46 TOPOGRAPHICAL ANATOMY OF THE 



in contact with the joint-capsule, and over the root of the zygomatic 

 arch. It now passes underneath the anterior auricular muscles, and is 

 distributed over the surface of the temporal muscle. A small branch 

 accompanies the internal auricular nerve, and another anastomoses with 

 the supra-orbital artery. 



N. FACIALIS. — The facial or seventh cerebral nerve leaves the facial 

 canal by the stylomastoid foramen. From this point the nerve passes 

 obliquely downwards and forwards, on the lateral face of the 

 diverticulum of the auditory (Eustachian) tube and underneath the 

 parotid gland, to cross the border of the mandible just below the condy- 

 loid process. Having gained the border of the masseter, the nerve — 

 which has gradually become broader and flatter — divides into the dorsal 

 and ventral buccal nerves, an examination of which was made during 

 the dissection of the face (page 36). 



In its course the facial nerve crosses the posterior auricular artery 

 laterally, and, near its termination, passes between the superficial 

 temporal artery and vein close to the point of division of the former. 



The following are the branches of the facial nerve after its exit from 

 the facial canal : — 



(1) N. auricularis posterior. — The posterior auricular nerve arises 

 close to or even within the stylomastoid foramen, passes upwards and 

 backwards over the aponeurotic tendon of the splenius muscle, and ends 

 behind the ear as has been noted previously (page 30). 



(2) N. auricularis internus. — Arising close to the stylomastoid 

 foramen, the small internal auricular nerve runs upwards, generally in 

 the substance of the parotid gland, to pierce the conchal cartilage close 

 to the base of its styloid process. 



(3) iY. digastricus. — The thin digastric nerve runs vertically 

 downwards to end in the jugulo-hyoid and digastric (posterior belly) 

 muscles. Close to its origin from the facial, it furnishes a small branch 

 that, forming a loop round the posterior auricular artery, rejoins the 

 stem of the parent nerve. 



(4) N. auriculopalpehralis. — The auriculo- palpebral nerve is the 

 largest collateral branch of the facial. Leaving the parent stem about 

 two-thirds the distance between the stylomastoid foramen and the edge 

 of the mandible, it passes upwards over the root of the zygomatic arch 

 and crosses the anterior auricular vessels. The further continuation of 

 the nerve between the scutular and temporal muscles, and its concern 

 in the formation of a plexiform union with the frontal and lachrymal 

 nerves have already been observed (page 36). 



(5) Ramus colli. — The small cervical ramus leaves the facial at the 



