The house of life : human physiology, with its applications to the preservation of health for use in classes and popular reading

Front matter

Med f

THE HOUSE OE LIEE j

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Preface

Numerous as are the works that have been published upon Elementary Physiology and upon Hygiene, as separate subjects, I am not aware that one exists at all resembling this volume, either in intention or arrangement. Indeed, I have been partly induced to write this little work by feeling the want of such an one to recommend for reading, when I have been lecturing to public audiences, or teaching classes of women in this subject. The distinctive feature of this book is that it not only treats of physiology, but, at the same moment, of health : its science is sufficiently full and precise to make it a suitable text-book for classes and students (whether preparing for the South Kensington first-stage examination or not), while at the same time the practical application of that science is everywhere shown, and the long preservation of a healthy life is taught by and through the structure of the House of Life. I am convinced that for popular study (that is to say.

PREFACE.

viii always, except in preparation for the medical profession) Physiology and Hygiene should be treated of together, and as related to each other. I am fully alive to the value of the study of any science, as a mental discipline ; but, at the same time, I believe that physiology is far above all other sciences as a subject that every person (and especially every woman) ought to obtain some knowledge of, just because it can be turned to so important a use in daily life — because the widespread knowledge of it will aid sanitation, and by making our people more healthy, will likewise make them more noble and more happy.

The Pronouncing Index is also a special feature, and is intended for the benefit of those who read this book without the advantage of oral teaching.

The two aims which I have kept before me in my work have been — to use language as simple, as transparently clear and unmistakeable in meaning, as possible ; and to show always the practical use of the science in its bearing upon daily life and personal health. To be told that I have succeeded in these respects is all the praise I could desire.

F. F. M.

Chapter I. Introductory

Who that has ever been ill can question that health is the one thing needful above all others for him upon this earth? One can be both happy and useful without wealth, without rank, without fame ; but even the toothache can mar happiness, and one cannot do one’s work properly while afflicted with “ only a cold.” We should expect, therefore, that all people would avoid everything which might take away from them the blessing of health, and would never neglect anything which would preserve it to them.

But when facts are consulted, they have a mournful tale to tell of lives wasted by ignorance and carelessness, and of suffering which need never have been endured. There meets us this startling fact, that there die in this country every year no fewer than one hundred ajid twenty thousand persons who are killed solely by neglect of the laws of health.^ And we must remember that even this great number is as nothing compared to the still larger one of those who throw away their health without actually losing life itself ; who undermine the foundations, and make breaches in the walls, and let decay creep into the chambers of “ this breathing house not made with hands,” by their neglect of its needs, long before it falls to the earth altogether.

^ The Report of the Medical Officer of the Privy Council, 1871 — the highest possible authority.

B

THE HOUSE OF LIFE.

This melancholy amount of preventible disease and death is a matter which concerns each one of us, not only individually, and upon far other than merely selfish grounds. For, leaving the personal suffering of a constant invalid out of the question (important though that is), it is the duty of every one towards his neighbour to guard his own health, that he may do his share of the work of the world, carry his due portion of its burdens, and increase the sum of its joys.

It is not meant that one’s own health should be the constant subject of one’s thoughts. The hypochondriac who weighs his food and measures his walks is generally selfish, and always silly, because his very caution defeats its object. But into absurdity of such a kind no one who works is likely to fall ; and as this little book has to show that activity, of both body and mind, is one of the most essential conditions of health, there is no fear that its study will lead to such a mistake.

If it is a duty which we owe to others to endeavour to preserve ow' oivn health, how infinitely more must it be the duty of those upon whom the responsibility for the health of othe7's rests, to acquaint themselves with the laws of life ? It is because women stand in this position, because upon them depend the healthful management of the home, and the bringing up of children, that it is so especially necessary that girls should be instructed in this subject.

There is but one useful plan upon which the laws of health can be studied. Many of those laws which are continually neglected are perfectly well known as rules to the people who disobey them. Such are — “ Breathe pure air,” and “ Wash and be clean.” The reason why such rules, which everybody knows, are so often disregarded, is that they are rules only. Very few people know why they exist. Their reasons and their importance can only be understood by aid of a knowledge of the

INTRODUCTORY.

structure of the human body ; to put it in large words, which people call “ scientific language,” — Human Physiology is the basis of Hygiene.

This is the only way in which health can be effectu ally studied. If we once understand just what mischief is worked upon our bodies by a certain kind of neglect, there is little fear of our being guilty of it ; on the other hand, mere rules, the object of which is not comprehended, stand a very poor chance of being practically minded.

Physiology is a science ; the preservation of health is an art founded upon that science. The science is in itself entrancingly interesting, and its study is full of value ; but this value is increased, and this interest is heightened, when its application to the prevention of disease is seen. We shall, therefore, here study the structure and the functions of this wonderful house of life, with its numerous apartments, and shall see what each part of the science of physiology can teach of the art of the preservation of health.

Let us begin by taking a brief outline sketch of the arrangement of the house. There is a wonderful combination of chambers and passages, of still-rooms and kitchens, workshops and offices, pulleys, pumps, and pipes ; yet the work of each department is done for the whole, the nerves being the messengers, and the blood the porter between one and another apartment.

Every organ does its own distinct work, yet always with reference to the wants of other parts. If we injure one portion of our bodies, in all probability some other will make a mighty effort to do double work. Any organ upon which extra work is thrown receives at once an additional supply of blood. There is sympathy and co-working throughout. Our duty with regard to our bodies is not to alter their already beautiful and perfect arrangements, but to protect them from injury, and to keep them in condi-

THE HOUSE OE LIFE.

tions favourable for their preservation ; just as, if we lived in a magnificent palace, with choice woods and marbles and precious stones decorating it everywhere, we should not attempt to alter it or amend it, according to our caprice, but would guard it from the entrance of those who would despoil it, and would watch that even our professing friends and our servants did it no harm.

I have already used a word which I must explain before going on farther — the word Organ. All nature is divided into two great classes — Organic Inorga7iic.

The first-named class comprises all animals and all vegetables ; the second consists of minerals, such as stones and metals, and also takes in water, air, etc. The term organ is applied to any distinct part of a body which has some special work of its own to do. Thus, in animals, the heart is the organ of the circulation of the blood, the brain is the organ of the mind, and so on. In vegetables, again, the leaves, the stalks, the flowers, are each and all organs, performing some special office for the life of the whole plant. But in rocks, in a clod of earth, in water, in fire, we do not find anything of the sort ; there are no separate parts performing separate functions. The animal and vegetable kingdoms are therefore organised ; the mineral kingdom is inorganic.

The bony skeleton forms a sort of foundation upon which the body is built ; the muscles and other tissues * being padded round the bone in the extremities, and the soft organs in the trunk and head being protected by cases of bone.

The bones forming the head and trunk are so arranged as to make two cavities, or tubes ; one consist-

^ A tissue is, to speak colloquially, the stuff of w'hich a part is made ; in other words, it is an elementary structure of the body — a structure which cannot be further divided without quite destroying its construction.

INTRODUCTOR V.

ing of the inside of the head and the inside of the backbone, the other of the inside of the trunk, which is partly enclosed by the ribs and the pelvis^ or basin, and covered over by the abdominal muscles.

Every one knows that the inside of the head is hollow, and that the brain is contained there ; it is not so generally known that there is also a hollow right down the middle of the backbone, and that the substance of the brain is continued in that canal, right down the spine. Such, however, is the fact. And the inside of the braincase and the inside of the spine together form the first of the two cavities, or tubes, into which the head and trunk of any animal that possesses a backbone (that is, every vertehrated animal) are divided.

The second cavity consists of the whole of the trunk, right round from the^ backbone. This space is closely packed with the delicate vital organs. It is divided into two parts by a large muscle, fibrous in the middle, called the diaphragm^ which forms an arch across the centre of the body, quite separating the organs which are above it from those which are below it. The use of this muscle is to assist in the act of breathing. The space above the diaphragm is called the thorax^ or chest ; that below it, the ahdomeit^ or belly.

Both the shape and the arrangement of the organs of the trunk are very similar in human beings and the lower animals. Those who can, therefore, should open and inspect a rabbit, or some other of our poor relations ; and should remember for the future that these creatures, whose structure is so like our own, are like us also in their bodily sensations and needs, so that he who starves or otherwise ill treats a beast is as criminal as though he had done likewise to one of his own species.

The heart and lungs will be found in the thorax ; and the diaphragm is pierced by the passing through it of large blood-pipes which leave the heart, as well as

THE HOUSE OF LIFE.

by the gullet, through which the food passes from the mouth to the stomach.

In the abdomen are the stomach, with the liver on its right, the spleen on its left, and the pancreas, or sweetbread, behind it. The coil of the intestines fills up most of the remaining space, and hides, from the front, the two kidneys, which are in the loins behind.

This introductory chapter must not conclude without explaining two words which will be repeatedly used in the book. The first one is

PHYSIOLOGY.

This comes from two Greek words, meaning literally “ The Science of Nature.” Human physiology treats of man’s body and its vital processes. The term anatomy is generally used to express an account of the mere structure of the system, and the word physiology is applied to the explanation of the functions of the parts. The latter term may, however, as you can see from its derivation, be made use of without incorrectness in treating of both structure and function — that is to say, of both how the body is made, and the work which its various parts have to do.

I'he next word which I must explain is

HYGIENE.

This is derived from the name of the goddess of health worshipped by the ancient Romans — Hygeia. The word is used by us to denote “ The Laws of Health.”

These definitions make it possible for the reader to thoroughly understand the power of the sentence which stands on a preceding page — “ Human Physiology is the basis of Hygiene.”

Chapter II. Respiration

There is no more important hygienic precept than “ Breathe pure air.” At the same time, there is no one which will more fully illustrate the truth that the only way to secure obedience to the laws of health is to explain the physiological principles upon which those laws are based. The reason why we should breathe pure air, and the importance to our health of our doing so, must be found by studying two of the vital processes — Respiration (that is, breathing), and the Circulation of the Blood.

The organs concerned in these two processes are the only ones in the thorax, or chest, and above the diaphragm. The lungs are the organs of respiration ; the heart is that of the circulation.

The heart lies in the centre of the chest, with its point directed toward the left, and one of the lungs is on either side of it (Fig. i).

The lungs (in the lower animals termed the lights) are two grayish-pink bodies, which extend from the collar-bone to just below the bottom of the shoulder-blade. The right lung is a little heavier than the left. The right also differs from the left lung by being divided into three portions, called lobes, by deep fissures, which go far down into its substance, while the left lung is divided in a similar manner into two lobes only.

Each lung is covered by a very delicate shining smooth membrane (that is, skin), named the pleura (Lat. plural,

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pleurd). The pleurae completely cover the lungs, and then turn backwards and line the inside wall of the chest, fastening below on to the diaphragm. Each pleura thus forms a shut bag, with only a little fluid inside the bag itself,

C ^ c >JV

EL

Fig. I. — The Heart, Great Vessels, and Lungs.

FRONT VIEW.

T, trachea, or windpipe ; LL, left lung ; RL, right lung, dissected out so as to show the divisions of the bronchus ; B, the bronchi ; RV, the right ventricle.; RA, the right auricle ; LA, the left auricle ; LV, the left ventricle ; PA, the pulmonary artery ; PV, the pulmonary veins (these veins and artery are shown entering the left lung, but have been removed in dissecting the right lung) ; VS, the vena cava superior; VI, the vena cava inferior, the two large veins through which the blood enters the right auricle ; A, the aorta, the great artery by which the blood leaves the left ventricle ; CC, carotid arteries ; RJV, LJV, right and left jugular veins. All the great vessels are cut off short, except the pulmonary artery and veins.

but with a lung wrapped up in one half of the outside and the other half of the outside affixed to the chest walls and diaphragm.

There are several instances in the body of fine skins forming shut bags in this manner. The most noteworthy one is the peritoneum.^ which is reflected so upon all the

RESFIRA TION.

organs of the abdomen ; and there is also such a bag covering the heart, and another one over the brain. They are called serous membranes ; and they all have between the two layers of the skin a very small quantity of fluid, called se7‘um.

The lungs are made up of the following structures : —

Firsts there are blood-vessels ; that is to say, pipes which have blood in them. Secondly^ there are air-tubes^ which I shall immediately describe more fully. These two kinds of pipes are supported and bound together by a substance called elastic tissue^ the name of which tells something about its powers. Finally, there are nerves and lymphatic vessels. The lung-substance is a combination of all these structures ; the air-pipes and the blood-vessels make up most of it.

All the air-tubes in the lungs are made out of one pipe — the windpipe.

If you lean your head back, you can feel a firm tube running right down the centre of your throat ; that is the trachea^ or windpipe. It is a pipe, about five inches long in a grown-up person, opening at the top into the back of the mouth. It is made of a series of rings. These are composed partly of cartilage (that is, gristle), which goes three-quarters of the way round ; but right at the back, the last quarter of the rings is a soft yielding substance. The reason for this is that if the rings were made entirely of the soft material, the sides of the pipe might fall together, so that the air could not pass down it, and then we should suffocate ; on the other hand, if the hard gristle were at the back of the windpipe, it would obstruct the passage of food into the stomach, since the gullet lies against the windpipe behind.

At its lower end, behind the breast-bone, the windpipe divides so as to form two branches, one of which goes into each lung. These two tubes are called the bronchi (Latin singular, bronchus) ; and the place where lO

THE IIGUTE OP LIFE.

each one enters its own lung, which is where the blood-vessels also enter, is named the root of the lung. As you will see in Fig. i, this is nearly in the middle of the organ.

As soon as each bronchus enters the lung, it in its turn divides into two other tubes ; then each one of these divides into two (or occasionally three) more, and each of those into two more again, and so on. To put it in other words : each bronchus, having gone into the lung substance, divides and makes two tubes ; then those two divide and make four ; and the four separate and make eight ; and this process of division and subdivision continues, till an immense number of air-tubes are made. These divisions of the bronchi are named the bi'onchial tubes.

Now, whenever one bronchial tube divides to make two others, the two are both nanvwer pipes, and 7?iade of thinner skin than the one was from which they are formed. Thus each bronchus is narrower, and made of finer skin than the windpipe ; and the two first bronchial tubes are narrower than the bronchus by the division of which they are made ; and so on. So that, finally, the last pipes produced in the lungs by this continual dividing and subdividing are only about one-fortieth of an inch in diameter, and are made of very delicate skin indeed.

Upon the end of every one of those smallest bronchial tubes there is a little swelling, shaped something like a funnel. The smallest bronchial tube may be compared to the stem of a funnel, and the dilation spreads out from it, as the mouth of a funnel, into which the liquid is poured, does upon its stem. But the dilation at the end of the bronchial tube is not quite smooth, like the top of a funnel ; on the contrary, the skin of which it is made bulges out inside into a great number of little pits or depressions, like small caverns in its walls. These tiny recesses are the air-cells. Fig. 2 will help you to understand this description.

RES PI R A TION.

1 1

You would find it very interesting to get the lungs (lights) of some animal from the butcher, and try how far you can trace the divisions of the bronchi.

If you purchased the two lungs still attached to the end of the windpipe, you might, before cutting them at all, blow through a hollow stem of some sort into the windpipe, and you would then see the lungs swell up, and sink down again when you removed your lips from the tube, just as the chestwall, which covers the lungs, rises and falls when we draw and send out our breath.

Did you ever wonder what caused that rise and fall of your chest? No doubt you know vaguely that it happens as you breathe ; but do you really know what breathing is ?

All around us there is an invisible something, which we can feel by waving our hands about in it, and the effects of which are often plainly enough to be seen. We call it, when it is still, the air, and when it is in a state of commotion, the wind. It is a substance, for it will keep apart the sides of a bladder that is full of it, and it will bear the weight of a kite up towards the sky. It is the same substance that we call breath, when it has been down into our lungs ; and the act of breathing is simply drawing the air down into the lungs and sending it out

Fig. 2.* — Air-Cells of Lungs

MAGNIFIED.

a, a, Smallest bronchial tubes, terminating in elongated dilatations (the air-sacs), upon which bulge out b, b, the air-cells.

*

From Kolliker.

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of them again. When the air is drawn in, the bronchial tubes are filled, the lungs expand and the chest rises ; when the air passes out the chest sinks down again.

The act of drawing in breath is Lispiration ; that of sending out breath is Expiration ; and the whole act of breathing is called Respiration.

Why we respire will be seen by and by ; I am now going on to explain the mechanism of breathing. The lungs do not breathe simply because they have in them all that multitude of air-pipes. The trachea, the bronchi, the bronchial tubes, and the air-cells, are the series of passages through which the air passes in the lungs ; but although the lungs of a dead animal have all these, yet it does not respire. If it drew breath we should know it was not dead.

We make the respiratory effort, by which breath is drawn into and pushed out of the lungs, without, necessarily, our will acting in the matter at all ; to put this in more precise terms — respiration is an involuntary action. Many of our most important vital processes are carried on thus, for the very obvious reason that if we had to give our own thoughts to their performance, and will them before they took place, we should be able to do nothing else but attend to our own bodily functions. Our brain proper, in which our will and our feeling are seated, does not, therefore, need to take thought of these things for us ; still, every organ acts through nerves, and there are special nerves to make the lungs, and the muscles connected with them, carry on their work incessantly.

The action which these respiratory nerves have to order is partly {a) that of the diaphragm, that large muscle which separates the chest from the abdomen, and partly {b) that of the muscles between the ribs. These are the chief portions of the machinery of breathing. The muscles which form the front of the abdomen also assist in the process.

RESPIRA TION.

Wherever in the body we find that elementary structure called muscular tissue^ it has always one peculiar power of its own. This power, which all muscle possesses, is that of becoming at one time thicker and shorter ; it shrinks together, and gains in thickness just as much as it loses in length.

Now, it has already been said that the lungs are fastened by the pleura on to the diaphragm as well as on to the chest-walls. We also know that the lungs are partly composed of elastic tissue^ a substance which receives its name from its having the same properties as elastic, — that is to say, it will stretch when some force is applied to it, and shrink back to its original size directly the force is removed.

The lungs have elastic tissue in them ; the diaphragm is made of muscular tissue. Let us see how they would act, without, for the moment, considering the muscles between the ribs or those of the abdomen.

The centre of the diaphragm is tendinous, and has not the power of contraction ; but all round its sides, just where the lungs are fastened on to it, it is made of muscle, and this contracts. The diaphragm, you remember, is shaped like an arch across the centre of the trunk of the body. When the muscular fibres of the sides of this arch all contract, becoming thicker and shorter^ it is clear that the arch must become flatter ; and in doing this it necessarily drags down the lungs, which are fastened to it, and puts their elastic tissue on the stretch ; the air-tubes are thus pulled open, and the air rushes into them to occupy the space so produced. But presently the diaphragm leaves off contracting; then the elastic tissue of the lungs, no longer kept upon the stretch by the pulling down of that muscular arch, does just as a piece of elastic outside the body would do when one left off pulling it — it returns to its original •size. But in doing so, it must press upon the air-

H

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cells and bronchial tubes, and squeeze out again from them some of that air which had space to come in when the elastic tissue was pulled down by the diaphragm.

Well, it may be said, this seems to explain the mechanism of breathing ; what need is there for the action of the muscles between the ribs, or those covering in the abdomen ?

In fact, some persons (the male sex in general) do breathe almost entirely with the diaphragm ; but, on the other hand, women usually breathe chiefly by the ribmuscles ; and, in all cases, the one method of expanding the lungs fits in with the other, and we breathe partly by the diaphragm, partly by the muscles between the ribs, which are called the intercostal (i.e. between-rib) muscles.

The ribs are fastened by joints of cartilage on to the spine behind, and on to the breast-bone in front, and the intercostal muscles run between the ribs, from each one to the next. One set of intercostals (called the exterftal) run obliquely toward the front, and another set (the internal) cross them, running obliquely backwards. By the contraction of the external intercostal muscles, the ribs are a little lifted up, and the breast-bone slightly pushed outwards, at the same moment that the diaphragm is contracting and pulling the lungs downwards. The effect of the movement of the ribs and breast-bone just mentioned is to make the lungs stretch from before backwards, as the diaphragm makes them stretch from above downwards, and the air rushes in to fill this space directly it is made.

The internal intercostals act in precisely the reverse manner, pressing the ribs downwards, and pulling the breast-bone a little inwards. They are, therefore, aids to expiration.

The abdominal muscles help to pull down the ribs, and to push up the diaphragm by squeezing on the

I^ESFJRA TION.

stomach and other organs, and pressing them against the contracted arch. They, therefore, help expiration^ and they come into play chiefly when we cough, or sneeze, or sigh, violently expelling air from our lungs.

Over and over again, as long as we live, these various parts of the respiratory mechanism perform their several actions. The diaphragm contracts and pulls the lungs downwards, and at the same moment the external intercostal muscles raise the ribs, and stretch the lungs crossways ; thus the air-vessels in the lungs are opened to their widest extent, and the air rushes into them. Then the action of the muscles just named ceases \ the elasticity of the lung tissue comes into play, the internal intercostal muscles contract and carry the ribs down again, and the diaphragm (aided by the pushing against its under side of the abdominal organs, by the muscles which cover them) returns to its arched-up shape ; thus the bronchial tubes are pressed upon, and the air, which was immediately before drawn in, is expelled again. Then there is an instant’s pause ; and then the whole proceeding begins again. This is respiration ; and in an adult the whole of these actions are repeated from fifteen to eighteen times in every minute.