248 HUMAN ANATOMY. 



The intrinsic ligaments are sixteen in number, as follows : 



Hyo-epiglottic ligament; 



Crico-thyroid membrane ; 



Two crico-thyroid capsular ligaments; 



Two crico-arytenoid ligaments; 



Two crico-arytenoid capsular ligaments; 



Two superior thyro-arytenoid ligaments (in false cords) ; 



Two inferior thyro-arytenoid ligaments (in true cords); 



Thyro-epiglottic ligament; 



Three glosso-epiglottic folds. 



The hyo-epiglottic ligament is a fibro-elastic band, connect- 

 ing the anterior surface of the epiglottis with the upper border 

 of the hyoid bone. The ligaments connecting the cricoid to the 

 thyroid cartilage are three also the crico-thyroid ligament, cap- 

 sular ligaments, and synovial membranes. 



The crico-thyroid membrane, a yellow, elastic band, connects 

 the adjacent margins of the cricoid and thyroid cartilages, and 

 extends from the upper border of the cricoid cartilage to the 

 lower margin of the true vocal cords. 



The two crico-thyroid capsular ligaments surround the ar- 

 ticulations between the inferior horns of the thyroid and the 

 cricoid cartilage. 



The snyovial membrane lines the capsular ligaments, form- 

 ing a true enarthrodial joint. 



The ligaments of the epiglottis are the thyro-epiglottic, the 

 hyo-epiglottic, and the three glosso-epiglottic folds of mucous 

 membrane before described. 



The superior aperture of the larynx is a triangular opening 

 with the apex in front. It is bounded behind by the apices of 

 the arytenoid cartilages and corniculae laryngis, in front by the 

 epiglottis, and laterally by the aryteno-epiglottidean folds. From 

 this, as its superior boundary, the cavity of the larynx extends 

 as low as to the lower border of the cricoid cartilage. The true 

 vocal cords and the thyro-arytenoid muscle divide it into two 

 parts, the narrow fissure between the two cords being called the 

 glottis., or rima glottidis. 



The superior or false vocal cords are two folds of mucous 

 membrane inclosing the superior thyro-arytenoid ligaments. 



The inferior or true vocal cords are two folds of mucous 

 membrane inclosing the inferior thyro-arytenoid ligaments, com- 

 posed of elastic tissue, from the sides of the upper border of the 

 cricoid cartilage, extending upward to the bases of the arytenoid 

 cartilages, and lower portion of the angle of the thyroid. Their 

 upper margins correspond to the lower edges of the ventricles of 

 the larynx. 



