1172 



THE ORGANS OF VOICE AND RESPIRATION 



laterally, by a fold of mucous membrane, enclosing ligamentous and muscular 

 fibres, stretched between the side of the epiglottis and the apex of the arytenoid 

 cartilage; this is the arytenoepiglottic fold (Figs. 884 and 887), on the margin of 

 which the cuneiform cartilage forms a more or less distinct whitish prominence. 

 The superior or false vocal cords (plicae ventriculares) (Figs. 883 and 884)-, so 

 called because they are not directly concerned in the production of the voice, 

 are two thick folds of mucous membrane, each enclosing a very narrow band of 

 connective tissue, the so-called superior thyroarytenoid ligament. This is attached 

 in front to the angle of the thyroid cartilage immediately below the attachment 

 of the epiglottis, and behind to the antero-external surface of the arytenoid carti- 

 lage. The lower border of this ligament, enclosed in mucous membrane, forms a 

 free crescentic margin, which constitutes the upper boundary of the ventricle 

 of the larynx. 



STERNO- 



THYREOIDEUS 



FIG. 885. Muscles of larynx, front view. The Sterno- 

 thyroids and right Thyrohyoid have been removed. 

 (Testut.) 



FIG. 886. Muscles of larynx, from behind. 

 (Testut.) 



The inferior or true vocal cords (plicae vocales) (Figs. 883 and 884), so called 

 from their being concerned in the production of sound, are two strong bands 

 named the inferior thyroarytenoid ligaments. Each ligament consists of a band 

 of yellow elastic tissue, attached in front to the depression between the alse of the 

 thyroid cartilage, and behind to the vocal process at the base of the arytenoicj. 

 Its lower border is continuous with the thin lateral part of the cricothyroid mem- 

 hra,ne L Its upper border forms the lower boundary of the ventricle of the larynx. 

 Externally, the Thyroarytenoideus muscle lies parallel with it. It is covered 

 internally by mucous membrane, which is extremely pale, thin, and closely ad- 

 herent to its surface. The node-like attachment of the ligament to the thyroid 

 cartilage appears as a yellow spot (macula flava); the vocal process also shines 

 through the mucosa as a yellowish spot. 



The ventricle of the larynx or laryngeal sinus (ventriculus laryngis [Morgaanii]) 

 (Figs. 883 and 884Vis an oblong fossa, situated between the superior and inferior 

 voca.1 cords on each side, and extending nearly their entire length. This fossa is 

 bounded, above, by the free crescentic edge of the false vocal cord; below, by the 



