394 PNEUMOGASTRIC NERVE. 



The Brandies of the glosso-pharyngeal nerve are- 

 Communicating branches with the Facial, 



Pneumogastric, 

 Spinal accessory, 

 Sympathetic. 



Tympanic, 



Muscular, 



Pharyngeal, 



Lingual, 



Tonsillitic. 



The Branches of communication proceed from the ganglion and 

 from the upper part of the trunk of the nerve, and are common to 

 the facial,, eighth pair, and sympathetic ; they form a complicated 

 plexus at the base of the skull. 



The Tympanic branch (Jacobson's nerve) enters a small bony 

 canal in the petrous portion of the temporal bone, and divides into 

 six branches, which are distributed upon the inner wall of the tym- 

 panum, and establish important communications with the sympathetic 

 and fifth pair of nerves. The branches of distribution supply the 

 fenestra rotunda, fenestra ovalis, and Eustachian tube: those of 

 communication join the carotid plexus, the petrosal branch of the 

 Vidian nerve, and the otic ganglion. 



The Muscular branch divides into filaments, which are distributed 

 to the stylo-pharyngeus and to the posterior belly of the digastricus 

 and stylo-hyoideus muscle. 



The Pharyngeal branches are two or three filaments which are 

 distributed to the pharynx and unite with the pharyngeal branches 

 of the pneumogastric and of the sympathetic nerve to form the 

 pharyngeal plexus. 



The Lingual branches enter the substance of the tongue beneath 

 the hyo-glossus and stylo-glossus muscle, and are distributed to the 

 mucous membrane of the side- and base of the tongue, and to the 

 fauces. 



The Tonsillitic branches proceed from the glosso-pharyngeal nerve 

 near to its termination ; they form a plexus (circulus tonsillaris) 

 around the base of the tonsil, from which numerous filaments are 

 given off to the mucous membrane of the fauces and soft palate, 

 communicating with the posterior palatine branches of Meckel's 

 ganglion. 



The PNEUMOGASTRIC NERVE (vagus) arises by numerous filaments 

 from the respiratory tract immediately below the glosso-pharyngeal, 

 and passes out of the skull through the inner extremity of the 

 jugular foramen in a distinct canal of the dura mater. While 

 situated in this canal it presents a small rounded ganglion ; and 

 having escaped from the skull, a gangliform swelling, nearly an inch 

 in length, and surrounded by an irregular plexus of white nerves. 



