742 



THE EAR. 



from the lobule, which contains only fat and tough connective tissue. 

 Behind the antitragus is a deep notch, separating it from the cartilage of the 

 helix, which here forms a tail-like process descending towards the lobule. At 

 the fore part of the pinna, opposite the first bend of the helix, is a small 

 conical projection of the cartilage, called the process of the, helix, to which 

 the anterior ligament is attached. Behind this process is a short vertical 

 slit in the helix ; and on the surface of the tragus is a similar but somewhat 

 longer fissure. A deep fissure passes back between the commencement of 

 the helix and the tube of the ear, and another passing outwards and 

 backwards from the deep end of the longitudinal cleft separates the part 

 forming the tragus from the rest of the tube, so that the tube is continuous 

 with the pinna only by means of a narrow isthmus. One or two other 

 irregular gaps or fissures partially divide the cartilaginous tube transversely, 

 and the whole of these deficiencies are termed fissures of Santorini. The 

 substance of the cartilage is very pliable, and is covered by a firm fibrous 

 perichondrium. 



Of the ligaments of the pinna, the most important are two, which assist 

 in attaching it to the side of the head. The anterior ligament, broad and 

 strong, extends from the process of the helix to the root of the zygoma. 

 The posterior ligament fixes the back of the auricle (opposite the concha) to 

 the outer surface of the mastoid process of the temporal bone. A few fibres 

 attach the tragus also to the root of the zygoma. Ligarnentous fibres are 

 likewise placed across the fissures and intervals left in the cartilage. 



Of the muscles of the pinna, those which are attached by one end to the 

 side of the head, and move the pinoa as a whole, have been already des- 

 cribed (p. 170) : there remain to be examined several smaller muscles, com- 

 posed of thin layers of pale fibres, which extend from one part of the pinna 

 to another, and may be named the special muscles of the organ. Six small 

 muscles are distinguished ; four being placed on the outer and two on the 

 inner or deep surface of the pinna. 



The smaller muscle of the helix (m. minor helicis) is a small bundle of 

 oblique fibres, lying over, and firmly attached to, that portion of the helix 



which springs from the 

 Fig. 497 Fig. 498. bottom of the concha. 



Fig. 497. CARTILAGE OF THE 

 PlNNA EXPOSED, WITH THE 

 MUSCLES ON ITS OUTER SUR- 

 FACE. 



] , musculus helicis minor ; 

 2, m. helicis major ; 3, tra- 

 gicus ; 4, antitragicus. 



Fig. 498. INNER SURFACE OF 

 THE CARTILAGE OF THE 

 PINNA WITH THE SMALL 

 MUSCLES ATTACHED. 



5, transversus auriculse 

 muscle ; 6, obliquus auriculas 

 muscle. 



The greater muscle of the helix (m. major helicis) lies vertically along the 

 anterior margin of the pinna. By its lower end it is attached to the process 

 of the helix j and above, its fibres terminate opposite the point at which the 

 ridge of the helix turns backwards. 



