XV 



SPECIAL USES OF MUSCLES 



213 



effort so as to give the countenance a pleasant ap- 

 pearance. 



150. The Larynx and its Use. In studying the air 

 passages we learned something about this organ, called 

 the voice box. The larynx is' made up of nine separate 

 pieces of cartilage held together by connective tissue 

 and a number of delicate muscles. At the lower end 



fpigloUfs 



FIG. 114. The larynx, top view (Zuppke) : A and a, the vocal cords in resting 

 position ; B and b, the vocal cords in position for producing voice. 



the larynx is attached to the trachea by means of the 

 large cricoid cartilage which has the shape of a signet 

 ring. Above this is placed the large, irregular-shaped 

 thyroid cartilage which forms the projection known as 

 Adam's apple. The opening at the top of the larynx 

 is guarded by a covering of cartilage fixed to the top of 

 the thyroid ; this is the epiglottis. Besides these three 

 large single cartilages, the larynx has three pairs of 

 smaller ones attached to the cricoid. 



