CHAPTER XXXIX 

 MUSCLES 



662. Movements within the body. Every action of the 

 body has motion for its basis, and every cell possesses 

 motion of some form. But certain cells of the body are 

 set apart to produce motion in the various liquids of the 

 body and to move different parts of the body itself. Cells 

 whose work is to produce motion are called muscle cells. 



663. Involuntary muscles. Some movements of the 

 body go on wholly without our knowledge and are not 

 affected by the will. Such are the movements of the 

 blood, and of the peristalsis of the intestine. These invol- 

 untary movements are produced by muscle cells which are 

 governed by the sympathetic nervous system. Each mus- 

 cle cell resembles a string with pointed ends. They are 

 wrapped around the arteries, intestine, bronchi, 



and other hollow organs. They are inter- 

 woven with the other tissues of the organ and 

 cannot be recognized without a microscope. 



664. Voluntary muscles. The muscles which 

 enable the body to move are under control of 

 the will. They are situated mostly upon the 

 outside of the bones, and altogether form over 



one half of the weight of the body. They A muscle cell 

 round out the figure and impart to it strength (x 4 o)< 

 and beauty. The other organs of the body of man exist in 

 order that the brain and muscles may subsist and work 

 out the plans of man's higher nature. 



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