478 



VOICE AND SPEECH. 



cricoid cartilage ; (a) the two arytenoid cartilages ; and the 

 two true vocal cords (A, cv, Fig. 172). The epiglottis (Fig. 

 170, e) has but little to do with the voice, and is chiefly 

 useful in falling down as a " lid " over the upper part of the 

 larynx, to prevent the entrance of food and drink in deglutition. 

 The false vocal cords (cvs, Fig. 172), and the ventricle of the 

 larynx, which is a space between the false and the true cord 

 of either side, need be here only referred to. 



The thyroid cartilage (Fig. 170, 1 to 4) does not form a 

 complete ring around the larynx, but only covers the front 

 portion. The cricoid cartilage (Fig. 170, 5, 6), on the other 

 hand, is a complete ring ; the back part of the ring being much 

 broader than the front. On the top of this broad portion of 

 the cricoid are the arytenoid cartilages (Fig. 169, a) the con- 

 nection between the cricoid below and arytenoid cartilages 

 above being a joint with sy no vial membrane and ligaments, 

 the latter permitting tolerably free motion between them. 



But, although the arytenoid carti- 

 FlG 170 lages can move on the cricoid, they 



of course accompany the latter in 

 all their movements, just as the 

 head may nod or turn on the top 

 of the spinal column, but must ac- 

 company it in all its movements as 

 a whole. 



The thyroid cartilage is also con- 

 nected with the cricoid, not only 

 by ligaments, but by two joints with 

 synovial membrane (if, Figs. 168 

 and 169) ; the lower cortma of the 

 thyroid clasping, or nipping, as it 

 were, the cricoid between them, but 

 not so tightly but that the thyroid 

 can revolve, within a certain range, 

 around an axis passing transversely 

 through the two joints at which the 

 cricoid is clasped. The vocal cords 

 are attached (behind) to the front 

 portion of the base of the arytenoid 

 cartilages, and (in front) to the re- 

 entering angle at the back part of 

 the thyroid; it is evident, therefore, 

 that all movements of either of 

 these cartilages must produce an 

 effect on them of some kind or other. 

 Inasmuch, too, as the arytenoid car- 



Cartilages of the larynx seen 

 from before. %. 1 to 4, thyroid 

 cartilage ; 1, vertical ridge or po- 

 mum Adami ; 2, right ala ; 3, 

 superior, and 4, inferior cornu of 

 the right side ; 5, 6, cricoid carti- 

 lage; 5, inside of the posterior 

 part; 6, anterior narrow part of 

 the ring ; 7, arytenoid cartilages. 



