762 



SPECIAL SENSES. 



the inferior peduncle of the cerebellum, between the roots of the auditory nerve above 

 and the pneumogastric below. A number of its filaments of origin come from the 

 medulla and a portion from the peduncle. The deep origin is nearly the same as that of 

 the pneumogastric, its filaments arising primarily from the gray substance of the medulla 

 oblongata. From this origin, the filaments pass forward and outward to the posterior 

 foramen lacerum, which the nerve enters in company with the pneumogastric, the spinal 

 accessory, and the internal jugular vein. At the upper portion of the foramen, is a small 

 ganglion, the jugular ganglion, including only a portion of the root. Within the foramen, 

 is the main ganglion, including aU of the filaments of the trunk, called the petrous gan- 

 glion, or the ganglion of Andersch, after the anatomist by whom it was first described. 



At or near the ganglion of Andersch, the glosso-pharyngeal usually receives a delicate 

 filament from the pnenmogastric. This communication is sometimes wanting. The 

 same may be said of a small filament passing to the glosso-pharyngeal from the facial, 

 which is not constant. Branches from the glosso-pharyngeal go to the otic ganglion and 

 to the carotid plexus of the sympathetic. 



FIG. 235. Glosso-pharyngeal nerve. (Sappey.) 



1. large root of the fifth nerve ; 2, ganglion of Gasser ; 3, ophthalmic division of the fifth ; 4, superior maxillary division ; 

 5, inferior maxillary division ; 6, 10, lingual branch of the fifth, containing the filaments of the chorda tym- 

 pani ; 7, branch from the sublingual to the lingual branch of the fifth ; 8, chorda tympani ; 9, inferior dental 

 nerve; 11, submaxillary ganglion; 12, mylo-hyoid branch of the inferior dental nerve; 13, anterior belly of the 

 digastric muscle ; 14, section of the mylo-hyoid muscle ; 15, 18, glosso-pharyngeal nerve; 16, ganglion of An- 

 dersch ,' 17, branches from tlw, glosso-pharyngeal to the sti/lo-glossus and the stylo-pharyngeus muscles ; 

 19, 19. pneumogastric ; 20, 21, ganglia of the pneumogastric ; 22, 22, superior laryngeal nerve ; 23, spinal accessory ; 

 24, 25, 26, 27, 28, sublingual nerve and branches. 



The distribution of the glosso-pharyngeal is quite extensive. The tympanic branch, 

 the nerve of Jacobson, arises from the anterior and external part of the ganglion of 

 Andersch, and enters the cavity of the tympanum, where it divides into six branches. 

 Of these six branches, two posterior are distributed to the mucous membrane of the 

 fenestra rotunda and the membrane surrounding the fenestra ovalis ; two anterior are 



