THE LARYNX. 



609 



the connection between the cricoid below and arytenoid car- 

 tilages above being a joint with synovial membrane and liga- 

 ments, the latter permitting tolerably free motion between 



Fig. 163.' 



them. But, although the aryte- 

 noid cartilages 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 accompany 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 (', figs. 

 161 and 162) ; the lower cornua 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-enter- 

 ing 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 cartilages rest on the top 

 of the back portion of the cricoid cartilage (0, fig. 162), 

 and are connected with it by capsular and other ligaments, 

 all movements of the cricoid cartilage must move the 



* Fig. 163. Cartilages of the larynx seen from before. -| I to 4, 

 thyroid cartilage ; I, vertical ridge or pomura Adaini; 2, light ala; 3, 

 superior, and 4, inferior cornu of the right side ; 5, 6, cricoid cartilage ; 

 5, inside of the posterior part ; 6, anterior narrow part of the ring ; 7, 

 arytenoid cartilages. 



R E, 



