The Throat and the Voice 



277 



now the tongue be forcibly drawn forward, a curved ridge 

 may be seen behind it. This is the epiglottis, which, as 

 we have already learned, shuts down, like the lid of a 

 box, on the top of the larynx (sees. 156 and 246). 



431. The Larynx. The larynx, the essential organ of 

 voice, forms the box-like top of the 



windpipe. It is built of variously 

 shaped cartilages, connected by 

 ligaments. It is clothed on the 

 outside with muscles ; on the inside 

 it is lined with mucous membrane, 

 continuous with that of the other 

 air passages. 



432. The Thyroid Cartilage. The 

 larynx has for a framework two 

 cartilages, the thyroid and the cricoid, 

 one above the other. 



The larger of these, called the 



thyroid, from a supposed resem- 



FIG. 149. View of the Carti- 



blance to a shield, Consists of two lages and Ligaments of the 

 extended wings which join in front Larynx. (Anterior view.) 



but are separated by a wide interval A, hyoid bone; B, thyro-hyoid 



behind. The united edges in front 



project and form the "Adam's 



apple," plainly seen and easily felt 



on most people, especially on very 



lean men. 



Above and from the sides rise 

 two horns which are connected by bands to the hyoid bone, 

 from which the larynx is suspended (sec. 42 and Fig. 45). 



From the underside of the thyroid two horns project 

 downwards to become jointed to the cricoid. The thyroid 

 thus rests upon, and is movable on, the cricoid cartilage. 



membrane; C, thyroid carti- 

 lage; D, crico-thyroid mem- 

 brane ; E, cricoid cartilage, 

 lateral ligaments seen on each 

 side; F, upper ring of the 

 trachea. (" Adam's apple " is 

 in the V-shaped groove on a 

 line with B and C.) 



