342 NEUROLOGY, OR ANATOMY OF NERVOUS SYSTEM 



Ascending. Several through the sphenomaxillary fissure to 

 the orbit. They may supply the periosteum. 



Descending. The small or posterior runs with a small artery 

 in the lesser palatine canal. It supplies the leva tor palati 

 and azygos uvulre. 



The large or anterior runs in the posterior palatine canal, 

 thence in branches to the incisor teeth along grooves in the 

 hard palate, and one joins the nasopalatine nerve. It gives 

 off inferior nasal branches, through canals in the palate bone, 

 to supply the spongy bones. 



The external to the outer part of the soft palate, through 

 the external palatine canal. 



The internal branches include the nasopalatine and the 

 upper nasal nerves. The latter run through the sphenopalatine 

 foramen to the spongy bones and septum. The nasopalatine 

 nerve proceeds with the above, and then descends on the 

 septum nasi, beneath the pituitary membrane, and through 

 the mesial divisions of the anterior palatine canal, called the 

 foramina of Scarpa, the left anterior to the right. They supply 

 the mucous membrane behind the incisor teeth. 



The Vidian is formed by the large superficial petrosal and the 

 large deep petrosal nerves. The former is a motor branch from 

 the geniculate ganglion of the facial in the aquseductus Fallopii; 

 it passes through the hiatus canalis facialis, enters the cranial 

 cavity, runs in a groove on the anterior surface of the petrous 

 portion of the temporal bone, beneath the dura. It then 

 pierces the cartilaginous substance enclosing the foramen lacerum 

 medium, and joins the large deep petrosal. The large deep 

 petrosal is given off from the carotid plexus, passing external 

 to the internal carotid artery. It pierces the cartilaginous sub- 

 stance of the foramen lacerum medium, and joins the large 

 superficial petrosal. Tlue Vidian begins from the cartilaginous 

 substance of the foramen lacerum medium, then passes through 

 the Vidian Canal, with the artery of the same name, and is 

 joined by a branch from the otic ganglion. It ends in Meckel's 

 ganglion. 



Posterior Branches. The pharyngeal nerve passes through 

 the pterygopalatine canal to the mucous membrane of the 

 pharynx. 



The inferior maxillary nerve (third division of the fifth) is 

 the largest branch, and arises by two roots a large sensor 



