TRIFACIAL, OK TRIGEMINAL NERVE. 



637 



nerves, which pass to the ciliary muscle and iris. Its trunk finally divides into the external 

 nasal, or infra-trochlearis, and the internal nasal, or ethmoidal. The infra-trochlearis is 

 distributed to the integument of the forehead and nose, to the internal surface of the 

 lower eyelid, the lachrymal sac, and the caruncula. The internal nasal is distributed to 

 the mucous membrane, and also in part to the integument of the nose. 



The superior maxillary branch of the fifth passes out of the cranial cavity by the 

 foramen rotundum, traverses the infra-orbital canal, and emerges upon the face by the 

 infra-orbital foramen. Branches from this nerve are given off in the spheno-maxillary 

 fossa and the infra-orbital canal, before it emerges upon the face. In the spheno-maxil- 

 lary fossa, the first branch is the orbital, which passes into the orbit, giving off one 

 branch, the temporal, which passes through the temporal fossa by a foramen in the malar 

 bone and is distributed to the integument on the temple and the side of the forehead. 

 Another branch, the malar, which likewise emerges by a foramen in the malar bone, is 

 distributed to the integument over this bone. In the spheno-maxillary fossa, are also 

 given off two branches, which pass to the spheno-palatine, or Meckel's ganglion. From 

 this portion of the nerve, branches are given off, the two posterior dental nerves, which 

 are distributed to the molar and bicuspid teeth, the mucous membrane of the correspond- 

 ing alveolar processes, and to the antrum. 



FIG. 214. Inferior maxillary d! vision of the fifth . (\\ irschfeld.) 



1, branch from the motor root to the niasseter muscle ; 2, filaments from this branch to the temporal muscle ; 8. Iniccal 

 brunch; 5. ti, 7. branches to the muscles; 8, auriculo-temjmral HOT? ; i, temporal branches; 10, auricular 

 branch,*; 11, a/iaxfoHni*;* n-jfh the facial nerve; 12, linrma? branch ; 1*. l>r:mcli of the motor root to the 

 mylo-hyoid nm-de; 14. l.\ in. inferior dental nerve, witii 'its branches; 16, mental branch; 17, anastomosis 

 (f this branch icith tJie facial nerve. 



In the infra-orbital canal, a large branch, the anterior dental, is given off to the teeth 

 and raucous membrane of the alveolar processes not supplied by the posterior dental 

 nerves. This nerve anastomoses with the posterior dental. 



