498 NEUROLOGY. 



where it bends upon itself and forms a slight enlargement, the 

 genicular ganglion, making its exit through the stylo-mastoid 

 foramen, where it lies deeply buried beneath the parotid gland. 

 Afterwards, inflected forwards, it passes between the gland and 

 the guttural pouch to gain the posterior border of the maxilla, 

 round the cervix of which it turns, and, reaching the external 

 surface of the masseter muscle, terminates in two or three branches, 

 which anastomose with the subzygomatic branch of the fifth, 

 forming the subzygomatic plexus. At the genicular ganglion the 

 seventh nerve is joined by a slender cord, the Tiei^'e of Wrisherg, 

 which is regarded by some authorities as the sensory root of the 

 seventh, by others as a connecting medium between the seventh 

 and eighth nerves. 



In its course the facial nerve gives off numerous branches ; 

 some before leaving the bone, the intraosseous, and some after 

 leaving it, extraosseous. 



The intraosseous branches are the superficial petrosal, which, 

 leaving the genicular ganglion, re-enters the crauial cavity by the 

 Fallopian hiatus, and passing through the cavernous sinus, it 

 receives a branch from the cavernous plexus of the sympathetic. 

 The nerve thus formed — the Vidian nerve — traverses the fissure 

 and conduit of the same name and gains the orbital hiatus, where 

 it joins Meckel's ganglion, to which it thus supplies motor and 

 sympathetic roots. A little to the outside of the above, the lesser 

 superficial peti'osal iurnishes motor fibres to the otic ganglion, 

 and a small filament supplies the stapedius muscle. The cJiorda 

 tyrnpani branch is given off in the aqueduct of Fallopius. It 

 enters the cavity of the tympanum, passes through the middle of 

 the chain of small bones, or auditory ossicles, and, leaving the 

 C9,vity through the Glaserian fissure, after a short course under 

 the pterygoid muscle, joins the lingual branch of the fifth. The 

 last intraosseous branch is one which anastomoses with the 

 pueumogastric. 



After emerging from the stylo-mastoid foramen, the facial 

 nerve gives off styloid branches to the stylo-hyoid and digastricus 

 muscles ; a cervical branch, which passes downwards below the 

 deprimens aurem muscle to the panniculus and skin of the neck ; 

 twigs to the guttural pouch and parotid gland ; and lastly, the 

 anterior, posterior, and middle auricular nerves. 



The anterior auricular nerve ascends over the front of the 

 ear, supplying the muscles and uniting with branches of the fifth. 



