Chapter II
THE HUMAN BODY
The world is compounded of the five elements,—earth, water, air, fire, and ether. So too is our body. It is a sort of miniature world. Hence the body stands in need of all the elements in due proportion,—pure earth, pure water, pure fire or sunlight, pure air, and open space. When any one of these falls short of its due proportion, illness is caused in the body.
The body is made up of skin and bone, as well as flesh and blood. The bones constitute the frame-work of the body; but for them we could not stand erect and move about. They protect the softer parts of the body. Thus the skull gives protection to the brain, while the ribs protect the heart and the lungs. Doctors have counted 238 bones in the human body. The outside of the bones is hard, but the inside is soft and hollow. Where there is a joint between two bones, there is a coating of marrow, which may be regarded as a soft bone. The teeth, too, are to be counted among the bones.
When we feel the flesh at some points, we find it to be tough and elastic. This part of the flesh is known as the muscle. It is the muscles that enable us to fold and unfold our arms, to move our jaws, and to close our eyes. It is by means of the muscles, again, that our organs of perception do their work.
It is beyond the province of this book to give a detailed account of the structure of the body; nor has the present writer enough knowledge to give such an account. We will, therefore, content our-selves with just as much information as is essential for our present purpose.
The most important portion of the body is the stomach. If the stomach ceases to work even for a single moment, the whole body would collapse. The work of the stomach is to digest the food, and so to provide nourishment to the body. Its relation to the body is the same as that of the steam engine to the Railway train. The gastric juice which is produced in the stomach helps the assimilation of nutritious elements in the food, the refuse being sent out by way of the intestines in the form of urine and fæces. On the left side of the abdominal cavity is the spleen, while to the right of the stomach is the liver, whose function is the purification of the blood and the secretion of the bile, which is so useful for digestion.
In the hollow space enclosed by the ribs are situated the heart and the lungs. The heart is between the two lungs, but more to the left than the right. There are, on the whole 24, bones in the chest; the action of the heart can be felt between the fifth and the sixth rib. The lungs are connected with the windpipe. The air which we inhale is taken into the lungs through the windpipe, and the blood is purified by it. It is of the utmost importance to breathe through the nose instead of through the mouth.
On the circulation of the blood depend all activities of the body. It is the blood that provides nourishment to the body. It extracts the nutritious elements out of the food, and ejects the refuse through the intestines, and so keeps the body warm. The blood is incessantly circulating all over the body, along the veins and the arteries. The beatings of the pulse are due to the circulation of the blood. The pulse of a normal adult man beats some 75 times a minute. The pulses of children beat faster, while those of old men are slower.
The chief agency for keeping the blood pure is the air. When the blood returns to the lungs after one complete round over the body, it is impure and contains poisonous elements. The oxygen of the air which we inhale purifies this blood and is assimilated into it, while the nitrogen absorbs the poisonous matter and is breathed out. This process goes on incessantly. As the air has a very important function to perform in the body, we shall devote a separate chapter to a detailed consideration of the same.