FACIAL NERVE. 391 



7th pair, FACIAL (portio dura.} The Facial nerve arises from 

 the respiratory tract, at the upper part of the medulla oblongata 

 close to the lower border of the pons Va^olii, from which point its 

 fibres may be traced deeply into the cdrpus restiforme. It enters 

 the meatus auditorius interims in front of and superiorly to the 

 auditory nerve (portio mollis), and at the bottom of the meatus 

 passes into the canal which is expressly intended for it, the aque- 

 ductus Fallopii. In this canal it directs its course at first forwards 

 towards the hiatus Fallopii, where it forms a gangliform swelling, 

 and receives the petrosal branch of the Vidian nerve. It then curves 

 backwards towards the tympanum, and descends along its inner 

 wall to the stylo-mastoid foramen. Emerging at the stylo-mastoid 

 foramen it passes forwards within the parotid gland, and crosses the 

 external jugular vein and external carotid artery to the ramus of the 

 jaw. While situated within the gland it is joined by a branch from 

 the auricular nerve, and divides into two trunks the temporo-facial 

 and cervico-facial which communicate with each other and give 

 off the numerous branches which constitute the pes anserinus, and 

 are distributed over the whole of the side of the face, supplying the 

 muscles. 



The Branches of the facial nerve are 



Within the aqueductus ( Tympanic, 

 Fallopii, \ (Chorda tympani).* 



r Communicating, 



After emerging at the j Posterior auricular, 

 stylo-mastoid foramen, \ Digastric, 

 S.tylo-hyoid. 



^ ,7 ,. ( Temporo-facial, 



On the face, r F } ' 



I Cervico-facial.f 



The Tympanic branches are two small filaments, which are 7 dis- 

 tributed to the stapedius and tensor tympani muscle. 



The Chorda tympani quits the facial just before that nerve emerges 

 from the stylo-mastoid foramen. Entering the tympanum at its 

 posterior and superior angle, it crosses its cavity between the handle 

 of the malleus and long process of the incus, to its anterior inferior 

 angle. It then escapes through a distinct opening in the fissura 

 Glaseri, and joins the gustatory nerve at an acute angle between 



* The chorda tympani is not considered as a branch of the facial ; but being in close 

 connexion with it, and being given off from it like a branch I have inserted it here 

 lest it should be overlooked. 



t A third series of branches is usually described, which are included by Wilson in 

 his temporo-facial branches. They are called buccal from supplying the neighbourhood 

 of the buccinator muscle. G. 



