30 TOPOGRAPHICAL ANATOMY OF THE 



(1) A. auHcularis profunda. — Later on the deep auricular artery- 

 will be found just behind the external acoustic meatus of the temporal 

 bone. It gains the interior of the external ear and supplies the skin 

 therein. A branch (the stylo-mastoid artery) from it passes into the 

 tympanum by way of the stylo-mastoid foramen. 



(2) Ramus lateralis. — The small lateral branch follows the posterior 

 free border of the conchal cartilage. 



(3) Rar)ius intermedins. (4) Ra7nus oiiedialis. — These two rami 

 arise from a common stem. The former runs along the middle of the 

 convex surface of the concha as far as the apex of the ear. The medial 

 ramus supplies the medial and anterior surfaces of the conchal cartilage. 



The lateral, intermediate, and medial rami are connected by 

 arciform anastomoses. 



A. auricularis anterior. — The anterior auricular artery is a 

 branch of the superficial temporal, from which it arises beneath the 

 parotid gland and just below the condyloid process of the mandible. 

 Its origin will be exposed later when the parotid is removed. The 

 artery crosses the zygomatic arch behind the mandibular articulation, 

 and is distributed to the muscles and skin anterior and medial to 

 the base of the ear. Its most anterior branch anastomoses with the 

 supra-orbital artery ; while another branch pierces the conchal car- 

 tilage and assists in the supply of blood to the skin within the ear. 



The veins of the ear are for the most part satellites of the 

 arteries ; but the posterior auricular joins the internal maxillary- 

 vein at some distance below the level of origin of the corresponding 

 artery, and the last part of the anterior auricular vein is large 

 since it is joined by the dorsal cerebral vein from the interior of 

 the cranium. 



The Nerves of the Ear. 



N. auricularis posterior. — The entire course of the posterior 

 auricular nerve cannot be demonstrated as yet, because it leaves 

 the seventh cerebral close to or within the stylo-mastoid foramen. 

 Accompanying the posterior auricular artery underneath the parotid 

 gland, the nerve divides into branches that supply the posterior and 

 superior auricular muscles and the skin on the convex face of the 

 conchal cartilage. 



The internal auricular nerve, a branch of the seventh cerebral, 

 from which it arises close to or in common with the posterior 

 auricular, cannot be examined at present, but may be noted as 

 one of those concerned in the innervation of the external ear. It 

 gains the interior of the cavity of the ear by piercing the conchal 



