THE HEAD AND NECK 1221 



palatine nerve traverses the groove on the lateral surface of the 

 vomer, it furnishes twigs to the mucous membrane of the nasal 

 septum, and in this part of its course it is accompanied by the naso- 

 palatine artery (artery of the septum) ; but this artery does not 

 accompany it through the foramen or canal of Scarpa. 



Descending Branches. — ^These are the great or anterior, the small 

 or posterior, and the external palatine nerves. They arise from 

 the lower part of the ganglion, usually by a common trunk, and they 

 derive some of their fibres from the spheno-palatine nerves. 



The great or anterior palatine nerve descends in the posterior pala- 

 tine canal, and escapes from it through the posterior palatine 

 foramen. Thereafter it divides into branches which pass forwards 

 and inwards, occupying grooves on the hard palate, to the mucous 

 membrane and glands of which, as well as to the mucous membrane 

 of the upper gum on its inner aspect, they are distributed. In the 

 region of the anterior palatine fossa this nerve communicates with 

 the naso-palatine nerve. As it descends in the posterior palatine 

 canal, it furnishes two inferior nasal nerves, which enter the nasal 

 fossa, and are distributed to the mucous membrane over the 

 inferior concha, except anteriorly, and to that of the adjacent por- 

 tion of the inferior meatus. The small or posterior palatine nerve 

 descends in the posterior accessory palatine canal, after emerging 

 from which it is distributed to the mucous membrane of the soft 

 palate and tonsil. It may furnish branches to the levator palati 

 and azygos uvulae muscles, the fibres of these branches being derived 

 from the geniculate ganglion of the facial through means of the great 

 superficial petrosal, which contributes to the formation of the Vidian 

 nerve, and conveys motor fibres to Meckel's ganglion. The two 

 muscles in question, however, are most probably supplied by the 

 bulbar part of the spinal accessory nerve through the pharyngeal 

 plexus. The external palatine nerve descends through the external 

 accessory palatine canal, after emerging from which it is distributed 

 to the mucous membrane of the outer portion of the soft palate and 

 tonsil. 



Summary of the Superior Maxillary Nerve and Meckel's Ganglion — 

 I. Cutaneous Distribution. — (i) The skin of the anterior part of the temporal 

 region, and over the malar bone ; (2) the skin from the lower eyelid down 

 to the upper lip, including the skin of the side of the nose ; (3) the mucous 

 membrane of the naso-pharynx in the vicinity of the Eustachian orifice ; 

 (4) the mucous membrane of the nasal fossa ; (5) the mucous membrane of 

 the antrum of Highmore ; (6) the mucous membrane of the soft palate and 

 tonsil ; and (7) the mucous membrane of the hard palate, with its glands, 

 and that of the inner surface of the upper gum. 2. Dental Distribution. — 

 The pulps of all the upper teeth of one side, as well as the mucous membrane 

 of the outer surface of the upper gum. 



In addition to the foregoing, the superior maxillary nerve supplies the 

 periosteum of the orbit, and the dura mater of the middle cranial fossa. 



Deep Dissection of the Neck. 



Stylo-pharyngeus — Origin. — ^The base of the styloid process of 

 the temporal bone on its inner aspect. 



