414 



PRACTICAL ANATOMY. 



as follows : (i) The fifth nerve supplies with sensation all the teeth. (2) The fifth 

 nerve supplies with sensation the gums, by little nerves called the nervi gingivales. 

 (3) The fifth nerve supplies the sides of the tongue, and the anterior one-half of 

 the same through its lingual or gustatory branch. (4) The fifth nerve supplies 

 the muscles of mastication with motion muscles whose function is to move the 

 mandible. (5) The fifth nerve supplies the temporo-mandibular articulation, be- 

 cause the muscles it supplies move this articulation. The same branch that sup- 

 plies the articulation, the auriculo-temporal, also supplies the drum of the ear 

 and the auditory canal, because these parts are secondary in the acquisition of 

 food. (6) The fifth nerve supplies the skin covering the fullest region of the 



. 290. FIFTH CRANIAL NERVE. 



muscles of mastication ; in round numbers, the cutaneous region in front of a line 

 passing from side to side through the auditory meatuses is supplied by the auri- 

 culo-temporal, supraorbital, infraorbital, and mental branches of this nerve. (7) 

 The fifth nerve supplies the anterior belly of the digastric muscle and the mylo- 

 hyoid muscle, but these muscles are depressors of the mandible. (8) The fifth 

 nerve has numerous connections with the facial nerve. Study the facial and 

 temporal relations between these two nerves ; the chorda tympani ; the otic, sub- 

 maxillary, and Meckel's ganglia. The trifacial nerve supplies the muscles of 

 mastication with motion, and the skin covering these muscles. 



1 I 'liat can you say of the sixth cranial nerve / 



This nerve is distributed solely to the external rectus muscle. It arises from 



