TEIFACIAL NERVE. 187 



mucous membrane of the frontal sinus, and the pericranium 

 covering the frontal and 'parietal bones. 



The nasal branch, before it penetrates the orbit, gives off 

 a long, delicate filament to the ophthalmic ganglion, consti- 

 tuting its sensory root. It then gives off the long ciliary 

 nerves, which pass to the ciliary muscle and iris. Its trunk 

 then divides into the external nasal, or infra-trochlearis, and 

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

 tributed 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-maxillary fossa, the 

 first branch is the orbital, which passes into the orbit, giving 

 off one branch, the temporal, which passes through the tem- 

 poral fossa by a foramen in the malar bone, and is distrib- 

 uted 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 in- 

 tegument over this bone. In the spheno-maxillary fossa, 

 are also given off two branches, which pass to the spheno- 

 palatine, or Heckel'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 corresponding alveolar processes, 

 and to the antrum. 



In the infra-orbital canal, a large branch, the anterior 

 dental, is given off to the teeth and mucous membrane of the 

 alveolar processes not supplied by the posterior dental nerves. 

 This nerve anastomoses with the posterior dental. 



The terminal branches upon the face are distributed to 



