104 



PARTICULAR FRACTURES. 



lower jaw, or the inferior maxillary division of the fifth nerve 

 may be injured and pressed open by a piece of depressed bone, 

 causing excruciating pain, and even fatal results, if not at once 

 removed. 



FRACTURES OF THE CRANIAL BONES. 



By the arrangement of the cranial bones, an ovate box is 

 formed, which resists external violence after the manner of an 

 arch ; yet it ia sometimes fractured by the direct application 



of force to the fractured parts, but 

 more frequently — in tlie lower ani- 

 mals, especially in the horse — at a 

 part of the skull distant from the 

 J)lace where the violence has been 

 received. This is called " indirect 

 fracture," or fracture hy count er- 

 stroht, or what is termed by the' 

 French, /vac/w re par contre-ccnip. 



Fractures of the base of tlie skull' 

 are, in all instances, caused by the' 

 indirect applieation of violence, and' 

 this is easily explained. If a horse' 

 fall, or be struck heavily by a blunt 

 instiTiment or obtuse body, upon the 

 occipital crest, the force thus applied 

 is resisted by the strength and tliick- 

 ness of this part of the bone, and the 

 shock is conveyed to the basilar 

 process, this being its weakest part. 

 In all cases this form of fracture 



Fio. 11.— Indirect coniminated Jg necessarily fatal 

 fracture of basilar process of ocoi- . , , /• .1 ' 



pitai and sphenoidal bones, from bomctimes the Violence 01 the 

 falling on occipitel crest a, Occi- f^U or blow is sufficient to produce 



^itaL 6, Sphenoid. , . , . . 



fracture of the part to which it is 

 applied, and also to extend to the base of the cranium. 



The fractures of the cranium may be conveniently arranged 

 as follows : — * 



\st. Simple fissure or fracture without depression. 



2d. Simple fractures with depression. 



