THE FACIAL NERVE 



945 



geus, and runs downward along the anterior border of the latter muscle to the wall of the 

 pharj-nx. It pierces the superior constrictor, insinuates itself between the tonsU and the anterior 

 pillar of the fauces, and it is stated that it gives filaments to the base of the tongue and to the 

 stylo-glossus and glosso-palatinus (palato-glossus) muscles. 



The terminal divisions.— In the substance of the parotid gland the two 

 terminal divisions of the facial nerve lie superficial to the external carotid artery 

 and to the posterior facial (temporo-maxillarj^ vein. The way in which these 

 terminal divisions give off their branches varies much in different subjects and 

 often on the opposite sides of the same subject. One of the more common forms 

 is here described. 



The tempore -facial or upper division runs upward and forward, and, after 

 receiving communicating twigs from the auriculo-temporal nerve, gives off tem- 

 poral and zygomatic (malar) branches. The cervico -facial or lower division runs 

 downward and forward, receives branches from the great auricular nerve, and 



I'lG. 7.39. — The Right Facial Nerve, within the Skull, and the Relations of the 



Glosso-palatine and Glosso-pharyngeal Nerves with the Tympanic and 



Internal Carotid Plexuses. (From Sobotta's Atlas, modified.) 



Tensor tympani muscle Deep petrosal nerve 



Auditory (Eustachian) tube 

 Superior carotico-tympanic a 

 Great superficial petrosal n 



Ramus anastomotic with tympanic plexus 

 Geniculate ganglion 

 Glosso-palatine n 

 Stapes Facial n 

 Tympamc smus 

 Stapedius muscle 

 Stapedius 

 nerve 



Small superficial 

 petrosal n. 



Internal 

 carotid plexus 



Maxillary nerve (lifted) 

 ' Nerve of pterygoid canal 

 (Vidian) 

 Spheno-palatine ganglion 



Mastoid cells 

 Chorda tympani 

 Stylo-mastoid foramen 



Tympanic nerve 

 Petrosal ganglion of glosso- 

 pharyngeal 

 Nodosal ganglion of vagus , 

 Superior cervical sympathetic ganglion 



Internal pterygoid 

 muscle 

 Ramus tubse 

 Promontorium 

 Inferior carotico-tympanic nerve 

 Internal carotid nerve 



gives off — (1) buccal branches, comprising what have been called infraorbital 

 and buccal branches; (2) the marginal mandibular (supra-mandibular) branch; 

 and (3) the ramus colli (infra-mandibular branch). These branches from the 

 two terminal divisions anastomose freely to form the parotid plexus (pes anserinus) . 



The temporal branches passing upward communicate freely with each other and with the 

 zygomatic branches. They also communicate with the zygomatico-temporal branch of the 

 zygomatic nerve (the orbital branch of the maxillary nerve) and with the supra-orbital nerve. 

 They supply the frontahs, orbicularis oculi, corrugator supercilii, and auricularis anterior and 

 superior (fig. 740). 



The zygomatic (malar) branches passing upward and forward, commimicate with the buccal 

 branches of the facial nerve; with the zygomatico-facial branch of the zygomatic nerve (the 

 orbital branch of the maxiUary nerve) ; with the supraorbital and lacrimal branches of the oph- 

 thalmic nerve, and with the palpebral twigs of the maxillar>\ They supply both ej'ehds, the 

 orbicularis oculi, and the zj-gomaticus (fig. 740). 



The buccal (infra-orbital and buccal) branches arise sometimes from the lower terminal 

 division and sometimes from both the upper and the lower terminal divisions. The buccal 

 branches, passing forward upon the masseter and underneath the zygomaticus and quadratus 

 labii superioris, interlace with the zygomatic and marginal mandibular (supra-mandibular) 

 branches of the facial nerve, with the buccinator (long buccal) branch of the trigeminus, and with 

 the terminal branches of the maxiUary nerve, forming with the last-named nerve the infra- 

 orbital plexus. They supply the zygomaticus, risoriUs, quadratus labii superioris, caninus, 



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