770 



ORGANS OF VOICE AND RESPIRATION. 



Fig. 423. The Cartilages of the Larynx. 

 Posterior View. 



EPIGLOTTIS 



The posterior borders, thick and rounded, terminate, above, in the superior 

 cornua ; and, below, in the inferior cornua. The two superior cornua are long 

 and narrow, directed backwards, upwards, and inwards; and terminate in a 

 conical extremity, which gives attachment to the thyro-hyoid ligament. The 



two inferior cornua are short and 

 thick ; they pass forwards and in- 

 wards, and present, on their inner 

 surfaces, a small, oval, articular 

 facet for articulation with the side 

 of the cricoid cartilage. The pos- 

 terior border receives the insertion 

 of the Stylo-pharyngeus and Pa- 

 lato-pharyngeus muscles on each 

 side. 



The Cricoid Cartilage is so called 

 from its resemblance to a signet 

 ring (xptxo?, a ring}. It is smaller 

 but thicker and stronger than the 

 thyroid cartilage, and forms the 

 lower and back part of the cavity 

 of the larynx. 



Its anterior half is narrow, con- 

 vex, affording attachment in front 

 and at the sides to the Crico-thy- 

 roid muscles, and, behind those, to 

 part of the Inferior Constrictor. 



Its posterior half is very broad, 

 both from side to side and from 

 above downwards ; it presents in 

 the middle line a vertical ridge for 

 the attachment of the longitudinal 

 fibres of the oesophagus; and on 

 either side a broad depression for 

 the Crico-arytaenoideus Posticus 

 muscle. 



At the point of junction of the 



THYROID 



ARYTENOlD 



MTICl.M UkTMAU* 



Arytenoid Cart'."* V<a 



Articular ft 

 f fnftr.Co-mu 

 f Thyroid ff. 



two halves of the cartilage on 

 either side, is a small round ele- 

 vation, for articulation with the 

 inferior cornu of the thyroid carti- 

 lage. 



The lower border of the cricoid 

 cartilage is horizontal, and con- 

 nected to the upper ring of the 

 B trachea by fibrous membrane. 



Its upper border is directed ob- 

 liquely upwards and backwards, owing to the great depth of its posterior sur- 

 face. It gives attachment, in front, to the crico-thyroid membrane ; at the sides, 

 to part of the same membrane and to the lateral Crico-arytenoid muscle ; be- 

 hind, the highest point of the upper border is surmounted on each side by a 

 smooth oval surface, for articulation with the arytenoid cartilage. Between 

 the articular surfaces is a slight notch, for the attachment of part of the Ary- 

 taenoideus muscle. 



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

 membrane. 



The Arytenoid Cartilages are so called from the resemblance they bear, when 

 approximated, to the mouth of a pitcher (dpurou-o, a pitcher). They are two in 



