CHAPTER XVII 



MUSCLES 



328. Use of muscles. The bony framework of the body 

 is covered and rounded out by muscles. Muscles form 

 one half of our weight. They are the servants of the 

 mind, and do its physical work, while the brain does its 



mental work. If the brain and 

 muscles did not wear out, there 

 would be no need of a stomach. 



As it is, the stomach, heart, 

 lungs, and other parts are needed 

 to feed and to keep the muscles 

 and brain alive and well. 



Muslie cells, cut across 329. Structure of muscles. 

 (X2oo). Lean meat is mostly muscle. A 



a muscle cell. muscle is large at one end or in 



b connective tissue binding the & 



cells together. the middle, and is fast to a bone. 



Its other end generally grows 



smaller and is prolonged in a strong cord called a tendon. 

 The tendon crosses a joint and is fast to another bone. 



Each muscular bundle is made of cells like strings. 

 These are the largest cells in the body, but they cannot 

 be seen without a microscope. They are bound in small 

 bundles by delicate strings of connective tissue. These 

 bundles are bound into a large bundle which we call a 

 muscle. Each large bundle of muscle is covered with a 

 thick woven skin of connective tissue. Finally, all the 



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