70 SURGICAL APPLIED ANATOMY. [Chap. vi. 



be rotated outwards through a quarter of a circle."* 

 This manoeuvre should engage it on the orifice of the 

 tube. 



Blood supply. The tympanum is supplied by 

 the following arteries, the tympanic of the internal 

 maxillary and internal carotid, the petrosal of the 

 middle meningeal, and the stylo-mastoid of the pos- 

 terior auricular. It is the distribution of the main 

 trunk of the last-named vessel that gives some reason 

 for the practice of applying blisters behind the ear in 

 disease located in the deeper parts. The fact that 

 some of the tympanic veins end in the superior petrosal 

 and lateral sinuses, gives another explanation of the 

 frequent occurrence of thromboses of those channels 

 in inflammatory affections of the middle ear. 



The chorda tympani nerve, from its exposed 

 position in the tympanum, is very likely to be damaged 

 in suppurative disease of the middle ear ; and Urban- 

 tschitsch has stated that such disease in this part may 

 be associated with anomalies of taste. 



CHAPTER VI. 



THE NOSE AND NASAL CAVITIES. 



1. THE nose. The skin over the root, and the 

 greater part of the dorsum, of the nose, is thin and lax. 

 Over the abe, however, it is thick, very adherent to 

 the deeper parts, and plentifully supplied with 

 sebaceous and sweat glands. Inflammation of the 

 integuments over the cartilaginous portion of the 

 nose is apt to be very painful, and to be associated 

 with much vascular engorgement. The pain depends 



* Smith and Walsham's " Operative Surgery," p. 12. 2nd ed 1876. 



