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3rd divison of the 5th; this nerve also sending fibres which enter 

 into the formation of the tympanic plexus through the small deep 

 petrosal nerve. 



Other sensory fibres also course with the motor trunk of the facial 

 in the aqueduct of Fallopius. These are of 2 kinds : The one composed 

 of fibres which pass in the chorda tympani to the anterior two-thirds 

 of the tongue, and subserve the function of the sense of taste ; the other 

 consisting of fibres of general sensation of geniculate origin, which 

 emerge with the trunk of the facial at the stylomastoid foramen, and 

 pass to the interior of the auricle. The geniculate ganglion, therefore, 

 has a splanchnic distribution within the cavity of the mouth and middle 

 ear and a somatic distribution on the external ear. 



In the lower - structural types the sensory system of the facial 

 nerve exceeds in importance its motor function. In the course of 

 phylogenic development its sensory system has diminished, while its 

 motor system has increased, so that in man the splanchnic distrbution 

 within the buccal cavity (exclusive of the taste function) must be re- 

 garded as more or less vestigial. But there still exists an important 

 sensory distribution of facial origin within the middle ear, including 

 its prolongations into the mastoid cells and Eustachian tube, as well as 

 on the external ear. 



There are also anastomotic filaments which pass from the geni- 

 culate ganglion to the auditory nerve at its termination (internal ear). 

 In man, therefore, save for a vestigial remnant of general sensation and 

 the chorda tympani within the mouth cavity, the sensory system of 

 the facial is confined to the innervation of the auditory mechanism. In 

 order to simplify the complicated anatomical nomenclature of this region, 

 for purposes of clinical description, the author suggests the following 

 reconstruction : 



The facial or 7th cranial nerve is composed of two roots, a motor 

 and a sensory, which unite at the level of the geniculate ganglion. On 

 the distal side of the ganglion the nerve is divided into three branches 

 or divisions, analogous to the terminology which has been assigned to 

 the trigeminus on the distal side of its ganglion. 



Peripheral divisions of the 7th nerve. 



First division: the great superficial petrosal nerve, passing to 

 Meckel's ganglion, and giving off in its course a tympanic branch, the 

 great deep petrosal. 



Second division : the small superficial petrosal nerve, passing to the 

 otic ganglion, and giving off in its course a tympanic branch, the 

 small deep petrosal. 



Third division: includes the motor trunk, the chorda tympani and 

 the sensory fibres destined for the external ear. Around this third 

 divion is grouped the well-known symptomatology of Bell's palsy. 



Such a reconstruction of the facial system, while perhaps not serv- 

 ing the purpose of the anatomist, who divides the branches of the 

 facial according to their relations to the temporal bone, into intra- and 



