154 HEAD AND NECK 



minence anterior to the meatus, and projecting posteriorly so 

 as to overshadow it, is termed the tragus, whilst a similar 

 eminence posterior to and below the meatus receives the name 

 of the antitragus. The notch between these two prominences 

 is termed the incisura intertragica. But it will be noted that 

 the upper end of the antihelix bifurcates, and in this way two 

 fossae are marked off from each other; one the fossa of the 

 helix, or scaphoid fossa is placed between the helix and the 

 antihelix, and the other the fossa of the antihelix, or triangular 

 fossa is situated between the two diverging crura of the 

 antihelix. 



j' Anterior. 



Ligaments, . ! Superior. 



[ Posterior. 



f Auricularis anterior. 

 Extrinsic muscles,^ Auricularis superior. 



[Auricularis posterior. 



C Musculus helicis major. ^ 



Musculus helicis minor. I Upon the lateral face of the 

 Tntrinsir mmwlM J Musculus tragicus. j cauilage. 



les ' I Musculus antitragicus. J 



J Musculus transversus. \ Upon the cranial face of 



[Musculus obliquus. / the cartilage. 



Dissection. When 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 two former spring from a lateral prolongation 

 of the galea aponeurotica into the temporal region. The anterior is 

 inserted into the front of the helix, and the superior into the cranial surface 

 of the auricle. To display them pull the auricle downwards and posteriorly, 

 and carefully remove the superficial fascia and, at the same time, avoid injury 

 to the auriculo-temporal nerve, the temporal branches of the facial nerve, 

 and the branches of the superficial temporal artery which are ascending 

 through the superficial fascia of the temporal region to the scalp. The 

 auricularis posterior arises from the outer surface of the mastoid part of 

 the temporal bone and passes anteriorly to its insertion into the cranial 

 aspect of the concha. To display it pull the auricle anteriorly and remove 

 the fascia from the surface of the muscle, at the same time secure the 

 posterior auricular artery and nerve as these ascend posterior to the external 

 meatus. As this is being done one or more mastoid lymph glands may 

 be seen, and care must be taken to avoid injuring the branch of the 

 posterior auricular nerve to the occipitalis muscle, which passes posteriorly 

 along the lower border of the auricularis posterior or on its deep surface. 



The auriculares muscles are supplied by the facial nerve ; the anterior 

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

 posterior and the posterior part of the superior by the posterior 

 auricular branch. After the auriculares muscles have been defined remove 

 the skin from the entire extent of the auricle to display the cartilage, the 

 ligaments, and the intrinsic muscles. 1 Great care is required to make a 

 successful dissection. 



1 In most cases it will be advisable to defer this part of the dissection till 

 the body is turned on its back for the second time (p. 200). 



