74 SURGICAL APPLIED ANATOMY. [Chap. v. 



gangrene from frost-bite. This is due to the fact that 

 all the vessels are superficial and are close beneath the 

 surface, that the part is much exposed to cold, and 

 that the pinna lacks the protection of a covering of 

 fat. The same conditions predispose to gangrene of 

 the nose from external cold. Bloody tumours 

 (hsematomata) are often met with on the pinna, and 

 are said to be more common in lunatics. They 

 appear to be frequently due to injury, and consist of 

 an extravasation between the perichondrium and the 

 cartilage. 



Nerve supply. The outer siirface of the pinna 

 is supplied by the auriculo-temporal nerve, with the 

 exception of the skin over the antitragus, the vertical 

 part of the antihelix, the corresponding part of the 

 helix and its fossa, and the lobule, which parts are 

 all supplied by the great auricular nerve. The inner 

 s\irface is almost entirely supplied by the latter nerve, 

 the small occipital nerve giving a branch to the 

 upper extremity, and Arnold's nerve a branch to the 

 back of the concha, near the mastoid process. The 

 meatus is supplied mainly by the auriculo-temporal, 

 with, in addition, a contribution from Arnold's nerve, 

 which goes to the lower and back part of the canal, 

 not far from its commencement. Arnold's nerve, a 

 little branch from the pneumo-gastric, has been 

 credited with a good deal in connection with the 

 nerve relations of the ear. After a heavy dinner, 

 when the rose-water comes round, it is common to see 

 the more experienced of the diners touch the lower 

 part of the back of the ear with the moistened 

 serviette. This is said to be very refreshing, and is 

 supposed to prove to be an unconscious stimulation of 

 Arnold's nerve, a nerve whose main trunk goes to 

 the stomach. Hence, this little branch has been 

 facetiously termed " the alderman's nerve." 



Ear coughing, ear sneezing, ear yawning 



