158 SURGICAL APPLIED ANATOMY. [Chap. ix. 



even fatal haemorrhage has occurred from these vessels " 

 (Durham). In introducing the cannula it may readily 

 slip between the crico-thyroid membrane and the 

 mucous lining instead of entering the trachea. 



Foreign bodies often find their way into the 

 air passages, and have been represented by articles of 

 food, teeth, pills, buttons, small stones, and the like. 

 They are usually inspired during the act of respiration, 

 and may lodge in the superior apertiire of the larynx, 

 or in the rima, or find their way into the ventricle, 

 or lodge in the trachea, or enter a bronchus. If a 

 foreign substance enters a bronchus it usually selects 

 the right, that bronchus having its aperture more im- 

 mediately under the centre of tlie trachea than has 

 the left tube. Quite recently, in a dissecting-room 

 subject, I found two threepenny pieces lying side by 

 side, in the right bronchus, so as to entirely block the 

 tube. The danger of inhaled foreign substances de- 

 pends not so much upon the mechanical obstruction 

 they offer, as upon the spasm of the glottis they excite 

 by reflex irritation. A body may, however, lodge in the 

 ventricle for some time without causing much trouble, 

 as in a case reported by Desault, where a cherry-stone 

 lodged for two years in this cavity without much 

 inconvenience to its host. In one strange case a 

 bronchial gland found its way into the trachea by 

 producing ulceration of that tube, was coughed up, 

 and became impacted in the rima glottidis. The 

 patient was saved from immediate suffocation by 

 tracheotomy. Foreign bodies have been removed 

 from the right bronchus through a tracheotomy 

 wound. In this way MacCormac removed from the 

 bronchus the blade of a tooth forceps. 



The thyroid body. Each lobe should measure 

 about 2 inches in length, about \\ inches in breadth, 

 and \ of an inch in thickness at its largest part. 

 When distinctly beyond these measurements the 



