CHAPTER III 

 THE MUSCLES AND HOW TO USE THEM 



64. Muscles as the Organs of Motion. The energy set 

 free in the burning, or oxidation, which is constantly going 

 on in the bodily tissues is the source of the active powers 

 of our bodies. 



These active powers are mainly manifested in the form 

 of motion or movement, either of a part of the body or of 

 the body as a whole. 



These total or partial bodily movements are produced by 

 muscles, the organs of motion. 



65. Variety of Muscular Action. The lean meat or flesh 

 which forms the rounded, shapely covering for our bony 

 framework is muscle. When we eat beefsteak or mutton 

 we are eating muscle. Muscles, of which there are more 

 than four hundred in the body, are also the means by 

 which the body is kept in the erect position and in other 

 positions which call for effort. 



The limbs are moved by muscles. Even the motions of 

 the stomach and the action of the heart are caused by 

 muscles. Muscles move the skin. In many animals this 

 action is well marked, as when the horse shakes his hide 

 to get rid of biting flies. Muscles move the bones, the 

 lips, and the eye. 



In brief, all motion in our bodies is dependent upon muscular 

 activity. 



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