7. If we want to know all about a machine and how it works, we must study all its different parts and learn how they are put together, and what each part does. Then, if we want the machine to work well and to last a long time, we must know how to use it and how to take proper care of it. Do you think your watch would keep the time well if you should neglect to wind it, or if you should break any of its wheels?
8. It is just the same with the human machine which we call the body. We must learn its parts, and what they are for, how they are made, how they are put together, and how they work. Then we must learn how to take proper care of the body, so that its parts will be able to work well and last a long time.
9. Each part of the body which is made to do some special kind of work is called an organ. The eye, the ear, the nose, a hand, an arm, any part of the body that does something, is an organ.
10. The study of the various parts of the body and how they are put together is anatomy (a-nat´-o-my). The study of what each part of the body does is physiology (phys-i-ol´-o-gy). The study of how to take care of the body is hygiene (hy´-jeen).
SUMMARY.
1. The body is something like a house. It has an outside and an inside; it has hollow places inside of it, and there are many wonderful things in them.
2. The body is also like a wonderful machine.
3. It is necessary to take good care of the body in order to keep it well and useful, just as we would take good care of a machine to keep it from wearing out too soon.
4. The body has many different parts, called organs, each of which has some particular work to do.
5. In learning about the body, we have to study anatomy, physiology, and hygiene.