The Autonomic Nervous System and Exercise

210 Pages·1990·4.346 MB·English

by  J. Hilary Green (auth.)

The Autonomie Nervous System
and Exercise
The Autonomie Nervous System
and Exereise
J. Hilary Green
Lecturer
Department of Human Movement and Recreation Studies
University of Western Australia
Springer-Science+Business Media, B.V.
©
1990 Springer Science+Business Media Dordrecht
Originally published by Chapman and Hall in 1990.
Softcover reprint ofthe hardcover 1st edition 1990
Typeset in l1/13pt Times by
EJS Chemical Composition,
Midsomer Norton, Bath
ISBN 978-0-412-32500-7 ISBN 978-1-4899-2919-8 (eBook)
DOI 10.1007/978-1-4899-2919-8
All rights reserved. No part of this book may
be reprinted or reproduced, or utilized in any
form or by any electronic, mechanical or other
means, now known or hereafter invented,
including photocopying and recording, or in
any information storage and retrieval system,
without permission in writing trom the
publisher.
British Library Cataloguing in Publication Data
Green, J. Hilary
The autonomie nervous system and exercise.
1. Man. Exercise. Physiological aspects.
1. Title
612'044
Ta my parents
Contents
Preface ix
1 Organization of the nervous system 1
1.1 The neurone 1
1.2 Synapses 3
1.3 The action potential 7
1.4 Organization of the nervous system 10
1.5 Central nervous system 12
1.6 Peripheral nervous system 25
References and further reading 30
2 Physiology of the autonomie nervous system 32
2.1 Neurotransmission 32
2.2 Noradrenaline 34
2.3 Adrenal medulla 42
2.4 Assessment of sympathoadrenal activity 42
2.5 Acetylcholine 49
2.6 Non-noradrenergic non-cholinergic neural transmitters 53
References and further reading 53
3 Neuromuscular function 56
3.1 Skeletal muscle 56
3.2 Control of movement: peripheral mechanisms 62
3.3 Control of movement: central mechanisms 66
3.4 Autonomie function during exercise 68
References and further reading 71
4 Energy metabolism 72
4.1 Energy for muscular contraction 72
4.2 Metabolie pathways 79
4.3 Anaerobic provision of ATP for muscular work 91
4.4 Aerobic provision for A TP for muscular work 94
4.5 The autonomie nervous system and metabolism 97
References and further reading 101
viii Contents
5 The cardiovascular and respiratory systems 104
A Cardiovascular responses to exercise 104
5.1 The heart 104
5.2 Blood flow 113
5.3 Origin of the stimulus for autonomic nervous activity
affecting the cardiovascular responses to exercise 116
5.4 Effect of autonomie nervous activity on the
cardiovascular responses to exercise 118
5.5 Recovery from exercise 125
B Respiration during exercise 126
5.6 Pulmonary ventilation 126
5.7 Tissue respiration 131
5.8 Oxygen consumption 134
References and further reading 139
6 Temperature regulation 142
6.1 Body temperature 142
6.2 Heat balance 143
6.3 Measurement of body temperature 150
6.4 Physiological control mechanisms 153
6.5 Autonomie nervous control of thermoregulatory
mechanisms and exercise 156
6.6 Models of thermoregulation 159
References and further reading 162
7 Factors affecting autonomie nervous activity 166
7.1 Ageing 166
7.2 Sex 169
7.3 Training 170
7.4 Drugs 172
References and further reading 174
8 Exereise and disease 178
8.1 Diabetes mellitus 178
8.2 Obesity 184
8.3 Atherosclerosis and ischaemic he art disease 187
References and further reading 195
Index 198
Preface
My main reason for writing a book on the role of the autonomie
nervous system in exereise is to present an integrative approach to
exereise physiology. Traditional textbooks on exereise physiology
use what might be deseribed as a systems approach. The inter
relationships between the systems, and therefore ehapters, is often
very diffieult for the undergraduate student to grasp. This is difficult
enough for a student of physiology. The problem is exaeerbated for
the sports seienee student who, in addition to studying applied
physiology, is faeed with other major diseiplines as diverse as
biomeehanies and soeiology. The present approach requires the
reader to link areas of physiology in order to see how the major
systems are all affeeted by autonomie neural eontrol during exercise.
The autonomie nervous system has been used as the link between the
physiologieal systems ehallenged by exercise, not only beeause of its
importanee, but also beeause this seems to be an area whieh is given
relatively little attention in tradition al textbooks of exereise
physiology.
The aim of Chapter 1 is to put the nervous system as a whole into
perspeetive. Chapter 2 then foeuses on the autonomie nervous system
and eonsiders its arrangement and physiology in detail. The third
ehapter diseusses the role of the neuromuseular system in human
movement, drawing attention to the roles of the eentral, peripheral
afferent, efferent motor and autonomie nervous systems. The next
three ehapters go on to examine three areas in detail: energy
metabolism, the eardiovaseular and respiratory systems, and
temperature regulation. These areas have been seleeted for their
signifieanee during exercise and beeause of the erueial importanee of
the autonomie nervous system in their eontro!. In eaeh ease resting
physiology is deseribed before the derangements eaused by exereise
are diseussed. The seventh ehapter ex amines some of the faetors
whieh affeet autonomie nervous aetivity during exereise, namely age,
sex, training and drugs. The final ehapter eonsiders the clinieal
x Preface
application of some of the applied physiology in the preceding
chapters. The written text of each chapter is supported by tables and
diagrams to elucidate the salient features.
The book is intended primarily for undergraduate and post
graduate students in sports science with a specialist interest in
exercise physiology. It is assumed that the reader will already have
studied some physiology and physiology of exercise, and therefore
this text is intended to supplement general textbooks and lecture
material. Since exercise physiology provides a good example of a
disturbance of homeostasis and the subsequent role of physiological
control mechanisms to restore equilibrium, it is hoped that this text
will also prove useful for students in medical and life sciences.
I would like to thank Dr I. A. Macdonald, Reader in Physiology at
the University of Nottingham, for his critical review of the first draft
of this manuscript.
I would also like to thank Martin Thomson, Department of
Anatomy and Human Biology, University of Western Australia, for
drawing the original diagrams.
Chapter 1
Organization of the nervous
system
1.1 The neurone
A nerve trunk comprises many single neurones (nerve ceHs). Thus,
the nerve ceH is the basic constituent of the nervous system (figure
1.1) and there are some 1 x 1012 neurones in the human nervous
system. The neurone comprises three distinct portions, the cell body,
the axon and the nerve terminal.
1.1.1 THE CELL BODY
.um
The ceH body of neurones ranges from 5-135 in diameter. In it
are located the nucleus, mitochondria, golgi apparatus and
endoplasmic reticulum. The nuc1eus consists of deoxyribonucleic acid
(DNA) and ribonucleic acid (RNA) which control cell division and
protein synthesis. The mitochondria have a vital role in the cell's
oxidative metabolism. The Golgi apparatus has a secretory function
and is continuous with the endoplasmic reticulum, a network of
tubules. There are two kinds of endoplasmic reticulum, rough and
smooth. The rough endoplasmic reticulum contains granules
composed of RNA which are involved in protein synthesis. The
smooth endoplasmic reticulum is concerned with steroid synthesis in
the gonads and with detoxification in liver ceHs. In skeletal musc1e
and cardiac ceHs, the smooth endoplasmic reticulum forms the
sarcoplasmic reticulum which plays a key role in musc1e contraction
(see section 3.1.3).
Arising from the ceH body are projections caHed dendrites.
Dendrites provide the receptive area of the ceH to the nerve endings