INTRODUCTION. 3 



self-winding, self-regulating, self-repairing, self-directing, 

 amazes us. 



Hygiene. We take up the study of the human body 

 mainly that we may learn how to preserve health ; the 

 science of health is hygiene. 



Physiology. In order to keep the various organs in 

 good order we must know what their natural work is, and 

 how they do it ; the science of the action of the body and 

 its parts is physiology. 



Organ. Any part, or member, of the body, which has 

 a special work to do, is called an organ, as the hand, the 

 eye, or the stomach. 



Function. -- The work, or action, of each organ is 

 its function. 



Anatomy. In order to understand the working of 

 each organ it is usually necessary to know something 

 of its construction ; the science of structure is anatomy. 

 We do not need to go far into anatomy to obtain a fail- 

 knowledge of the manner in which our organs do their 

 work. The surgeon, of course, must be able to locate 

 accurately the various blood tubes, nerves, muscles, etc. 

 We need to know only the general structure of the body 

 and, more in detail, some of the more important organs, 

 such as the heart, the lungs, the larynx, the eye, etc. 

 It is fortunate for us that these organs in the sheep, pig, 

 and cow are so nearly like our own that they serve 

 admirably to enable us to understand ourselves. 



Tissues. Every organ is composed of several different 

 kinds of material. For instance, in a slice across a ham 

 we see the skin on the outside, then fat, lean, and bone. 



