1252 



HUMAN ANATOMY. 



the stylo-mastoid foramen the nerve passes downward, outward and forward through 

 the parotid gland, and divides, just posterior to the ramus of the mandible, into 

 its terminal branches, the temporo facial and the cervico-facial. The filaments of 

 these branches freely join with one another and form the fan-like parotid plexus 

 (plexus parotideus), also called pes anserinus. 



The geniculate ganglion (g. geniculi) is a small oval or fusiform thickening on 

 the facial nerve, at the point where it turns backward (geniculum n. facialis), and 

 contains unipolar neurones, whose axones form the sensory root of the facial nerve 

 and whose dendrites form the sensory fibres of distribution of the seventh. 



The so-called branches of the geniculate ganglion — the great and external 

 superficial petrosal nerves and the branches to the tympanic plexus — are only in part 

 composed of fibres connected with the ganglion cells ; they are, therefore, more 

 appropriately regarded as branches of the facial nerve. 



Branches and Distribution. — Within the facial canal, the facial nerve gives 

 off: (i) the great superficial petrosal, (2) the branch to the tympanic plexus, (3) 

 the external superficial petrosal, (4) the stapedial, (5) the chorda tympani and 



Fig. 1067. 



Diagram showing branches and connections of facial nerve within facial canal.- 



(6) the communicating branch to the vagus. The first three are closely connected 

 with the geniculate ganglion. Outside the facial canal arise: (7) the posterior auric- 

 ular, (8) the digastric, (9) the stylo-hyoid, (10) the temporo-facial 2iX\<\ (11) the 

 cervico-facial nerve. The last two nerves arise in an uncertain manner from that 

 irregular plexiform expansion, known as the pes anserinus, into which the facial 

 broadens within the substance of the parotid gland after emerging from the stylo- 

 mastoid foramen. 



1. The great superficial petrosal nerve (n. petrosus superficialis major) (Fig. 

 1061), while issuing directly from the ganglion, contains motor fibres in addition to the 

 sensory. It leaves the facial canal through the hiatus Fallopii, enters the middle cranial 

 fossa and passes forward under the Gasserian ganglion and over the cartilage of the 

 middle lacerated foramen. The nerve then crosses the outer side of the internal 

 carotid artery to reach the posterior opening of the Vidian canal, where it is joined- 

 by the great dee]) petrosal nerve (page 1360) from the carotid sympathetic plexus, 

 with which it unites to form the Vidiayi 7ierve. The latter traverses the Vidian 

 canal to the spheno-maxillary fossa and there enters the posterior aspect of the 

 spheno-palatine ganglion, whose motor and sympathetic roots it contributes. The 

 probable relations and destination of these fibres have been considered in connection 

 with the spheno-palatine ganglion (page 1240). 



2. The communicating branch to the tympanic plexus (r. anastomoticus 

 cum plexu tympanico) traverses a tiny canal in the temporal bone to reach the 

 tympanic cavity, where it joins the main continuation of the tympanic plexus of the 



