THE EAR. 



913 



also between the tragus and beginning of the helix, the notch between them being 

 filled up by dense fibrous tissue. At the front part of the pinna, where the helix 

 bends upward, is a small projection of cartilage, called the process of the helix. 

 The cartilage of the pinna presents several intervals or fissures in its substance 

 which partially separate the different parts. The fissure of the helix is a short 

 vertical slit situated at the fore part of the pinna, immediately behind a small 

 conical projection of cartilage, opposite the first curve of the helix (process of the 

 helix). Another fissure, the fissure of the tragus, is seen upon the anterior sur- 

 face of the tragus. The antihelix 

 is divided below, by a deep fissure, 

 into two parts : one part termi- 

 nates by a pointed, tail-like ex- 

 tremity (processus caudatus); the 

 other is continuous with the anti- 



tragus. The cartilage of the ^\ \\\\\\ 



V IVB 



FIG. ."39. The pinna, or auricle. 

 Outer surface. 



FIG. 540. The muscles of the pinna. 



pinna is very pliable, elastic, of a yellowish color, and belongs to that form of 

 cartilage which is known under the name of yellow fibro-cartilage. 



The ligaments of the pinna consist of two sets : 1. The extrinsic set, or those 

 connecting it to the side of the head. 2. The intrinsic set, or those connecting the 

 various parts of its cartilage together. 



The extrinsic ligaments, the most important, are two in number, anterior and 

 posterior. The anterior ligament extends from the process of the helix to the root 

 of the zygoma. A few fibres connect the tragus to the root of the zygoma. The 

 posterior ligament passes from the posterior surface of the concha to the outer 

 surface of the mastoid process of the temporal bone. 



The intri/txt'- ligaments are also two in number. Of these, one is a strong 

 fibrous band stretching across from the tragus to the commencement of the helix, 

 completing the meatus in front and partly encircling the boundary of the concha ; 

 the other extends between the concha and the processus caudatus. 



The muscles of the pinna (Fig. 540) consist of two sets: 1. The extrinsic, 

 which connect it with the side of the head, moving the pinna as a whole viz. the 

 Attollens. Attrahens, and Retrahens aurem (page 394); and 2. The intrinsic, which 

 extend from one part of the auricle to another viz. : 



Helicis major. 

 Helicis minor. 

 Trasicus. 



Antitragicus. 

 Transversus auriculae. 

 Obliquus auris. 



