THE FIFTH PAIE. 



533 



summit of the petrous part of the temporal bone. Here the larger root 

 alters in appearance : its bundles of fibres diverge and enter the Gas- 

 serian ganglion. The fasciculi divide and unite in tlie expanded part 

 of the nerve, so as to form a plexiform network. The smaller root 

 passes inside and beneath the ganglion, without its nerve-fibres being 

 incorporated in any way with it, and joins outside the skull the lowest 

 of the three trunks which issue from the ganglion. 



Fig. 335.— General Plan Fig. 335. 



OP THE Branches op 

 THE Fifth Pair (after 

 a sketcli by Charles 

 Bell), i 



1, lesser root of the 

 fifth pair ; 2, greater 

 root passing for\yards 

 into the Gasserian gang- 

 lion ; 3, placed on the 

 bone above the ophthal- 

 mic nerve, which is seen 

 dividing into the supra- 

 orbital, lachrjinal, and 

 nasal branches, the latter 

 connected with the o^ih 

 thalmic ganglion ; 4, 

 jjlaced on the bone close 

 to the foramen rotundum, 

 marks the superior max- 

 illary division, which is 

 connected below with the 

 spheno-palatine ganglion, 

 and passes forwai-ds to 

 the infraorbital foramen ; 

 5, placed on the bone over 

 the foramen ovale, marks 

 the submaxillary nerve, 

 giving otf the anterior auri- 

 cular and muscular bran- 

 ches, and continued by the 

 inferior dental to the lower 

 jaw, and by the gustatory 



to the tongue ; a, the submaxillary gland, the submaxillary ganglipn placed above it in 

 connection with the gustatory nerve ; 6, the chorda tympani ; 7, the facial nerve issuing 

 from the stylo-mastoid foramen. 



The ganglion of the fifth nerve or Gasserian ganglion (ganglion semi- 

 lunare), occupies a depression on the upper part of the petrous portion 

 of the temporal bone, near the apex, and is somewhat crescentic in 

 form, the convexity being turned forwards. It is flattened and striated 

 on the surface. On its inner side the ganglion is joined by filaments 

 from the carotid plexus of the sympathetic nerve, and, according to 

 some anatomists, it furnishes from its back part filaments to the dura 

 mater. 



Distribution. — From the fore part, or convex border of the Gas- 

 serian ganglion, proceed the three large divisions of the nerve. The 

 highest (first or ophthalmic trunk) enters the orbit ; the second, the 

 upper maxillary nerve, is continued forwards to the face, below the 

 orbit ; and the third, the lower maxillary nerve, is distributed chiefly to 

 the external ear, the tongue, the lower teeth, and the muscles of masti- 

 cation. The first two trunks proceed exclusively from the ganglion 



