538 



TEXT-BOOK OF PHYSIOLOGY. 



ophthalmic, the superior maxillary, and the inferior^ maxillary. 

 Branches of the carotid plexus of the sympathetic enter the nerve 

 in the neighborhood of the ganglion of Gasser and accompany its 

 branches. % 



Distribution. i. The Central Branches. The axons of the 

 large root pass backward intojLhe^jxms Varolii on its lateral aspect. 

 After entering the pons each axon divides into two branches, one 

 of which passes upward a short distance, the other passes down- 

 ward, descending as far as the second cervical segment. Both 

 branches give off a number of collaterals, each of which terminates 

 in fine end-tufts around nerve-cells in the substantia gelatinosa. 



2. The Peripheral Branches. 

 The peripheral axons emerge 

 from the peripheral end of the 

 ganglion of Gasser in three dis- 

 tinct and separate branches, 

 each of which is distributed to a 

 different region of the face and 

 head. 



i. The ophthalmic branch passes 

 forward and subdivides 

 into three large branches, 

 the frontal, the lachrymal, 

 and the nasal. The ulti- 

 mate termmation of the 

 branches of these nerves 

 is as follows: viz., the con- 

 juftctiva and skin^of ~trle 

 upper ~ey elid, the cornea, 

 the skin of the forehead 

 and the nose, the lachrymal 

 gland and caruncle, and 

 the mucous membrane of 

 the nose (Fig. 248). 



The superior maxillary branch passes forward through the fora- 

 men rotundum, crosses the spheno-maxillary fossa, enters the 

 infra-orbital canal, and emerges at the infra-orbital foramen. In 

 its course it gives off a number of branches which are distributed 

 as follows: viz., to the integument and co : njiLacJjya of the Jqwjiu 

 lid, the nos^e, chgek, and upper Jip, the palate, the teeth of the 

 upper jaw, and the alveolar processes (Fig. 249). 

 The inferior maxillary branch passes through the foramen ovale, 

 after which it subdivides into three branches the auriculo^;em- 

 poral, the lingual, and the inferior dental. The ultimate 

 branches are distributed as follows: viz., the external auditory 



FIG. 248. OPHTHALMIC BRANCH OF THE 

 FIFTH, i. Ganglion of Gasser. 2. 

 Ophthalmic division of the fifth. 3. 

 Lachrymal branch. 4. Frontal branch. 

 5. External frontal. 6. Internal frontal. 

 7. Supra -trochlear. 

 9. External nasal. 

 (Hirschfeld.} 



8. Nasal branch. 

 10. Internal nasal. 



