280 THE LAEYXX. 



THE LARYNX, OR ORGAN OF VOICE. 



The larynx is placed at the upper and fore part of the neck, where 

 it forms a considerable prominence in the middle line. It lies between 

 the large yessels of the neck, and below the tongue and os hjoides, 

 to which bone it is suspended. It is covered in front by the cervical 

 fascia along the middle line, and on each side by the sterno-hyoid, 

 sterno-thyroid, and thyro-hyoid muscles, by the npper end of the thyroid 

 body, and by a small part of the inferior constrictor of the phar^-nx. 

 Behind, it is covered by the pharyngeal mucous membrane, and above 

 it opens into the cavity of the pharynx. 



The larynx consists of a framework of cartilages, articulated together, 

 and connected by ligaments, two of which, named the true vocal conh, 

 are more immediately concerned in the production of the voice. It 

 also possesses muscles, which move the cartilages one upon another, 

 and modify the form and tension of its apertures, a mucous membrane 

 lining it internally, numerous mucous glands, and, lastly, blood-vessels, 

 lymphatics, and nerves, besides areolar tissue and fat. 



CARTILAGES OF THE LARYNX 



The cartilages of the larynx (tig. 188) consist of three single and 

 symmetrical pieces, named respectively the ihyroid cartilage (Ji, i), the 

 cricoid cartilage (d), and the cartilage of the epiglottis (/), and of six 

 others, which occur in pairs, namely, the two arytenoid cartilages (a, a), 

 the corninila largngis, and the cuneiform cartilages. In all there are 

 nine distinct pieces, but the cornicula and cuneiform cartilages are very 

 small. Only the thyroid and cricoid cartilages are seen on the front 

 and sides of the larynx ; the arytenoid cartilages, surmounted by the 

 cornicula laryngis, together with the back of the cricoid cartilage, on 

 which they rest, form the posterior wall of the larynx, whilst the 

 epiglottis is situated in front of, and the cuneiform cartilages on each 

 side of the upper opening. 



The thyroid cartilage, the largest, consists of two flat lateral plates 

 which are continuous in front, forming a narrow angle with one another 

 like the letter V, most prominent at the upper part. This angular pro- 

 jection is subcutaneous, and is much more marked in the male than in 

 the female, being named in the former the pomum Adami. The two 

 symmetrical halves, nam6d the cdce, are somewhat quadrilateral in form : 

 of each half the anterior border where they are joined is the shortest, 

 the pomum Adami being surmounted by a deep notch (see fig. 180) ; the 

 free posterior border is thickened and vertical, and is prolonged up- 

 wards and downwards into two processes or cornua (fig. 188, I), c) ; it 

 gives attachment to the stylo-pharyngeus and palato-pharyngeus muscles ; 

 the upper and lower border have each a well-marked sinuosity close to 

 the cornu : otherwise the upper is convex, and the lower nearly straight. 

 The flattened externcd surface of each ala is marked by an indistinct ob- 

 lique hue or ridge (fig. 188, immediately below e), which, commencing at 

 a tubercle, situated at the back part of the upper border, passes down- 

 wards and forwards, so as to mark off the anterior three-fourths of the 

 surface from the remainder. This line gives attachment below to the 

 sterno-hyoid, and above to the thyro-hyoid muscle, whilst the small 

 smooth surface behind it gives origin to part of the inferior constrictor 



