AURICLE 153 



enter from the periphery, passing into the superficial fascia 

 after piercing the deep fascia of adjacent regions. As a 

 consequence of this arrangement large flaps of the scalp may 

 be torn from the centre towards the margin, but, so long as 

 they remain attached at the periphery, their sources of 

 vitality are not seriously interfered with, and if they are cleaned 

 and replaced healing occurs rapidly and satisfactorily. 



Dissection. The skin has already been removed from the anterior 

 parts of the scalp and the temporal region. A median longitudinal in- 

 cision must now be made through the skin of the posterior part of the 

 scalp as far as the external occipital protuberance, and the flap on either 

 side of the incision must be turned downwards and posteriorly to the 

 superior nuchal line. When this has been done the dissector should ex- 

 amine the auricle of the external ear, and familiarise himself with its various 

 parts before he commences the dissection of its extrinsic muscles. 



FIG. 69. The Auricle. 



Auricle or Pinna. The auricle consists of a thin plate of 

 yellow nbro-cartilage, covered with integument. It is fixed in 

 position by certain ligaments, and possesses two sets of feeble 

 muscles viz., one group termed the extrinsic muscles, passing 

 to the cartilage from the aponeurosis of the epicranius and 

 the mastoid process,. and a second group in connection with 

 the cartilage alone, and therefore called the intrinsic muscles. 



The concha is the wide arid deep fossa which leads into 

 the external meatus ; the antilielix is the curved prominence 

 which bounds this posteriorly ; the helix is the folded or in- 

 curved margin of the auricle ; and the lobule is its soft 

 dependent part. The concha is partially subdivided into an 

 upper and a lower part by the commencement of the helix, 

 which curves upwards and forwards on its floor to become 

 continuous with the anterior border of the auricle. This 

 portion of the helix is called the crus helicis. A small pro- 



