850 



THE ORGANS OF SPECIAL SENSE. 



between the anti-helix arid the cauda helicis. Other less important bands are 

 found on the cranial surface of the pinna. 



The muscles of the pinna (Fig. 456) 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 auriculum (page 301); and 2. The intrinsic, 

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



Helicis major. 

 Helicis minor. 

 Tragic us. 



Antitragicus. 

 Transversus auriculae. 

 Obliquus auriculae. 



The Musculus helicis major is a narrow vertical band of muscular fibres, situated 

 upon the anterior margin of the 

 helix. It arises, below, from the 

 cauda helicis, and is inserted into 

 the anterior border of the helix, 

 just where it is about to curve 

 backward. It is pretty constant in 

 its existence. 



FIG. 455. The pinna, or auricle. 

 Outer surfaces. 



FIG. 456. The muscles of the pinna. 



The Musculus helicis minor is an oblique fasciculus which covers the crus 

 helicis. 



The Tragicus is a short, flattened band of muscular fibres situated upon the 

 outer surface of the tragus, the direction of its fibres being vertical. 



The Antitragicus arises from the outer part of the antitragus : its fibres are 

 inserted into the cauda helicis and antihelix. This muscle is usually very distinct. 



The Transversus auriculae is placed on the cranial surface of the pinna. It 

 consists of scattered fibres, partly tendinous and partly muscular, extending from 

 the convexity of the concha to the prominence corresponding with the groove of the 

 helix. 



The Obliquus auriculae (Tod) consists of a few fibres extending from the upper 

 and back part of the concha to the convexity immediately above it. 



The arteries of the pinna are the posterior auricular from the external carotid, 

 the anterior auricular from the temporal, and an auricular branch from the 

 occipital artery. 



The veins accompany the corresponding arteries. 



The nerves are : the auricularis magnus, from the cervical plexus ; the auricu- 





