616 



NERVOUS SYSTEM. 



ventricle. Here they lose their white color, become gray, and present numerous globules 

 of gray substance between their filaments. 



From the origin above described, the small root passes beneath the ganglion of Gasser 



from which it sometimes, though not constantly, receives a filament of communication 



lies behind the inferior maxillary branch of the large root, and passes out of the cranial 

 cavity by the foramen ovale. Within the cranium, the two roots are distinct ; but, after 

 the small root passes through the foramen, it is united by a mutual interlacement of 

 fibres with the sensitive branch. 



The course of the motor root of the fifth possesses little physiological interest. It is 

 sufficient in this connection to note that the inferior maxillary nerve, made up of the 

 motor root and the inferior maxillary branch of the sensitive root, just after it passes out 



FIG.- 199. Distribution of the small root of the fifth nerve. (Ilirschfeld.) 



1, branch to the masseter muscle; 2, filament of this branch to the temporal muscle; 3, buccal 'branch ; 4, 

 branches anastomosing with the facial nerve ; * filament from, the buccal branch to the temporal muscle; 

 6, branches to the external pterygoid muscle ; 7, middle deep temporal branch ; 8, auriculo-temporal nerve ; 

 9, temporal branches; 10, auricular branches; 11, anastomosis with the facial nerve; 12, lingual branch; 

 13, branch of the small root to the mylo-hymd muscle ; 14, inferior dental nerve, with its branches (15, 15); 16, 

 mental branch ; 17, anastomosis of this branch with the facial nerve. 



by the foramen ovale, divides into two branches, anterior and posterior. The anterior 

 branch, which is the smaller, is composed almost entirely of motor filaments and is distrib- 

 uted to the muscles of mastication. It gives off five branches. The first of these passes 

 to be distributed to the masseter muscle, in its course occasionally giving off a small 

 branch to the temporal muscle and a filament to the articulation of the inferior maxilla 

 with the temporal bone. The two deep temporal branches are distributed to the tem- 

 poral muscle. The buccal branch sends filaments to the external pterygoid and to the tem- 

 poral muscle, and a small branch is distributed to the internal pterygoid muscle. From the 

 posterior branch, which is chiefly sensitive but contains some motor filaments, branches 



