CHAPTER XIII 



GENERAL DISEASES OF THE LOCOMOTORY APPARATUS 



General Discussion. — The movements of the different parts 

 of the animal body depend on the nnion of the bones that form 

 the skeleton (Fig. 2S), and mode of insertion of the muscles. 

 The bones meet and form joints or articulations. These are 



Fig. 28. — Skeleton of horse. 



divided into three clases: movable, mixed and immovable. 

 Nearly all of the articulations in the extremities belong to the 

 movable class. The articulations between the bodies of the 

 vertebrffi belong to the mixed, and those between the flat bones 

 of the head to the immovable class. 



The bony surfaces that meet and form the different types of 

 articulations are held together by ligaments (Fig. 20). Some- 



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