THE LARYNX. 



1101 



Epiglottis. 



From above the lower border posteriorly, there passes to the cricoid cartilage, 

 in and on each side of the median line, the crico-thyroid membrane, on each side 

 of which is the Crico-thyroid muscle. 



The posterior borders terminate above in the superior cornua, and below in the 

 inferior cornua. The two superior cornua, long and narrow, directed upward, 

 backward, and inward, terminate each in a conical extremity which gives attach- 

 ment to the lateral thyro-hyoid lig- 

 ament. The two inferior cornua 

 are short and thick ; they pass 

 downward, with a slight inclina- 

 tion forward and inward, and pre- 

 sent each on its inner surface a small 

 oval articular facet for articulation 

 with the side of the cricoid carti- 

 lage. On the posterior border are 

 inserted the Stylo-pharyngeus and 

 Palato-pharyngeus muscles. 



The Cricoid Cartilage is so called 

 from its resemblance to a signet- 

 ring (xfjcxo;. a ring). It is smaller, 

 but thicker and stronger than the 

 thyroid cartilage, and forms the 

 lower part of the cavity of the 

 larynx. 



Its anterior half (annulus) is 

 narrow, convex, affording attach- 

 ment at the sides to the Crico- 

 thyroid muscles, and behind to 

 part of the Inferior constrictor. 



Its post :/<<>/ half (lamina) is 

 very broad both from side to side 

 and from above downward : it pre- 

 sents posteriorly in the middle line 

 a vertical ridge (linea eminens) for 

 the attachment of the longitudinal 

 fibres of the oesophagus, and on 

 either side a broad depression (fo- 

 vea) for the Crico-arytenoideus pos- 

 ticus muscle. 



At the point of junction of the 

 two halves of the cartilage on 

 either side is a small round ele- 

 vated facet for articulation with 

 the inferior cornu of the thyroid 

 cartilage. 



The lower border of the cricoid 

 cartilage is horizontal and connected to the upper ring of the trachea by fibrous 

 membrane. 



Its upper border is directed obliquely upward and backward, owing to the 

 height of the lamina. The upper border of the lamina is surmounted on each 

 end by a smooth, oval facet for articulation with the arytenoid cartilage. Between 

 these articular surfaces is a slight notch. To the rest" of the upper border of the 

 entire cartilage, all the way around from one arytenoid facet to the other, is 

 attached the Crico-thyro-arytenoid ligament, and externally to this, at the sides, 

 the lateral Crico-arytenoid muscle. 



The inner surface of the cricoid cartilage is smooth and lined by mucous 

 membrane. 



Posterior 

 surface. 



Arytenoid cartilages, bate. 



Insertion of 



CRICO-ARYTENOIDEUS 

 POSTICUS ET LATERALIS 



Cricoid. 

 Articular facet for 

 arytenoid cartilage. 



Articular facet for_ _ 

 inferior cornu of 

 thyroid cartilage. 



FIG. TOO. The cartilages of the larynx. Posterior view. 



