'/'///; SPHENO-PALATINE d.\ \dUON 973 



The sensory fibres ascend In tlic soft palate, where they are probably connected with 

 peripheral taMe organs, and they arise; from the oellfl of the geniculate ganglion. The 

 motor fibres, if they exist, belong either to the facial nerve or to communicating 

 branches which have passed into it from other ner\ 



(6) The sympathetic root is the great deep petrosal portion of the Vidian 

 nerve. This root, which is of reddi.-h colour and of soft texture, springs from the 

 carotid plexus which lies on the outer side of the internal carotid artery in the carotid 

 canal. It enters the foramen laceruni through the apex of the petrous portion of the 

 temporal bone, and unites with the great superficial petrosal brunch of the seventh 

 nerve to form the Yidian nerve. 



The Vidian nerve (n. canalis pterygoidei) commences by the union of the great 

 superficial and deep petrosal nerves in the foramen laceruni, and runs forwards 

 through the pterygoid (Vidian) canal to the pterygo-palatine (spheno-maxillary) 

 fossa, where it terminates in Meckel's ganglion. While it is in the pterygoid canal the 

 Yidian nerve is joined by a sphenoidal filament from the otic ganglion, and it gi\es 

 branches to the upper and back part of the roof and septum of the nose, and to the 

 lower end of the Kustachian tube. 



(c) The sensory root usually consists of two spheno-palatine branches from the 

 maxillary nerve. The majority of the fibres of these roots do not join the ganglion, 

 but pass by its inner side and enter the palatine branches. 



Branches. The branches of the ganglion are orbital or ascending, internal or 

 nasal, descending or palatine, and posterior or pharyngeal. 



Ascending branches. The orbital or ascending branches are two or three 

 small twigs which enter the orbit through the inferior orbital (spheno-maxillary) 

 fissure and proceed, within the periosteum, to the inner wall of the orbit, where they 

 pass through the posterior ethmoidal foramen and through the foramina in the suture 

 behind that foramen to be distributed to the mucous membrane which lines the pos- 

 terior ethmoidal cells and the sphenoidal sinus. 



Internal branches. The internal or nasal branches are derived in part from 

 the inner side of the ganglion, but are also largely made up of fibres which pass 

 from the spheno-palatine branches of the maxillary nerve without traversing the 

 ganglionic substance. They are disposed in two sets, the lateral and the medial 

 (septal) posterior superior nasal branches. 



The lateral posterior superior nasal branches are six or seven small twigs 

 which pass through the spheno-palatine foramen, and are distributed to the mucous 

 membrane covering the posterior parts of the superior and middle nasal concha 

 (turbinated bones) (fig. 699) . They also furnish twigs to the lining membrane of the 

 posterior ethmoidal cells. 



The medial posterior superior nasal (septal) branches, two or three in number, 

 pass inwards through the spheno-pahrtine foramen. They cross the roof of the nasal 

 fossa to reach the back part of the nasal septum, where the smaller twigs terminate. 

 The largest nerve of the set, the naso-palatine nerve, or nerve of Cotunnius, runs 

 downwards and forwards in a groove in the vomer between the periosteum and the mu- 

 cous membrane to the incisive (anterior palatine) canal, where it communicates with the 

 nasal branch of the anterior superior alveolar nerve. The two naso-palatine nerves 

 then pass through the foramina of Scarpa in the intermaxillary suture, the left nerve 

 passing through the anterior of the two foramina. In the lower part of the incisive 

 (anterior palatine) canal the two nerves form a plexiform communication (formerly 

 described as Cloquet's ganglion) and they furnish twigs to the anterior or premaxillary 

 part of the hard palate behind the incisor teeth. In this situation they communicate 

 with the anterior palatine nerves. 



Descending branches. The descending branches are the great or anterior, 

 the posterior, and the middle (external) palatine nerves. Like; the internal set of 

 branches, they are in part derived from the ganglion and in part are directly con- 

 tinuous with the spheno-palatine nerves (fig. 699). 



The great or anterior palatine nerve arises from the inferior angle of 

 Meckel's ganglion, and passes downwards through the posterior palatine canal, 

 accompanied by the descending palatine artery. Emerging from the canal at 

 the greater (posterior) palatine foramen it divides into two or three branches, which 

 pass forwards in grooves in the hard palate and supply the glands and mucous mem- 

 brane of the hard palate and the gums on the inner aspect of the alveolar border of 

 the upper jaw. During its course through the posterior palatine canal the anterior 



