chap, ix.] THE LARYNX AND TRACHEA. 133 



long while the lining of the larynx tends to become 

 dry, on account of the large amount of cold air that 

 is drawn in directly through the mouth. To still keep 

 these parts moist the mucous glands have to exhibit 

 increased energy, and in those who speak much in 

 public the glands may in time become so over-worked 

 as to inflame. It is the inflammation of these glands 

 that constitutes the present affection. The glands are 

 not distributed equally over all parts of the larynx, 

 but are most numerous in the membrane covering 

 the arytenoid cartilages and parts immediately about 

 them, the base of the epiglottis, and the interior of 

 the ventricle. It is in these parts, therefore, that the 

 changes in chronic glandular laryngitis, or dysphonia 

 clericorum, are most marked. 



The entire larynx has been removed for carcino- 

 matous disease, but the operation, although not imme- 

 diately fatal, has not been followed by very satisfactory 

 results. It is removed through an incision in the 

 middle line, and has to be freed from those muscles 

 that lie in front of it (sterno-hyoid, omo-hyoid), as well 

 as from those that are attached to it (sterno-thyroid, 

 thyro-hyoid, inferior constrictor and stylo-pharyngeus). 

 The larynx is then separated from the trachea, and 

 is dissected off from below up. The only vessels of 

 any magnitude divided are the superior and inferior 

 thyroid arteries and the thyroid veins. Both laryngeal 

 nerves are cut. In separating the gullet and pharynx 

 there is great risk of " button - holing " the former 

 tube. 



Tracheotomy and laryngotomy. The trachea 

 is about four and a half inches in length, and from 

 three-quarters to one inch in its extreme width. 

 It is surrounded by an atmosphere of very lax con- 

 nective tissue, which allows a considerable degree 

 of mobility to the tube. The mobility of the 

 trachea is greater in children than in adults, and 



