NERVES 153 



anterior belly of occipito-frontalis, joining lachrymal and 

 supra-orbital nerves. 



Malar : to supply eyelid muscles, and join supra-orbital. 



Infra-orbital : superficial, to superficial muscles of the face, 

 join infra- trochlear, and nasal (5th). Deep, to elevators of 

 upper lip and angle of mouth, join infra-orbital of superior 

 maxillary. 



The CERVICO-FACIAL passes downwards and forwards in 

 parotid, receiving communications from the great auricular 

 nerve. 



Branches of the Cervico- facial : 



Buccal : to buccinator and orbicularis oris ; joins buccal 

 of inferior maxillary. 



Supra-mandibular : to muscles of lip and chin ; join mental 

 branch of inferior dental. 



Infra-mandibular : perforates deep cervical fascia be- 

 neath lower jaw, to join superficial cervical and supply 

 platysma. 



The STH or AUDITORY NERVE. Origin Superficial : Mesial 

 Root : between pons and restiform body. Lateral Root : floor 

 of the 4th ventricle, by the striae acusticae. Deep both roots: 

 auditory nuclei in floor of 4th ventricle. 



Course. Passes round restiform body to posterior border 

 of crus cerebelli with facial ; it then enters the internal 

 auditory meatus with, the facial nerve, the latter lying in a 

 groove on its upper surface, and divides at the bottom into 

 coJilear and vestibular branches. 



Distribution. Cochlear, supplies cochlea, saccule and 

 posterior semicircular canal ; vestibular, to utricle and 

 superior and external semicircular canals (vide Ear, p. 236). 



The QTH or GLOSSO-PHARYNGHAL NERVE. Origin Super- 

 ficial: from the upper part of the medulla, in the groove 

 between the olive and restiform body. Deep : floor of 4th 

 ventricle. 



Course. Passes outwards over the flocculus to the jugular 

 foramen. Leaves the skull with the pneumogastric and spinal 

 accessory, but in a separate tube of dura mater and in front 

 and external to them, being contained in a canal in the 

 petrous part of the temporal bone. It presents near point of 

 exit two ganglionic enlargements the jugular and petrous. 

 Issuing from the skull, the nerve passes downwards and out- 

 wards between the internal carotid artery and jugular vein, 

 and then forwards over the internal carotid artery, down- 

 wards behind the muscles attached to the styloid process, to 

 reach the lower border of the stylo-pharyngeus. Thence it 



