THE VOICE 



223 



thyroid and cricoid cartilages have already been described (see 

 p. 140). 



The highest (posterior) portion of the cricoid is surmounted 

 by two pyramidal cartilages called the arytenoid cartilages. 

 These form movable joints with the cricoid, to which they are 

 held by ligaments. They must also necessarily accompany the 

 cricoid cartilage in all its movements. 



The arytenoid cartilages are connected with the interior surface 

 of the front part of the thyroid cartilage by means of two bands of 



Fig. 214. Back view of the Larynx. 



, thyroid ; 2, cricoid ; 3, arytenoid cartilages ; 

 4, upper ring of the trachea ; 5, ligaments ; 6, epi- 

 glottis. 



Fig. 215. Side view of the 

 Larynx. 



i, hyoid bone ; 2, thyroid ; 3, cricoid- 

 anterior part ; 4, crico - thyroid 

 muscle ; 5, crico-arytenoid muscle. 



elastic fibres which are imbedded in folds of mucous membrane. 

 These fibres form the so-called vocal cords. They are both at- 

 tached to the thyroid cartilage close to the middle line, and con- 

 sequently, when they are stretched, their edges are brought nearly 

 parallel, so that only a thin slit is left for the air to pass between 

 them. 



The epiglottis has nothing to do with the production of sound. 

 It is a cartilaginous lid, the lower and narrower portion of which 

 is fastened by elastic bands to the front part of the thyroid carti- 



