THE VOCAL COEDS. 



2«7 



is situated on a leyel with the lowr i^art of the arytenoid cartilages, 

 and is bounded by the Irve vocal cords. Above the glottis, another pair 

 of projecting folds is seen, the superior or false vocal cords, which are 

 nuich thinne"r and weaker and less projecting than the inferior, and are 



Fig. 192.— Perspective Yiwx of the Yiz- ]^2. 



Pharyngeal Opening into the La- 

 rynx FROM ABOVE AND BEHIND (,Allen 



Tliomson. ) 



The superior aperture has been much 

 dilated ; the glottis is in a moderately 

 dilated condition ; the wall of the pha- 

 rynx is opened from behind and turned 

 to the sides. 1, body of the hj'oid 

 bone ; 2, small cornua ; 3, great cornua; 

 4, npjjer and lower cornua of the thyroid 

 cartilage ; 5, membrane of the pharynx 

 covering the posterior surface of the 

 cricoid cartilage ; 6, upper part of the 

 gullet ; 7, membranous jxart of the 

 trachea ; 8, projection caused by the 

 cartilage of Santorini ; 9, the same be- 

 longing to the cartilage of Wrisberg ; 10, 

 aryteno-epiglottidean fold ; 11, cut mar- 

 gin of the wall of the pharynx ; «, free 

 part of the epiglottis ; a', its lower 

 pointed jiart ; «", the cushion ; b, 

 eminence on each side over the sacculus 

 or jiouch of the larynx ; h', the ventricles ; 

 c, the glottis : the lines on each side 

 point to the vocal cords. 



arched in form. Bounded by 

 the superior and inferior vocal 

 cords are two deep oval depres- 

 sions, one on each side of the 

 glottis, named the sinuses, or 

 ventricles, of the larynx (fig. 

 190, s, and fig. 192, h') ; and 

 leading upwards from the an- 

 terior parts of these depressions, external to the superior vocal cords, 

 are two small culs-de-sac, named the laryngeal 2^ouches ox saccuU {fig, 

 190, s'). 



The superior vocal cords, also called the false vocal cords, because 

 they are not immediately concerned in the production of the voice, 

 form on each side a free ci-escentic margin, bounding the corresponding- 

 ventricle of the larynx, the hollow of which is seen on looking down 

 into the laryngeal cavity, the superior vocal cords {cvs, fig. 191) being: 

 further apart than the inferior. 



The inferior or true vocal cords, the structures by the vibration 

 of which the sounds of the voice, are produced, bound the two anterior 

 thirds of the aperture of the glottis (fig. 192, c). The mucous mem- 

 brane covering them is so thin and closely adherent as to show the 

 yellowish colour of the ligaments through it. Their free edges, which are 

 sharp and straight, and directed upwards, form the lower boundaries of 

 the ventricles, and are the parts thrown into vibration during the j^ro- 

 duction of the voice. Their inner surfaces are flattened, and look 

 towards each other. 



