THE VOICE. 



821 



ferior opening corresponds to the inferior border of the cricoid cartilage. 

 Between these points is the cavity of the larynx, which has stretching across 

 its sides the vocal cords. The vocal cords consist of two pairs ; the supe- 

 rior or false vocal cords are membrano-ligamentous bands, which extend 

 from the receding angle of the thyroid to the external surfaces of the ary- 

 tenoid cartilages ; the inferior or true vocal cords (chorda vocales) are mem- 

 brano-ligamentous bands which stretch across the cavity of the larynx from 

 the receding angle of the thyroid to the processus vocales of the arytenoid 

 cartilages. & Between the borders of the true and false vocal cords is an 

 elliptical opening, the ventricle, which leads to a space running upward and 

 behind the false vocal cords, called the sacculus laryngis. The mucous 



FIG. 205. 



FIG. 206. 



FIG. 207. 



FIG. 205. View of the Larynx and part of the Trachea from Behind with the Muscles Dissected 

 h, the body of the hyoid bone ; e, epiglottis ; t, the posterior borders of the thyroid cartilage ; c, the 

 median ridge of the cricoid ; a, upper part of the arytenoid ; s, placed on one of the oblique fasci- 

 culi of the arytenoid muscle ; b, left posterior crico-arytenoid muscle ; ends of the incomplete car- 

 tilaginous rings of the trachea; I, fibrous membrane crossing the back of the trachea; n, muscular 

 fibres exposed in a part. (From Quain's Anatomy.) 



FIG. 206. View of the Larynx from Above. 1, aperture of glottis ; 2, arytenoid cartilages ; 3, 

 vocal cords ; 4, posterior crico-arytenoid muscles ; 5, lateral crico-arytenoid muscle of right side, 

 that of left side removed ; 6, arytenoid muscle ; 7, thyro-arytenoid muscle of left side, that of right 

 side removed ; 8, thyroid cartilage ; 9, cricoid cartilage ; 13, posterior crico-arytenoid ligament. With 

 the exception of the arytenoid muscle, this diagram is a copy from Mr. Willis's figure. 



FIG. 207. View of the Upper Part of the Larynx as seen by means of the Laryngoscope during 

 the Utterance of a Grave Note, c, epiglottis ; s, cartilages of Santorini ; a, arytenoid cartilages; 

 z, base of the tongue ; ph, posterior wall of the pharynx. 



membrane lining this sac contains a great number of follicular glands 

 which discharge a mucous secretion for the purpose of lubricating the true 

 vocal cords. 



Between the true vocal cords is an opening which is called the rima glot- 

 tidis. The form of the glottis varies very much both in the inspiratory and 

 expiratory acts, and in the act of phonation. 



755. The muscles of the larynx are divided anatomically into the in- 

 trinsic and extrinsic. The former are nine in number, four of them being 



