316 



THE LARYNX, LUNGS, VOCAL SACS, ETC. 



E 



The anterior and posterior borders are not parallel but are each 



concave (Fig. 202 V\ 



Fig. 206. The anterior border is thin, 



the posterior thick and rounded. 

 Seen from in front (Fig 1 . 206), 

 the opening between the cords 

 (Rima glotlidis) is slightly wider 

 at each end than in the middle. 

 The ends of the concave poste- 

 rior border are prolonged back- 

 wards and enclosed in a fold of 

 mucous membrane. Part of the 

 tissue enclosed is unstriated mus- 

 cular fibre, which may be traced 

 to the cricoid cartilage. 



(2) [The false vocal cords 

 (Figs. 202 and 206 FJ are simply 

 folds of mucous membrane, 

 which extend vertically on each 

 side of the larynx behind the 

 true vocal cords; they do not 

 extend so far towards the me- 

 dian plane as do the true vocal 

 cords.] 



(3) [Theyentricles of the 

 larynx (Figs. 202 and 206) are 

 two on each side. The anterior 

 ventricles are between the true 



vocal cords and the arytenoid cartilages ; they are open anteriorly, 

 and closed by mucous membrane posteriorly. 



The posterior ventricles open towards the median plane, each 

 presenting an oval opening (Fig. 202), which widens outwards into 

 a large cavity (Fig. 206 //). The cavity is bounded in front by 

 the base of the true vocal cord, and the mucous membrane attached 

 to it ; posteriorly by the false vocal cord, and externally by the 

 cricoid cartilage and the connective-tissue capsule of the larynx.] 



(4) [The mucous membrane of the larynx varies in struc- 

 ture in various parts of the organ. From the anterior opening 

 of the larynx to the posterior borders of the vocal cords it is 

 lined with stratified epithelium, which is firmly attached to the 

 underlying structures by a small amount of sub-epithelial 



Three sections through the larynx of liana 



esculenta. G. H. 

 I. Sagittal section near the median plane 



through the larynx. 



II. Oblique transverse section through larynx. 

 III. Almost horizontal section through larynx. 

 A Arytenoid cartilage. 

 C Cricoid cartilage. 

 \ Epiglottis. 

 - F False vocal cords. 

 - G Epiglotidean glands. 

 -f/ Hyoid. 

 M Membranous floor of the larynx, cut 



obliquely. 



Opening into root of lung. 

 P Pre-arytenoid cartilage. 

 V Vocal cord. 



