552 



THE NERVOUS SYSTEM 



are in the Gasserian ganglion. The nerve appears at the ventral surface of 

 the pons near its front edge, at some distance from the mid-line. 



Motor Functions. The first and second divisions of the nerve, which arise 

 wholly from the larger root, are purely sensory. The third division is joined 

 by the motor root of the nerve and is of course both motor and sensory. 



Motor branches of the lesser or non-ganglionic portion of the fifth supply 

 the muscles of mastication, namely, the temporal, masseter, two pterygoid, 

 anterior part of the digastric, and mylohyoid. Filaments are also said to supply 



FIG. 386. General Plan of the Branches of the Fifth. X J. i, Lesser root of the fifth; 2, greater 

 root passing forward into the Gasserian ganglion; 3 , placed on the bone above the ophthalmic nerve, 

 which is seen dividing into the supra-orbital, lachrymal, and nasal branches, the latter connected 

 with the ophthalmic ganglion; 4, placed on the bone close to the foramen rotundum, marks the 

 superior maxillary division, which is connected below with the spheno-palatine ganglion, and 

 passes forward to the infra-orbital foramen; 5, placed on the bone over the foramen ovale, marks 

 the inferior maxillary nerve, giving off the anterior auricular and muscular Branches, and continued 

 by the inferior dental to the lower jaw, and by the gustatory to the tongue; a, the submaxillary 

 gland, the submaxillary ganglion placed above it in connection with the gustatory nerve; 6, the 

 chorda tympani; 7, the facial nerve issuing from the stylomastoid foramen. (Charles Bell.) 



the tensor tympani and tensor palati (Kolliker). The motor function of these 

 branches is proved by the violent contraction of all the muscles of mastication 

 in experimental irritation of the third or inferior maxillary division of the fifth 

 nerve; by paralysis of the same muscles when the nerve is divided or dis- 

 organized; and by the retention of the power of these muscles when the 

 facial nerve is paralyzed. Whether the branch of the fifth nerve which is 

 supplied to the buccinator muscle is entirely sensory, or in part motor also, 

 must remain for the present doubtful. From the fact that this muscle, besides 



