614 



THE NERVOUS SYSTEM 



and head, with the exception of the skin of the parotid region, acquire com- 

 mon sensibility through branches of the ganglionic division of the fifth nerve. 

 The muscles of the face and lower jaw acquire muscular sensibility through 

 the filaments of the ganglionic portion of the fifth nerve distributed to them 

 with their proper motor nerves. 



Through its ciliary branches and the branch which forms the long root 

 of the ciliary or ophthalmic ganglion, it exercises some influence on the 



FIG. 411. General Plan of the Branches of the Fifth. X ^. 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 sub- 

 maxillary 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.) 



movements of the iris. When the trunk of the ophthalmic portion is divided, 

 the pupil becomes, according to Valentine, contracted in men and rabbits, and 

 dilated in cats and dogs, but in all cases becomes immovable even under all 

 the varieties of the stimulus of light. How the fifth nerve affects the iris is 

 unexplained; it has been suggested the influence of the fifth nerve on the 

 movements of the iris may be ascribed to the affection of vision in conse- 

 quence of the disturbed circulation or nutrition in the retina. 



