460 THE NERVOUS SYSTEM. 



network of inosculating bundles, in the substance of the Gasserian 

 ganglion. This ganglion forms a flattened, crescentic mass of gray sub- 

 stance, mingled with the fibres from the sensitive root. The ganglionic 

 cells are unipolar *in form, giving off fibres in a peripheral direction, 

 which, according to Key and Betzius, unite with those of cerebral origin 



FIG. 123. 



DIAGRAM OP THE FIFTH NERVE AND ITS DISTRIBUTION. 1. Sensitive root. 2. Motor root. 3 Gas- 

 enan ganglion. I. Ophthalmic division. II. Superior maxillary division. III. Inferior maxillary 

 division. 4. Supra-orbital nerve, distributed to the skin of the forehead, inner angle of the eye 

 d root of the nose. 5. Infra-orbital nerve; to the skin of the lower eyelid side of the nose' 

 and skin and mucous membrane of the upper lip. 6. Mental nerve; to the integument of the 

 cnm and edge of the lower jaw, and skin and mucous membrane of the lower lip. n n External 

 terminations of the nasal branch of the ophthalmic division; to the mucous membrane of tlie 

 inner part of the eye and the nasal passages, and to the base, tip, and wing of the nose * Tem- 

 poral branch of the superior maxillary division ; to the skin of the temporal region 'm 'Malar 

 nch of the superior maxillary division ; to the skin of the cheek and neighboring parts. 6. Buccal 

 " ' maxillary division ; P assi "g al g ^e surface of the buccinator muscle, 



aclU h i e uccnaor musce, 



and d tributed to the mucous membrane of the cheek, and to the mucous membrane and skin 

 the i Lingual nerve ; to the mucous membrane of the anterior two-thirds of the tongue. 



' P< l " 



- . 



the'eTt T P< l ?", Ch f the hlferi0r maxilla T ^vision ; to the skin of the anterior part 

 asseter I T ?* T "?*"** '^^ regi n ' * ** Musc lar "ranches; to the temporal, 

 M>M-t , , , and internal and external ptorygold muscles, y. Muscular branch ; to the mvlo-hyoid 

 nor belly oi the diagastric. /. Sensitive branch of communication to the facial ner^. 



in the sensitive root. The motor root passes beneath the ganglion 

 stmct bundle, neither giving nor receiving any communicating 

 Sbres. At the anterior border of the ganglion, the nerve separates 

 into its three bundles, namely, the first, or ophthalmic; the second, 



