THE BRANCHES OF THE FIFTH NERVE. 733 



is 



forward, through the Vidian canal, with the artery of the same name, and L 

 joined by a small ascending branch, the sphenoidal branch, from the otic ganglion. 

 Finally, it enters the spheric-maxillary fossa, and joins the posterior angle of 

 Meckel's ganglion. 



Its branches of distribution are divisible into four groups : ascending, which 

 pass to the orbit ; descending, to the palate : internal, to the nose ; and posterior 

 branches, to the pharynx and nasal fossae. 



The ascending branches are two or three delicate filaments, which enter the 

 orbit by the spheno-maxillary fissure, and supply the periosteum. According to 

 Luschka, some filaments pass through foramina in the suture between the os 

 plarium of the ethmoid and frontal bones to supply the mucous membrane of the 

 posterior ethmoidal and sphenoidal sinuses. 



The descending or palatine branches are distributed to the roof of the mouth, 

 the soft palate, tonsil, and lining membrane of the nose. They are almost a direct 

 continuation of the spheno-palatine branches of the superior maxillary nerve, and 

 are three in number anterior, middle, and posterior. 



The anterior or large palatine nerve descends through the posterior palatine 

 canal, emerges upon the hard palate at the posterior palatine foramen, and passes 

 forward through a groove in the hard palate nearly as far as the incisor teeth. It 

 supplies the gums, the mucous membrane and glands of the hard palate, and 

 communicates in front with the termination of the naso-palatine nerve. While in 

 the posterior palatine canal it gives off inferior nasal branches, which enter the 

 nose through openings in the palate bone, and ramify over the inferior turbinated 

 bone and middle and inferior meatuses ; and at its exit from the canal a palatine 

 branch is distributed to both surfaces of the soft palate. 



The middle or external palatine nerve descends through one of the -accessory 

 palatine canals, distributing branches to the uvula, tonsil, and soft palate. It is 

 occasionally wanting. 



The posterior or small palatine nerve descends with a minute 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, 1 the 

 soft palate, tonsil, and uvula. The middle and posterior palatine join with the 

 tonsillar branches of the glosso-pharyngeal to form the plexus around the tonsil 

 (circulus tonsillaris). 



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 (Ootunnius) also enters the nasal fossa through the 

 spheno-palatine foramen, and passes inward across the roof of the nose, below 

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

 downward and forward 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 through the anterior palatine canal. The two nerves are here 

 contained in separate and distinct canals, situated in the intermaxillary suture, 

 and termed the foramina of Scarpa, the left nerve being usually anterior to the 

 right one. In the mouth they become united, supply the mucous membrane behind 

 the incisor teeth, and join with the anterior palatine nerve. The naso-palatine 

 nerve furnishes a few small filaments to the mucous membrane of the septum. 



The posterior branches are the pharyngeal (ptery go-palatine) and the upper 

 posterior nasal branches. 



The pharyngeal nerve (ptery go-palatine) is a small branch arising from the 



1 It is probable that this is not the true motor supply to these muscles, but that they are supplied 

 by the spinal accessory through the pharyngeal plexus. 



