CHAPTER II 



THE MUSCLES 



The Muscles Flexion and Extension The Tendons Contraction 

 Physical Strength Necessity for Exercise Its Effects Forms of 

 Exercise Walking Riding Gymnastics Open-air Exercise 

 Effects of Exercise Excessive Exercise Sleep Recreation 



1. The Muscles. The great mass of the body external to 

 the skeleton is composed of the flesh, or Muscles, which largely 

 determines its outline and weight. The muscles are the organs 

 of motion. Their number is about four hundred, and to each 

 of them is assigned. a separate and distinct office. They have 

 all been studied, one by one, and a name given to each, by the 

 anatomist. Each is attached to bones which it is designed to 

 move. A few are circular in form, and enclose cavities, the 

 size of which they diminish by contraction. 



2. If we examine a piece of flesh, we observe that it is soft, 

 and of a deep red color. Its structure appears to be composed 

 of layers and bundles of 



small fibres. Let us fur- a 

 ther examine these fibres 

 under the microscope. 

 We discover that these 

 in turn are made up of 

 still finer fibres, or fibril- 

 Ice, as shown in Fig. 12. 

 The fibres are beauti- 

 fully marked by parallel 

 wavy lines, about ten 

 thousand to an inch, 



FIG. 12. MUSCULAR TISSUE 



a, &, Striped muscular fibres ; c, The same more 



highly magnified 



1. What are the muscles? Their number? The design of most of them ? Of a few? 



2. The structure of flesh? Its color, etc. ? The composition of the fibres ? How marked? 



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