678 



DISSECTION OF THE HEAD. 



turn nasi 



pterygo- 

 palatine 

 branch ; 



Vidian 

 branch. 



nasal The nasal or spheno-palatine artery enters the nose through the 



branches, spheno-palatine foramen, and divides into branches. Some of these 

 (lateral nasal) are distributed on the spongy bones, and the outer 

 wall of the nasal fossa, and supply offsets to the posterior ethmoidal 

 one to sep- cells. One long branch, naso-palatine or artery of the septum nasi, 

 runs on the partition between the nasal fossae' to the incisor foramen, 

 through which it anastomoses with the descending palatine in the roof 

 of the mouth ; this branch accompanies the naso-palatine nerve, and 

 covers the septum with numerous ramifications. 



The pterygo-palatine is a very small branch which, passing 

 backwards through the canal of the same name, is distributed 



to the lining membrane of 

 the pharynx. 



The Vidian or pterygoid 

 Iranch is contained in the 

 Vidian canal with the nerve 

 of the same name, and ends 

 on the mucous membrane of 

 the Eustachian tube and the 

 upper part of the pharynx. 



Some small nasal arteries 

 are furnished to the roof of 

 the nasal fossa by the pos- 

 terior ethmoidal branch of the 

 ophthalmic (pp. 647, 648). 

 Also the anterior ethmoidal 

 (internal nasal) enters the 

 cavity with the nasal nerve, 

 and ramifies in the lining 

 membrane of the fore part 

 of the nasal chamber as low 

 as the vestibule ; a branch 

 passes to the face between 

 the nasal bone and the carti- 

 lage with the nerve. Other 

 offsets from the facial artery 

 supply the nose near the 

 nostril. 



Veins. The veins accompanying the terminal branches of the 

 internal maxillary artery enter the alveolar plexus in the spheno- 

 maxillary fossa. Beneath the mucous membrane of the nose the 

 veins have aplexiform arrangement, as before said. 



FACIAL NERVE IN THE TEMPORAL BONE (fig. 240). This nerve 

 winds through the petrous part of the temporal bone ; and it is 

 followed with difficulty in consequence of the extreme density of 

 the bone, and the absence of marks on the surface to indicate its 

 position. To render this dissection easier, the student should be 

 provided, for comparison, with a temporal bone, in which the course 

 of the facial nerve and the cavity of the tympanum are displayed. 



FIG. 240. FACIAL NERVE IN THE 

 TEMPORAL BONE. 



1. Facial nerve. 



2. Large superficial petrosal. 



3. Small superficial petrosal from 

 Jacobson's nerve. 



4. External superficial petrosal. 



5. Chorda tympani of the facial. 



Veins to 

 alveolar 

 plexus. 



Facial 

 nerve. 



