ORGANS OF VOICE AND RESPIRATION 209 



Cuneiform cartilages, or cartilages of Wrisberg, are two 



small cartilages, one on each side, found in the aryteno- 

 epiglottidean fold. 



The epiglottis covers the superior aperture of the larynx ; 

 it is a leaf-shaped lamina of yellow nbro-cartilage. 



Apex: attached to receding angle of thyroid by thyro 

 epiglottic ligament. 



Base : broad, rounded, and free ; directed upwards. 



Anterior surface: covered in upper part by mucous mem- 

 brane, which passes forwards as the three glosso-epiglottic 

 folds to connect it with the tongue ; below it is attached to 

 the hyoid bone by hyo-epiglottic ligament. 



Posterior surface : covered by mucous membrane, concave 

 from side to side, concavo-convex from above downwards; 

 the convex part is known as the cushion or tubercle of the 

 epiglottis. 



The LIGAMENTS of the larynx are : 



The thyro-hyoid membrane : passes from the upper border 

 of the thyroid cartilage to the upper border of the posterior 

 surface of the hyoid bone: between it and the posterior 

 surface of the hyoid bone is a synovial bursa. It is pierced 

 by the superior laryngeal vessels and internal laryngeal nerve 

 of each side. 



(The lateral thyro-hyoid membrane is the posterior edge of 

 the preceding, passes from the superior cornu of the thyroid 

 to the tip of the great cornu of the hyoid bone, in which is 

 found a small cartilaginous nodule, the cartilage triticea.) 



The crico-thyroid membrane connects the thyroid and 

 cricoid cartilages. Consists of two parts : 



Central: thick, triangular, with base down wards, passingfrom 

 lower border of thyroid to upper border of cricoid cartilage. 



Lateral : thinner, passes from upper border of cricoid car- 

 tilage internally to ala of thyroid, ending in a free border, 

 the true vocal cord, or inferior thyro-arytenoid ligament. 



The superior thyro - arytenoid ligaments are attached 

 anteriorly to the angle between the alae of the thyroid 

 cartilage, just below the epiglottis, and posteriorly to the 

 anterior surface of the arytenoid cartilage. They lie within 

 the mucous membrane, forming the false vocal cords. 



The inferior thyro-arytenoid ligaments are attached an- 

 teriorly to the angle between the alae of the thyroid cartilage, 

 and posteriorly to the anterior process at the base of the 

 arytenoid cartilage. The inner free edge, covered with 

 mucous membrane, forms the true vocal cord, and below it is 

 continuous with the lateral part of the crico-thyroid ligament. 



