914 THE RESPIRATORY SYSTEM. 
elastic band, somewhat broken up by adipose tissue, which connects the anterior 
face of the epiglottis to the upper border of the hyoid bone. The thyro-epiglottidean 
ligament (ligamentum thyreoepiglotticum) is strong and thick (Fig. 614, p. 910). 
Composed mainly of elastic tissue, it proceeds downwards from the lower pointed 
extremity of the epiglottis, and is attached to the angular depression between the 
two alze of the thyroid cartilage below and behind the median notch. 
A triangular interval is left between the anterior face of the epiglottis and the 
thyro-hyoid membrane. This is imperfectly closed above by the hyo-epiglottidean 
ligament, and contains a pad of soft fat (Fig. 618, p. 916). 
INTERIOR OF THE LARYNX. 
The cavity of the larynx is smaller than might be expected from an inspection 
of its exterior. On looking into its interior through the superior aperture it 1s 
seen to be subdivided into three portions by two elevated folds of mucous mem- 
brane which extend from before backwards, and project inwards from each side-wall 
of the cavity. The upper pair of folds are the false vocal cords; the lower, more 
definite pair, are the true vocal cords. The latter are the chief agents in the pro- 
duction of the voice, and the larynx is so constructed that changes in their relative 
position and in their degree of tension are brought about by the action of the 
muscles and the recoil of the elastic hgaments. 
Superior Aperture of the Larynx (aditus laryngis)—This is a large obliquely- 
placed opening which slopes rapidly from above downwards and backwards. Some- 
what triangular in outline, 
the basal part of the aper- 
bidity ; 
Ws tM ||) 
Base of \ 
is Middle glosso- ture, placed above and in 
tongue —— 
eee cae front, is formed by the free 
| border of the epiglottis. 
ae Vallecula Behind, the opening rapidly 
Lateral glosso- narrows, and finally ends 
an 
( 
\ 
) 
\ pple ea in the interval between the 
1 — Bpiglottis two arytenoid cartilages. 
The sides of the aperture 
are formed by two sharp 
Aryteno- , ; ae Oa 
ceilothdean toa and, prominent olds) jor 
Laryngeal sinus mucous membrane called 
.- Cushion of epiglottis 
Hyoid bone (2 
True vocal 
cord 
False vocal cord the  aryteno - epiglottidean 
Rima |: ee iS, Se 
glottidis— jj 4 __ Cuneiform tubercle folds (plicze ary epiglottice), 
Pyriform_| | which stretch between the 
sinus : Tubercle of aay We ite > c 
Superior & Santon late al inargins of the epi- 
cone glottis in front and the- 
\\ 
thyroid ‘ j 5 
Posterior aspect of arytenoid cartilages behind. 
ricoid cartilage : 
Acbweacthe The aryteno-epiglot- 
tidean folds enclose between 
the two layers of mucous 
membrane which compose 
Fic. 616.—SUPERIOR APERTURE OF LARYNX, exposed by laying open them some connective 
the pharynx from behind. 
Pharyngea] —_ 
wall (cut) 
tissue, muscular fibres be- 
longing to the aryteno-epiglottidean muscles, and in their posterior parts the 
cuneiform cartilages and the cornicula laryngis which surmount the arytenoid 
cartilages. These small nodules of cartilage raise the hinder part of the aryteno- 
epiglottidean fold in the form of two rounded eminences, termed respectively the 
cuneiform tubercle (tuberculum cuneiforme) and the tubercle of Santorini (tuberculum 
corniculatum). 
On either side of the posterior part of the laryngeal opening there is, in the 
pharynx, a small downwardly-directed recess which presents a wide entrance, but 
rapidly narrows towards the bottom. It is termed the sinus pyriformis, and it 1s 
important to the surgeon, because foreign bodies introduced into the pharynx are 
liable to be caught in this little pocket. On the inner side the sinus pyriformis 1s 
