MUSCLES, VESSELS, AND NERVES OF THE EAR. 451 



The Ligaments of the external ear are those which attach the 

 pinna to the side of the head, viz. the anterior, posterior, and liga- 

 ment of the tragus ; and those of the fibro-cartilage, which serve 

 to preserve its folds and connect the opposite margins of the fissures. 

 The latter are two in number, the ligament between the concha 

 and the processus caudatus, and the broad ligament which extends 

 from the .upper margin of the fibro-cartilage of the tragus to the 

 helix, and completes the meatus. 



The proper Muscles of the Pinna are the 



Major helicis, 

 Minor helicis, 

 Tragicus, 

 Antitragicus, 

 Transversus auricula?. 



The Major helicis is a narrow band of muscular fibres situated 

 upon the anterior border of the helix, just above the tragus. 



The Minor helicis is placed upon the posterior border of the 

 helix, at its commencement, in the fossa of the concha. 



The Tragicus is a thin quadrilateral layer of muscular fibres, 

 situated upon the tragus. 



The Antitragicus arises from the antitragus, and is inserted into 

 the posterior extremity, or processes caudatus of the helix. 



The Transversus auricula, partly tendinous and partly muscular, 

 extends transversely from the convexity of the concha to that of the 

 helix, on the posterior surface of the pinna. 



These muscles are rudimentary in the human ear, and deserve 

 only the title of muscles in the ears of animals. Two other muscles 

 are described by Mr. Tod,* the obliquus auris and contractor meatus, 

 or trago-helicus. 



The Meatus auditorius is a canal, partly cartilaginous and partly 

 osseous, about an inch in length, which extends inwards and a little 

 forwards from the concha to the tympanum. It is narrower in the 

 middle than at each extremity, forms an oval cylinder, the long 

 diameter being vertical, and is slightly curved upon itself, the con- 

 cavity looking downwards. 



It is lined by an extremely thin pouch of cuticle, which, when 

 withdrawn after maceration, preserves the form of the meatus. 

 Some stiff short hairs are also found in its interior, which stretch 

 across the tube, and prevent the ingress of insects and dust. Be- 

 neath the cuticle are a number of small ceruminous follicles, which 

 secrete the wax of the ear. > 



Vessels and Nerves. The pinna is plentifully supplied with arte- 

 ries ; by the anterior auricular from the temporal, and by the pos- 

 terior auricular from the external carotid. 



Its Nerves are derived from the auricular branch of the fifth, and 

 from the auricularis magnus of the cervical plexus. 



* "The Anatomy and Physiology of the Organ of Hearing," by David Tod, 1832. 



