AUDITORY NERVE. 



403 



raeatus and mastoid process, and divides into an anterior and a poste- 

 rior branch. The anterior branch receives a filament of communication 



Fig. 182.' 



from the auricular branch of 

 the pneumogastric nerve, and 

 distributes filaments to the re- 

 trahens and attollens aurem 

 muscles and to the pinna. 

 The posterior branch commu- 

 nicates with the auricularis 

 magnus and occipitalis minor, 

 and is distributed to the poste- 

 rior belly of the occipito-fron- 

 talis. 



The Stylo-hyoid branch is 

 distributed to the stylo-hyoid 

 muscle. 



The Digastric branch sup- 

 plies the posterior belly of the 

 digastricus muscle, and com- 

 municates with the glosso- 

 pharyngeal and pneumogastric 

 nerve. 



The Temporo-facial gives off a number of branches, which are distri- 

 buted over the temple and upper half of the face, supplying the muscles 

 of this region, and communicating with the branches of the auricular, the 

 subcutaneus malae, and the supra-orbital nerve. The inferior branches, 

 which accompany Stenon's duct, and form a plexus with the terminal 

 branches of the infra-orbital nerve. 



The Cervico-facial divides into a number of branches that are distri- 

 buted to muscles on the lower half of the face and upper part of the neck. 

 The cervical branches form a plexus with the superficialis colli nerve over 

 the submaxillary gland, and are distributed to the platysma myoides. 



AUDITORY NERVE (portio mollis). The auditory nerve takes its origin 

 in the lineae transverse (striae medullares) of the anterior wall or floor of 

 the fourth ventricle, and winds around the corpus restiforme, from which 

 it receives fibres, to the posterior border of the crus cerebelli. It then 

 passes forwards upon the crus cerebelli in company with the facial nerve, 

 which lies in a groove on its superior surface, and enters the meatus 



* The distribution of the facial nerve and the branches of the cervical plexus. 1. The 

 fecial nerve, escaping from the stylo-mastoid foramen, and crossing the ramus of the 

 lower jaw ; the parotid gland has been removed m order to see the nerve more dis- 

 tinctly. 2. The posterior auricular branch ; the digastric and stylo-mastoid filaments 

 are seen near the origin of this branch. 3. Temporal branches, communicating with 

 (4) the branches of the frontal nerve. 5. Facial branches, communicating with (6) the 

 infra-orbital nerve. 7. Facial branches, communicating with (8) ihe mental nerve. 

 &. Cervico-facial branches, communicating with (10) the superficialis colli nerve, and 

 forming a plexus (11) over the submaxillary gland. The distribution of the branches 

 of the facial in a radiated direction over the side of the face and theii looped commu- 

 nications constitute the pes anserinus. 12. The auricularis magnus nerve, one of th^ 

 ascending branches of the cervical plexus. 13. The occipitalis minor, ascending along 

 the posterior border of the sterno-mastoid muscle. 14. The superficial and deep de- 

 scending branches of the cervical plexus. 15. The spinal accessory nerve, giving off a 

 branch to the external surface of the trapezius muscle. 16. The occipitalis major nerve, 

 the nosterior branch of the second cervical nerve. 



