AURICLE 45 



fossa or fossa of the helix. At the point where the posterior 

 border of the auricle turns forwards towards the superior 

 extremity there is, sometimes,' a small triangular prominence 

 which is known as Darwin's Tubercle. It represents the 

 apex of the ear of an ordinary quadruped. In front of the 

 meatus, and extending backwards to overshadow it, is a 

 triangular prominence called the tragus. It is separated 

 from the antitragus by a notch known as the intertragic 

 notch (indsura intertragica). Numerous hairs grow from the 

 posterior surface of the tragus. They become very prominent 

 in the male after the middle period of life. 



The ligaments and muscles connected with the auricle 

 are : 



( Anterior. 



Ligaments, . -j Superior. 



[Posterior, 

 f Auricularis anterior. 

 Extrinsic muscles, -! Auricularis superior. 

 [Auricularis posterior, 

 f Musculus helicis major. ^ 

 I Musculus helicis minor, i Upon the lateral face of the 



Intrinsic muscles J Musculus tragicus. j cartilage. 



ies ' j Musculus antitragicus. J 



j Musculus transversus. \Upon the cranial face of 



[Musculus obliquus. / the cartilage. 



Dissection. After the dissector has noted the various parts 

 of the auricle he should endeavour to display its extrinsic muscles ; 

 they are the auriculares anterior (O.T. attrahens), superior 

 (O.T. attollens), and posterior (O.T. retrahens). 



The auricularis anterior has already been dissected (see p. 14). 

 It passes from the deep fascia of the temporal region to the front 

 of the helix. To display the auricularis superior pull the upper 

 part of the auricle downwards and carefully remove the super- 

 ficial fascia above ft. The muscle fibres spring from the lateral 

 part of the galea aponeurotica and converge, as they descend, 

 to the medial surface of the auricle in the region of the floor of 

 the triangular fossa. After the auricularis superior has been 

 cleaned pull the auricle forwards and clean the auricularis 

 posterior. It is a thicker and more definite muscular bundle 

 which springs from the mastoid portion of the temporal bone, 

 above the mastoid process, and passes to the convexity on the 

 medial surface of the auricle which corresponds with the floor 

 of the concha. As the muscle is being cleaned one or more 

 small mastoid lymph glands may be seen, and care must be 

 taken to avoid injury to the branch from the posterior auricular 

 nerve to the occipitalis part of the epicranius. It passes back- 

 wards either along the lower border of the auricularis posterior 

 or under cover of that muscle. 



The auriculares muscles are supplied by the facial nerve ; 

 the anterior and the anterior part of the superior by its temporal 



