FACIAL NERVE, OR NERVE OF EXPRESSION. 621 



ingly delicate branch is given off, which is not noticed in most works on anatomy. It is 

 described, however, by Hirschfeld, under the name of the lingual branch. It passes 

 behind the stylo-pharyngeal muscle, and then by the sides of the 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 numerous filaments with the glosso- 

 pharyngeal. It then sends filaments of distribution to the mucous membrane, and finally 

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



Having given off these branches, the trunk of the facial passes through the parotid 

 gland, dividing into its two great terminal branches : 



1. The temp oro -facial branch, the larger, passes upward and forward to be distrib- 

 uted to the superficial muscles of the upper part of the face ; viz., the attrahens aurem, 

 the frontal portion of the occipito-frontalis, the obicularis palpebrarum, corrugator super- 

 cilii, pyramidalis nasi, levator labii superioris, levator labii superioris alseque nasi, the 

 dilators and compressors of the nose, part of the buccinator, the levator anguli oris, and 

 the zygomatic muscles. In its course, it receives branches of communication from the 

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

 branch of the superior maxillary and with branches of the ophthalmic. In its course, 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. 



Summary of the Anastomoses and Distribution of the Facial. In the aquseductus 

 Fallopii, filaments of communication go to Meckel's ganglion and the otic ganglion of 

 the sympathetic. The chorda tympani joins the lingual branch of the inferior maxil- 

 lary division of the fifth. A branch is also sent to the pneumogastric. After the nerve 

 has passed out by the stylo-mastoid foramen, it sends a communicating branch to the 

 glosso-pharyngeal, and receives a branch from the auricularis inagnus. It anastomoses, 

 also, outside of the cranium, with the glosso-pharyngeal. In the course of the nerve, it 

 receives anastomosing filaments from the three great divisions of the fifth. 



It is thus seen that the facial, in its course, receives numerous filaments from the great 

 sensitive nerve of the face. Certain of its fibres of distribution go to integument. 



The muscles supplied by the facial are the stapedius, and probably the tensor tym- 

 pani, of the internal ear, the muscles of the external ear, the occipito-frontalis, the pos- 

 terior belly of the digastric, the stylo-hyoid, the stylo-glossus, and the palato-glossus. 

 The two great branches of distribution, the teinporo-facial and the cervico-facial, are 

 distributed to all of the superficial muscles of the face, leaving the deep muscles, or the 

 muscles of mastication, to be supplied by the motor root of the fifth. In addition, it 

 supplies in part the platysma myoides. 



Properties and Functions 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 pro- 

 duces paralysis of motion and no marked effects upon sensation. It is evident, also, 

 from the numerous communications of the facial with the fifth, that it probably contains 

 in its course sensitive fibres. Indeed, all who have operated upon this nerve have found 

 that it is slightly sensitive 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 mus- 

 cles ; but this is joined by the intermediary nerve of Wrisberg, which presents a small 

 enlargement, undoubtedly containing nerve-cells, somewhat analogous to the ganglia 

 upon the posterior roots of the spinal nerves. 



Direct observations upon the properties of the facial as it penetrates the auditory 



