SPHENO-PALATINE GANGLION. 



553 



The posterior or small palatine nerve descends with a small artery through 

 the small posterior palatine canal, emerging by a separate opening behind the 

 posterior palatine foramen. It supplies the Levator palati and Azygos uvulae 

 muscles, the soft palate, tonsil, and uvula. 



The Internal branches are distributed to the septum, and outer wall of the nasal 

 fossae. They are the superior nasal (anterior), and the naso-palatine. 



The superior nasal branches (anterior), four or five in number, enter the back 

 part of the nasal fossa by the spheno-palatine foramen. They supply the mucous 

 membrane, covering the superior and middle spongy bones, and that lining 

 the posterior ethmoidal cells, a few being prolonged to the upper and back part 

 of the septum. 



The naso-palatine nerve (Cotunnius) enters the nasal fossa with the other 

 nasal nerves, and passes inwards across the roof of the nose, below the orifice 

 of the sphenoidal sinus, to reach the septum ; it then runs obliquely downwards 

 and forwards along the lower part of the septum, to the anterior palatine foramen, 

 lying between the periosteum and mucous membrane. It descends to the roof of 

 the mouth by a distinct canal, which opens below in the anterior palatine fossa ; 

 the right nerve, also in a separate canal, being posterior to the left one. In the 

 mouth, they become united, and supply the mucous membrane behind the incisor 

 teeth, joining with the anterior palatine nerve. It occasionally furnishes a few 

 small filaments to the mucous membrane of the septum. 



Fig. 281. The Spheno-palatine Ganglion and its Branches. 



The Posterior branches are the Yidian and pharyngeal or pterygo-palatine. 



The Vidian arises from the back part of the spheno-palatine ganglion, passes 

 through the Vidian canal, enters the cartilage filling in the foramen lacerum basis 

 cranii, and divides into two branches, the large petrosal and the carotid. In its 

 course along the Vidian canal, it distributes a few filaments to the lining membrane 

 at the back part of the roof of the nose and septum, and that covering the end 

 of the Eustachian tube. These are upper posterior nasal branches. 



The large petrosal branch (nervus petrosus superficialis major} enters the cranium 

 through the foramen lacerum basis cranii, having pierced the cartilaginous sub- 

 stance filling in this aperture. It runs beneath the Casserian ganglion and dura 



