THE LARYNX. 357 



(5) Thyro-arytenoideus. This muscle arises from the angle of 

 the thyroid and the cricothyroid membrane, and is inserted into 

 the arytenoid cartilage. It consists of two portions, or fasciculi : 

 An inner, which is inserted into the vocal process of the arytenoid 

 and is adherent to the true vocal cord ; and an outer portion, 

 which is inserted into the muscular process. The action of the 

 two muscles as a whole is to draw the arytenoid cartilages toward 

 the thyroid, shortening and relaxing the vocal cords ; the inner 

 fasciculus acting alone modifies the elasticity and tension of the 

 vocal cords, while the outer rotates the arytenoid cartilages inward 

 and approximates the cords. 



(6) Thyro-epiglottideus. It arises from the angle of the thyroid 



2 



16 -J 



17 



FIG. 196. The laryugoscopic image in easy breathing: 1, base of the tongue; 2, 

 median glosso-epiglottic ligament ; 3, vallecula ; 4, lateral glosso-epiglottic ligament ; 

 5, epiglottis ; 6. cushion of epiglottis; 7, cornu major of hyoid bone; 8, ventricular 

 band, or false vocal cord ; 9, true vocal cord ; opening of the ventricle of Morgagni 

 seen between 8 and 9; 10, folds of mucous membrane; 11, sinus pyriformis; 12, car- 

 tilage of Wrisberg ; 13, aryteno-epiglottic fold ; 14, rima glottidis ; 15, arytenoid 

 cartilage ; 16, cartilage of Santorini ; 17, posterior wall of pharynx (Stoerk). 



cartilage, and is inserted into the aryteno-epiglottic fold and the 

 margin of the epiglottis. The action of these muscles is to depress 

 the epiglottis, and, by virtue of some of the fibers which spread 

 out upon the outer surface of the sacculus laryngis, to compress it. 



(7) ,Aryteno-epiglottideus Superior. This arises from the apex 

 of the arytenoid, and its fibers disappear in the aryteno-epiglottic 

 fold. The action of the pair is to constrict the opening of the 

 larynx during deglutition. 



(8) Aryteno-epiglottideus Inferior. This muscle also arises 

 from the arytenoid, and spreads out upon the inner surface of the 

 sacculus laryngis, and the action of the pair is to compress the 

 sacculus. 



Gray, to whom we are indebted for the description of the 



