendothelial
System (RES) 142
Immunity, Regenerative Medicine, and Stem Cells 145
CONTENTS vii
10 Muscle Function 151
Muscle Diversification 151
Excitation-Contraction Coupling in Muscle 153
Cycling of Cross-Bridges and Shortening of Sarcomeres 154
Muscle Levers, Hypertrophy, and Atrophy 156
Muscle Diseases and Conditions 158
Experimenting with Muscle 160
11 Integrated Physiological Responses 162
Hypovolemic Hypotension 162
Baroreceptor Reflexes and Cardiac Output 163
Vasomotor Responses and Blood Pressure 165
Renal Response and the Renin-Angiotensin System 166
Blood Flow and Its Distribution and Redistribution during
Hypotension 168
Long-Term Responses to Hypotension 168
12 For the Record 170
Blood Pressure and Your Health 172
Blood Lipids and Physical Activity 174
Blood Cells and Good Health 178
Blood Sugar, Diabetes, and Metabolic Syndrome 180
Glossary 185
Notes and Suggested Reading 199
Index 209

LIST OF FIGURES
1.1 Cardiac striated muscle structure 3
1.2 Relaxed versus contracted sarcomeres 4
1.3 Renal nephron 5
1.4 Components of a reflex arc 12
1.5 Components of a closed-loop feedback system 13
2.1 Autonomic nervous system 21
2.2 Functions of the cerebral cortex 25
2.3 Influence of various activities on cerebral blood flow 33
3.1 Modes of hormone action 36
3.2 Symptoms of thyroid diseases 51
4.1 Cylinder representing hematocrit 55
4.2 Pulmonary and systemic circulatory systems 63
4.3 Coronary reactive hyperemia 73
6.1 Renal pressure flow autoregulation 101
6.2 Renal handling of glucose 107
7.1 Transmural view of gut wall 111
9.1 Origins of blood cells 146
10.1 Excitation-contraction coupling in striated muscle 153
10.2 Cross bridges between thick and thin filaments 156
12.1 Author’s blood pressure over time 173
12.2 Author’s blood lipids over time 176
12.3 Author’s hematology over time 179
ix