4 THE HUMAN BODY. 



The branch of anatomy which deals with the charac- 

 ters of the materials used in the construction of the parts 

 of the body is called histology, or, since it is mainly carried 

 on with the aid of the microscope, microscopic anatomy. 



Tissues. Each of the different primary building ma- 

 terials which can be distinguished, either with or without 

 the microscope, as entering into the construction of the 

 body, is called a tissue ; we speak, for example, of muscu- 

 lar tissue, fatty tissue, bony tissue, cartilaginous tissue, 



i f/hv*'* ^ 



and so forth ; each tissue has certain properties in which 

 it differs from all the rest, and which it preserves in what- 

 ever part of the body it may be found. It also is charac- 

 terized by certain appearances when examined with a mi- 

 croscope, which are the same for the same tissue no matter 

 where it is found. The total number of important tissues 

 is not great ; the variety in structure and use which we 

 find in the parts of the body depends mainly on the 

 diverse ways in which the same tissues are combined 

 together, over and over again, in different parts. 



Organs. A portion of the body composed of several 

 tissues, and specially fitted for the performance of a par- 

 ticular duty or function, is called an organ ; thus, the hand 

 is an organ of prehension ; the eye, the organ of sight ; 

 the stomach, an organ of digestion ; and so forth. 



Summary. The human body is made up of a limited 

 number of tissues ;* each tissue has a characteristic ap- 



What is histology? Give another name for it. 



What is a tissue? Give examples. How do tissues differ? Are 

 there a large number of important lissues? How is the variety in 

 Structure of the parts of the body produced? 



What is an organ? Give examples. Of what is the body made 

 up ? 



* The various tissues of the body will be considered in more detail subsequently.- 

 the more important re j. Bony tissue, 2. Cartilaginous tissue. 3. White fibrous 



