INTERIOR OF THE LAEYXX. 



285 



crico-arytenoid ligament on each side, arising from the cricoid, and 

 inserted into the inner and back part of the base of tlie arytenoid 

 cartilage. 



The summits of the arytenoid cartihages and the cornicuhi laryngis 

 have usually a fibrous and synovial capsule to connect them, but"^it"is 

 frequently indistinct. 



INTEEIOR OF THE liARTNX 



The cavity of the larynx is divided into an upper and a lower com- 

 partment by the comparatively 

 narrow aperture of the glottis, or 

 rimaglottiiUs, the margins of which, 

 in their two anterior thirds, are 

 formed by the lower or tnie vocal 

 cords; and the wdiole laryngeal 

 cavity, viewed in transverse verti- 

 cal section (fig. 190), thus presents 

 the appearance of an hour-glass, 

 or of two funnels meeting together 

 by their narrow ends. The upper 

 compartment communicates with 

 the pharynx by the superior aper- 

 ture of the larynx, and contain 

 immediately above the rima glot 

 tidis the ventricles {s) and the 

 upper or false vocal cords. The 

 lower compartment passes inferi- 

 orly into the tube of the windpipe 

 without any marked constriction 

 or limitation between them. The 

 whole of the interior of tiie larynx 

 is lined by mucous membrane. 



The superior aperture of the 

 larynx, by which it communicates 

 with the pharynx, is a triangular 

 opening, wide in front and narrow 

 behind, the lateral margins of 

 which slope obliquely downwards 

 and backwards. It is bounded in 

 front by the e])iglottis (fig. 191, A, 

 e, and fig. 192, a), behind by the 

 summits of the arytenoid carti- 

 lages (fig. 191, B, a) and cornicula 

 laryngis {$) with the angular border 

 of mucous membrane crossing the 

 median space between them, and 

 on the sides by two folds of mu- 

 cous membrane, the ctri/le/w-epi- 

 glottidean folds, which, enclosing a 

 few ligamentous and muscular 



Fig. 190. — Anterior Half of a Trans- 

 verse Vertical Section through the 

 Larynx near its middle (Allen Thomson). 



1, upi^er division of the laryngeal cavity ; 

 2, central portion ; 3, lower dinsion, 

 continued into 4, part of the trachea ; 

 c, the free part of the epiglottis ; e', 

 its cushion ; h, the divided great cornua 

 of the hyoid bone ; ht, thyro-hyoid mem- 

 Lrane ; t, cut surface of the divided thyroid 

 cartilage ; c, that of the cricoid cartilage ; 

 r, first ring of the trachea ; ta, thyro-aryte- 

 uoid muscle ; iil, thyro-arytenoid ligament 

 in the true vocal cord covered by mucous 

 membrane at the rima glottidis : s, the 

 ventricle ; above this, the superior or false 

 cords ; s', the sacculus or pouch opened on 

 the right side. 



fibres and the cartilages of Wris- 



berg, pass forwards from the tips of the arytenoid cartilaf^-es and 



