G26 



CRANIAL NERVES. 



inwards, forming an arch on the side of the 1 neck, and lying upon the Stylo- 

 pharyngeus and the Middle Constrictor of the pharynx, above the superior 



laryngeal nerve. It then passes 



Fig. 348. Course and Distribution of the Eighth Pair beneath the Hyo-glossus, and 

 of Nerves - is finally distributed to the mu- 



cous membrane of the fauces, 

 and base of the tongue, the 

 mucous glands of the mouth 

 and tonsil. 



In passing through the jugu- 

 lar foramen, the nerve presents, 

 in succession, two gangliform 

 enlargements. The superior, 

 the smaller, is called ihejiigu- 

 lar ganglion, the inferior and 

 larger the petrous ganglion, or 

 the ganglion of Andersch. 



The superior, or jugular gan- 

 glion, is situated in the upper 

 part of the groove in which 

 the nerve is lodged during its 

 passage through the jugular 

 foramen. It is of very small 

 size, and involves only the 

 outer side of the trunk of the 

 nerve, a small fasciculus, pass- 

 ing beyond it, which is not 

 connected directly with it. 



The inferior, or petrous gan- 

 glion, is situated in a depres- 

 sion in the lower border of the 

 petrous portion of the temporal 

 bone; it is larger than the for- 

 mer, and involves the whole 

 of the fibres of the nerve. From, 

 this ganglion arise those fila- 

 ments which connect the glosso- 

 pharyngeal with other nerves 

 at the base of the skull. 



Its branches of communication 

 are with the pneumogastric, 

 sympathetic, and facial, and the 

 tympanic branch. 



The branches to the pneumo- 

 gastric are two filaments, one 

 to its auricular branch, and one 

 to the upper ganglion of the 

 pneumogastric. 



The branch to the sympa- 

 thetic is connected with the 

 superior cervical ganglion. 



The branch of communica- 

 tion with the facial perforates 

 the posterior belly of the Digastric. It arises from the trunk of the nerve below 

 the petrous ganglion, and joins the facial just after its exit from the stylo-mas- 

 toid foramen. 



The tympanic branch (Jacobson's nerve) arises from the petrous ganglion, and 



