FACIAL NERVE. 553 



pharynx to the base of the tongue. In its course it receives one or two 

 branches from the glosso-pharyngeal nerve, which are nearly as large as the 

 original branch from the facial. As it passes to the base of the tongue, it 

 anastomoses again by a number of filaments with the glosso-pharyngeal. It 

 then sends filaments of distribution to the mucous membrane and finally 

 passes to the stylo-glossus and palato-glossus muscles. 



Having given oil these branches, the trunk of the facial passes through 

 the parotid gland, dividing into its two great terminal branches : 



1. The temporo-facial branch, the larger, passes upward and forward to 

 be distributed to the superficial muscles of the upper part of the face ; viz., 

 the attrahens aurem, the frontal portion of the occipito-frontalis, the orbicu- 

 laris palpebrarum, corrugator supercilii, pyramidalis nasi, levator labii supe- 

 rioris, levator labii superioris alaeque nasi, the dilators and compressors of the 

 nose, part of the buccinator, the levator anguli oris and the zygomatic mus- 

 cles. In its course it receives branches of communication from the auriculo- 

 temporal branch of the inferior maxillary nerve. It joins also with the tem- 

 poral branch of the superior maxillary and with branches of the ophthalmic. 

 It thus becomes a mixed nerve and is distributed in part to integument. 



2. The cervico-facial nerve passes downward and forward to supply the 

 buccinator, orbicularis oris, risorius, levator labii inferioris, depressor labii 

 inferioris, depressor anguli oris and platysma. 



General Properties of the Facial Nerve. It has long been recognized 

 that the facial is the motor nerve of the superficial muscles of the face and 

 that its division produces paralysis of motion and no marked effects upon 

 sensation. It is evident, also, from the communications of the facial with 

 the fifth, that it probably contains in its course sensory fibres. Indeed, all 

 who have operated upon this nerve have found that it is slightly sensory 

 after it has emerged from the cranial cavity. It is a question, however, of 

 great importance to determine whether or not the facial be endowed with 

 sensibility by virtue of its own fibres of origin. The main root is evidently 

 from the motor tract, resembles the anterior roots of the spinal nerves, and 

 is distributed to muscles ; but this root is joined by the intermediary nerve 

 of Wrisberg, which presents a small, ganglionic enlargement, that is analo- 

 gous to the ganglia upon the posterior roots of the spinal nerves. The testi- 

 mony of direct experimentation is in favor of the insensibility of the facial 

 at its origin. It is true that the intermediary nerve of Wrisberg has a cer- 

 tain anatomical resemblance to the sensory nerves, chiefly by reason of its 

 ganglioform enlargement ; but direct experiments are wanting to show that 

 it is sensory. 



Uses of the Branches of the Facial given off within the Aqueduct of Fal- 

 lopius. The first branch, the large petrosal, is the motor root of Meckel's 

 ganglion. This will be referred to again, in connection with the sympathetic 

 system. The second branch, the small petrosal, is one of the motor roots of 

 the otic ganglion of the sympathetic. The third branch, the tympanic, is 

 distributed exclusively to the stapedius muscle. The second and third 

 branches will be again considered, in connection with the physiology of the 



