654 THE NERVOUS SYSTEM 



sensory fibers, however, can be traced down in the medulla oblongata as far 

 as the upper part of the cord. The motor nucleus stretches forward as far 

 as the superior corpus quadrigemirium, giving rise to a bundle of long fibers 

 termed the descending root. The sensory nucleus receives a tract of sensory 

 fibers from the trigeminus extending as low as the second cervical nerve, 

 and this forms a tract at the tip of the posterior cornu, between it and the 

 restiform body. The cells of origin of the sensory tract are in the Gas- 



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.) 



serian 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 



