486 CARTILAGES OF THE LARVNX. 



acute ; in the female, and before puberty in the male, it is obtuse. Where 

 the pomum Adami is prominent, a bursa mucosa is often found between 

 it and the skin. 



Each ala is quadrilateral in shape, and forms a rounded border poste- 

 riorly, which terminates above, in the superior cornu, and below, in the 

 inferior cornu. Upon the side of the ala is an oblique line, or ridge, di- 

 rected downwards and forwards, and bounded at each extremity by a 

 tubercle. Into this line the sterno-thyroid muscle is inserted ; and from it 

 the thyro-hyoid and inferior constrictor take their origin. In the receding 

 angle, formed by the meeting of the tw r o alse upon the inner side of the 

 cartilage, and near its lower border, are attached the epiglottis, the chordae 

 vocales, the thyro-arytenoid, and thyro-epiglottidean muscles. 



The Cricoid (XP/XO? sT5os, like a ring) is a ring of cartilage, narrow in 

 front, and broad behind, where it is surmounted by two rounded surfaces, 

 which articulate with the arytenoid cartilages. At the middle line, poste- 

 riorly, is a vertical ridge which gives attachment to the oesophagus, and 

 on each side of the ridge are the depressions which lodge the crico-aryte- 

 noidei postici muscles. On either side of the ring is a glenoid cavity, 

 which articulates with the inferior cornu of the thyroid cartilage. 



The Jirytenoid cartilages (a^ura/va,* a pitcher), two in number, are tri- 

 angular and prismoid in form. They are broad and thick below where 

 they articulate with the upper border of the cricoid cartilage ; pointed 

 above, and prolonged by tw r o small pyriform cartilages, cornicula laryngis 

 (capitula Santorini), which are curved imvards and backwards, and they 

 each present three surfaces, anterior, posterior, and internal. The poste- 

 rior surface is concave, and lodges part of the arytenoideus muscle ; the 

 internal surface is smoothfand forms part of the lateral wall of the larynx ; 

 the anterior or external surface is rough and irregular, and gives attach- 

 ment to the chorda vocalis, thyro-arytenoideus, crico-arytenoideus lateralis 

 and posticus, and, above these, to the base of the cuneiform cartilage. 



The Cuneiform cartilages are two small cylinders of fibro- cartilage, 

 about seven lines in length, and enlarged at each extremity. By the lower 

 end, or base, the cartilage is attached to the middle of the external surface 

 of the arytenoid, and by its upper extremity forms a prominence in the 

 border of the aryteno-epiglottidean fold of membrane. They are some- 

 times wanting. 



In the male, the cartilages of the larynx are more OF less ossified, par- 

 ticularly in old age. 



The Epiglottis (S-TTJ^XWTT/V, upon the tongue) is a fibro-cartilage of a 

 yellowish colour, studded with a number of small mucous glands, which 

 are lodged in shallow pits upon its surface. It is shaped like a cordate 

 leaf, and is placed immediately in front of the opening of the larynx, which 

 it closes completely when the larynx is draw r n up beneath the base of the 

 tongue. It is attached by its point to the receding angle, between the two 

 alae of the thyroid cartilage. 



Ligaments. The Ligaments of the larynx are numerous, and may be 

 arranged into four groups : 1. Those which articulate the thyroid with the 

 os hyoides. 2. Those which connect it with the cricoid. 3. Ligaments 

 of the arytenoid cartilages. 4. Ligaments of the epiglottis. 



* This derivation has reference to the appearance of both cartilages taken together 

 .nd covered by mucous membrane. In animals, which were the principal subjects of 

 dissection among the ancients, the opening of the larynx with the arytenoid cartilafl 

 bears a striking resemblance to the mouth of a pitcher having a large spout. 



