CHAPTER XVI. 



VOICE AND SPEECH. 



198. Voice. The organ of voice is the larynx, a modifica- 

 tion of the upper part of the trachea, consisting of a frame- 

 work of cartilages, lined with 

 mucous membrane, and moved 

 on one another by muscles. 



The lowest cartilage of the 

 larynx is called the cricoid car- 

 tilage. It forms a complete 

 ring above the first cartilage of 

 the trachea, and, while narrow 

 in front, rises to a height of 

 more than half an inch 

 behind. 



Above the cricoid, and par- 

 tially embracing it, is the 

 thyroid cartilage. This .carti- 

 lage is open behind, and, at the 

 upper border in front, projects 

 forwards, making the promi- 

 nence called " Adam's apple." 

 In front, its lower border is a Fi 133 ._ CABTILAGES O r THE 

 little above the cricoid, and the LARYNX, from behind, a, 

 space thus left is filled up with 

 elastic tissue, the crico-thyroid 

 membrane; but at the sides its 

 depth increases, and it sends 

 upwards and downwards two 

 pairs of cornua; the inferior 

 cornua articulating with the 

 sides of the cricoid cartilage, so as to furnish a centre of 



Hyoid bone ; 5, lateral thyro- 

 hyoid ligament ; c, thyroid 

 cartilage; d, cricoid; e, ary- 

 tenoid cartilage, surmounted 

 by cartilage of Santorini; /, 

 epiglottis ; g, aperture of 

 glottis, with vocal cord on 

 each side. 



