266 



MUSCLES 



classification arises from the fact that some muscles are 

 both voluntary and involuntary, for example, the muscles 

 that close the eyelids. 



Furthermore dissection has shown that all muscle 

 tissue in one body may be put into one of three classes, 



Fig. 113 — Biceps muscle. 



each with a distinct structural formation and it is this 

 structural classification we shall adopt. These three classes 

 are known as striated, non-striated, and heart muscle. 



These three kinds of muscle tissue combined constitute 

 nearly half of the entire weight of the body, and in their 

 action is consumefl the greater part of the food and oxygen 

 supply of the body. 



