EXPLANATION OF THE SUBJECT

1. What is the meaning of the word Physiology?HBH 9.1

This word is formed from two Greek words, phusis, nature, and lego, to discourse. It means a description of Nature.HBH 9.2

2. Of what does Physiology treat?HBH 9.3

It treats upon the purposes, uses, functions, actions, properties, results, and relations, of the various parts of the living body, in its healthy or normal condition. In other words, it is a description of organized or animate Nature, such as trees, plants, brute animals, and man.HBH 9.4

3. Into what branches is Physiology divided?HBH 9.5

Into Vegetable, Animal, and Human. When treating of plants and trees, it is Vegetable Physiology. When treating of brute animals, it is Animal Physiology. Human Physiology, or that relating particularly to man, is that which we shall treat upon in the following pages.HBH 9.6

4. What is Hygiene?HBH 9.7

The meaning of the word Hygiene, is health. As a study, Hygiene treats upon what will improve and preserve health, what will impair and destroy health, and what is best calculated to produce a healthy condition of the body.HBH 9.8

5. Does not a work of this kind embrace the subject of Anatomy?HBH 10.1

Anatomy treats upon the structure of living things, such as their color, size, form, surface, etc.HBH 10.2

6. Will this work, then, treat upon Anatomy?HBH 10.3

It will treat upon it only so far as it is connected with Physiology and Hygiene. We design to introduce, in each of these branches, only that which is of use to all classes of persons. The work then must contain something of Anatomy, more of Physiology, and much of Hygiene. These branches are so intimately related to each other, that we do not propose to separate them in this work, but to treat upon the structure, functions, and care of the different parts of the body as we pass along.HBH 10.4

7. What does man discover concerning his relation to surrounding objects, as he enters upon the study of himself?HBH 10.5

He discovers that his senses, feelings, and faculties, relate him to the whole universe. His well-being certainly demands that such relation should be the most harmonious. The world appears to him full of beauty, and he has eyes adapted to see it, and faculties just fitted to enjoy it. His ears are wonderfully adapted to all sounds, and their harmonious combination in music affords the most pleasing sensation. His sense of smell is related to a thousand delightful odors. His taste finds exquisite gratification from the aliments best adapted to supply the waste of his system. His sense of touch, variously modified in many organs of the body, gives him a world of delight.HBH 10.6

8. What benefit can we derive from the study of ourselves?HBH 11.1

It will discover to us, that man, in his nature and faculties, capabilities and conditions, and in his relations to the world in which he exists, is one of the most interesting and important subjects which the human mind has power and compass to investigate. This study also displays to us the wonderful wisdom of God in our formation, and teaches us how we can secure the greatest amount of happiness here, by showing us that true enjoyment in this world can only be secured by the greatest possible freedom from sickness and pain.HBH 11.2

9. How can such a study teach us the art of happiness?HBH 11.3

By teaching us what kind of food, air, and habits of life, will tend to make us sick; what kinds will preserve health; and how we can obtain cheerfulness, and freedom from that health-destroying disease, despondency of mind.HBH 11.4

10. What does Physiology discover to us concerning the mind?HBH 11.5

It discovers to us, that to properly understand and care for the mind, it is necessary to ascertain how far the mind is connected with the body; to what extent it is affected by the conditions of the body; and then, again, on what depend those conditions of the body which affect the mind. In order to this, the body itself must be understood in its animal and organic nature, its physical and vital properties and laws, and its physiological actions and affections. This will show us that mind and body are so closely connected that one is affected by the other. So that we cannot habitually possess lively and correct moral feelings, or a sound mind, unless we so live as to preserve a sound body; for true happiness may be properly defined as health of body and health of mind.HBH 11.6

11. How, then, does Physiology treat of the human body?HBH 12.1

As a system, composed of sub-systems, all being called the human system. The whole composed of dependent parts, acting upon each other, but all working together harmoniously.HBH 12.2

12. What, then, does man’s well-being here require?HBH 12.3

It requires a knowledge of himself, both mentally and physically, and also such a relation of himself to the elements of the external world, and such adaptation of these elements to his own condition, that they may, through the body, act favorably upon the mind.HBH 12.4

13. What is required in properly treating upon the care of the human body?HBH 12.5

To properly treat upon the care of the human body, it is necessary to take into view, and thoroughly investigate, the nature, conditions, and relations of man; to understand the modifying influences of the mind and morals upon the health and morbid sensibilities and sympathies of the system. Man finds himself upon the stage of life, surrounded by innumerable influences, acted upon at every point, and he is continually conscious, not only of his own existence and the action of surrounding influences, but of an unceasing desire for happiness. This desire itself is a living proof that our benevolent Creator has fitted us for happiness, not only in a future state, but here; and he has adapted everything within us and around us to answer this desire, in the fulfillment of those laws of life, health, and happiness, which He, in wisdom and in goodness, has established in the constitutional nature of things.HBH 12.6

14. What are the faculties of all living bodies?HBH 13.1

All living bodies possess those faculties by which their nourishment and growth are effected, and their temperature regulated. The little acorn placed in a genial soil, other circumstances being favorable, is excited to action by virtue of its own vitality. It puts forth its roots, twigs, branches and leaves, till it becomes a giant oak. All the vital operations of the tree are maintained till the vital property is worn out or destroyed, when its death ensues. The tree by nature is fixed to the spot from whence it sprang,-unconscious of its being, without any organs of external perception, or voluntary motion. So far as the vital operations are considered by which chyme, chyle and blood are produced, the blood circulated, the body in all its parts nourished, and its growth effected, its temperature regulated, and all the other functions of organic life sustained, man is as destitute of animal consciousness as the oak. But in man there are two classes of functions. Besides the class already mentioned, concerned in the growth and sustenance of the body, there is a secondary class, which consists of those functions which minister to the wants of the primary class. This class is established with special reference to the relation existing between those internal wants and the external supplies, and general external relations of the body. This second class of functions is peculiar to animal bodies.HBH 13.2

15. What are the powers of the vital economy?HBH 13.3

The vital economy seems to possess the power of supplying from the common and ordinary current of blood, without any known variation in the food from which it is formed, a large increase of appropriate nourishment for particular structures, and at the same time regularly sustaining the general function of nutrition in every part and substance of the system. From the same chyle various substances are produced, opposite in their qualities, and composed of essentially different elements. The flesh of the rattlesnake is eaten by many as a great luxury, and its blood may be put upon a fresh wound with perfect safety; and yet from that same blood is secreted a poison, which, if mingled with the blood of our system, will prove fatal to life in a very short time.HBH 13.4

16. What other remarkable facts are noticeable in the action of the blood of the human system?HBH 14.1

From the same atoms that enter into the formation of minerals and vegetables, the living blood is formed; by a different arrangement, in obedience to the laws of vitality in the animal system, from the matter composing this same living blood, the bone of the animal is formed; by a still different arrangement, the animal muscle is formed from the same blood; and by an arrangement still different from the others, from the matter of the same blood is formed the living animal nerve, which is the most remarkable, for its peculiar properties and powers, of any known material structure. All these are purely results of vital power, acting and accomplishing its ends as required by the body.HBH 14.2

17. What is the vital force of the human body?HBH 14.3

It is that power placed in the human body, at its birth, which will enable the body, under favorable circumstances, to live to a certain age. It is this which enables the body to rally and bring to bear its energies in throwing off disease.HBH 14.4

It also battles against those influences that are liable to produce disease. It is spoken of in common-place language as the constitution. Of one it is said, “He will rally from that disease if his constitution is not broken.” Of another, “He cannot rally, his constitution is gone;” meaning that either their vital force has so far been expended, or interfered with by violations of nature’s laws, that it no longer has power to battle for the life of the body.HBH 15.1

18. Can the original stock of this vital force be increased or diminished?HBH 15.2

It cannot be restored when once expended, but it may be wasted, and life shortened proportionately. If the life force has been measurably wasted, by placing the person in the most favorable relations to life, his days may be protracted to a much greater extent than if he were left to follow out the ordinary habits of life. A realizing sense of these facts should certainly lead us to manifest the greatest care, lest we overtax our energies, waste our life force, and shorten our days.HBH 15.3

19. How is the life of the body constantly maintained?HBH 15.4

Chemical agents, and the physical laws of nature, are constantly exerting their influence on living bodies, causing an expenditure of vital power, and tending to the destruction of the vital constitution, and the decomposition of the organized matter. Therefore, life maintains a continual conflict with opposing forces; and hence it has been with truthfulness said, “Life is a forced state-a temporary victory over the causes which induce death.”HBH 15.5

20. What peculiarity is noticeable in the temperature of the human body?HBH 16.1

The temperature of the human blood is, in a robust man, about ninety-eight degrees; and it hardly varies two degrees from this point, whether the temperature of the surrounding atmosphere be twenty degrees below zero or two hundred and sixty degrees above it. The animal body most completely resists the action of superficial heat and cold. The more vigorous the vital power is in animal bodies, the better are they enabled to sustain the extremes of heat and cold.HBH 16.2

21. What can you say of the carbonic-acid gas thrown off by the human system in its action?HBH 16.3

Carbonic-acid gas is thrown off in immense quantities by perspiration and respiration, and this, when received into the lungs, without a mixture of atmospheric air, is almost instantaneously destructive of animal life, but the vegetable economy, during the day, decomposes this gas, retains its carbon as vegetable nourishment, and sets free the oxygen, which is the peculiar principle of the atmosphere that supports animal respiration.HBH 16.4

22. What is noticeable in the formation of the animal structure?HBH 16.5

The most simple form of animalized matter composing the living body in the chyle, which is separated from the digested food in the alimentary canal, and enters the capillary tubes, by which it is conveyed to the blood vessels. This pearly-colored fluid, by chemical analysis, is almost wholly resolved into water. As it passes along the vitalizing tubes it becomes more and more albuminous and fibrinous. From the blood the vital economy of the body elaborates all the substances and forms of matter composing the animal body, constructing with marvelous skill and wisdom the blood vessels and the alimentary tube, with the assemblage of organs associated with it for the purpose of nutrition, and the outer walls of the body, with its limbs and organs of external relations. All the solid forms of the body, the bones, cartilages, ligaments, tendons, muscles, nerves, etc., are made from this fluid blood. They may all be reduced to three general kinds of substances: namely, the gelatinous, the fibrinous, and the albuminous, or, the cellular, the muscular, and the nervous tissue. The gelatinous substance, or cellular tissue, enters into the formation of the bones, cartilages, and tendons. It also forms sheaths for every muscle and for every cord of the nervous system. The fibrinous substance enters into the formation of the muscular tissue. The albuminous is the nervous tissue, which is the highest order of organized matter, and is endowed with the most peculiar and wonderful vital properties, and these properties are concerned in the functions of digestion, absorption, respiration, circulation, secretion, and organization, or the process of structure, and the production of animal heat.HBH 16.6

23. What is the only element of positive motion in the human body?HBH 17.1

With very limited exception, if any, the vital contractility of the muscular tissue is the only element of positive motion in the living animal body. Hence the muscular tissue is distributed wherever motion is required. The windpipe, stomach, intestines, heart, diaphragm, and several other internal organs are also supplied with this tissue.HBH 17.2

24. What other arrangement is made in the human body for the security and protection of the organs?HBH 18.1

The cavity of the body is divided by the muscular substance called the diaphragm, into two apartments. The upper one is called the thorax or chest, which extends from the neck to the breast-bone in front, and somewhat lower at the sides and back, and contains the lungs, heart, a portion of the large blood-vessels, and the esophagus, or food pipe. The lower division is called the abdominal cavity, and contains the liver, stomach, intestinal canal, pancreas, spleen, kidneys, etc. There is also a peculiar texture of the cellular tissue, called the serous membrane, which lines both cavities of the body, and is then extended and folded in such a manner as to envelop each organ separately, holding them in a measure in their proper place. This serous membrane in the upper portion of the body is called the pleura. It encloses each lung separately, and by two sheets, extending from the breast to the back, forms a double partition between the lungs. These two sheets are separated at the lower part of the chest to receive the heart. In a healthy state of the body the serous membrane has no animal sensibility. In fleshy people large quantities of fat are accumulated in many parts of this tissue. In a healthy action of all parts of the system, excess of fat never occurs, but waste and supply are equal. It must, from the considerations introduced in this chapter, be a matter of interest to all, to contemplate the subject of the following chapters, to learn what tends to waste our bodily structures, what habits of living will restore their proper action, and how we may thrive in mind and body.HBH 18.2