AURICLE OF THE EAR. ^71 



back of the helix. The muscle is mixed with much fibrous tissue, 

 but it is well seen when that tissue is removed. 



Dissection. The remaining skin should now be removed from Clean the 

 the pinna, and the muscles cleaned off to expose the cartilage : in ^ 

 doing this the lobule of the ear, which consists only of skin and 

 fat, will disappear as in fig. 208. 



The cartilage of the pinna (fig. 208) resembles much the external Cartilage 

 ear in form, and presents nearly the same parts. The rim of the O f external 

 helix subsides posteriorly about the middle of the pinna: while ear: 

 anteriorly a small process projects from it, and there is a fissure 

 near the projection. The part of the cartilage forming the fossa of 

 the helix ends on a level with the lowest part of the concha in a efi eient 

 pointed process which is separated from the antitragus by a deep 

 notch. The antihelix is continued below into the antitragus. On 

 the posterior aspect of the concha is a strong vertical ridge of 

 cartilage. 



Inferiorly the cartilage is fixed to the margin of the external and at upper 

 auditory aperture in the temporal bone, and forms a portion of the meatus; 

 rneatus auditorius ; but it does not give rise to a complete tube, for 

 at the upper and hinder part that canal is closed by fibrous tissue. 



In the piece of cartilage forming the outer end of the ineatus its assures, 

 are two fissures (of Santorini) : one is directed vertically beneath 

 the base of the tragus ; the other passes from before backwards in 

 the floor of the meatus. 



Some ligaments connect the pinna with the head, and others pass Ligaments; 

 from one point to another of the cartilage. 



The external ligaments are two bands of fibrous tissue, anterior extrinsic, 

 and posterior. The anterior fixes the fore part of the helix to the 

 root of the zygoma. The posterior passes from the back of the 

 concha to the mastoid process. The chief special ligament crosses intrinsic, 

 the interval between the tragus and the helix, and completes the 

 opening of the auditory ineatus. 



Vessels and n> rres of the auricle. The arteries of the auricle 

 are derived from the superficial temporal (ant. auricular branches) 

 and the posterior auricular branches of the external carotid. The 

 veins have a corresponding termination. The skin of the pinna is 

 supplied on the outer surface mainly by the auricular-temporal branch 

 of the inferior maxillary nerve, on the inner surface in the upper 

 part by the small occipital, and in the lower part, together with 

 the outer aspect of the lobule, by the great auricular nerve. The 

 auricular branch of the vagus also reaches the back of the concha. 

 The muscles are supplied by the posterior auricular branch of the 

 facial nerve. 



