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THE HORSE IN HEALTH AND DISEASE 



certain portions of the nasal cavity and has to do with the special 

 sense of smell. 



The second or optic nerve furnishes the eyes and has to do with 

 the special sense of sight. 



The third or oculomotor nerve supplies all except two of the 

 muscles of the eyeball with motor power. 



Fig. 41. — Cross-section of spinal cord: 1, Dorsal column; 2, lateral column; 

 3, ventral column; 4, dorsal horn; 5, ventral horn; 6, 7, commissures; 8, central 

 canal; 9, dorsal septum; 10, ventral fissure; 11, dorsal nerve-root; 12, ventral 

 nerve-root; 13, spinal ganglion; 14, spinal nerve; 15, intervertebral foramen; 

 16, arch of vertebra; 17, epidural space; 18, dura mater; 19, ligament; 20, 20, 

 venous sinuses; 21, spinal artery; 22, body of vertebra. The outer part of the 

 arachnoid and pia mater are not shown. (Sisson, Anatomy of Domestic 

 Animals.) 



The fourth or trochlear nerve is the smallest of the cranial nerves. 

 It ends in the posterior parts of the superior oblique muscle of the 

 eyeball. 



The fifth or trifacial nerve is the largest of the series. It has 

 both motor and sensory fibers for different parts of the face and 

 mouth and has a very important function to perform. 



The sixth or abducent nerve supplies the retractor muscles of the 

 eyeball. 



The seventh or facial nerve is responsible for the movements of 



