NORMAL ANATOMY OF THE LARYNX. 



103 



lengthen the arm of the vertical lever of the 

 arytenoid, and yield to any oblique force 

 directed upon them. 



The cuneiform cartilages, ('Syn. cartilagines 

 cuneiformes, sen WrisbergiuiKEJ) are two small 

 cylindrical cartilaginous bodies, situated im- 

 mediately in front of the vertical prominence 

 of the arytenoid cartilages in the fold of mu- 

 cous membrane g, (jig. 22.) They present a 

 vertical and horizontal prominence in the shape 

 of the letter L, and partake of the form of the 

 arytenoid cartilages. They are not always pre- 

 sent, and their existence in man is denied by 

 Cruveilhier :* this however is an error. Both 

 Cuvierf and WolrTJ have confounded them 

 with the cornicula or cartilages of Santorini. 

 In the Quadrumana they are conspicuous, 

 having the superior vocal ligaments attached to 

 their bases, and they appear afterwards to con- 

 nect them with the arytenoid cartilages. The 

 cuneiform cartilages are sometimes described 

 by Cruveilhier and other writers (though inac- 

 curately) as the arytenoid glands. They serve 

 as a link of connection between the arytenoid 

 cartilages and superior ligaments. 



The epiglottis, from sort, upon, yXwrra, the 

 tongue. Syn. KX^OV, Hipp. Liguln, Gal. 

 Operculum, Cic. || Cartilago epiglottidis. 

 Epiglotte, Fr. Ke/ildeckel, Germ. The epi- 

 glottis is a cartilaginous valve, situated at 

 the base of the tongue, and covering the 

 opening of the larynx. The direction of the 

 epiglottis is vertical, except during the act of 

 deglutition, when it becomes horizontal. In 

 form it has been compared to a cordate leaf, 

 (Jig. 23,) or that of the artichoke. The di- 

 mensions vary with the volume of the larynx. 

 The anterior aspect of the epiglottis is convex, 

 the posterior concave ; it is partly free and 

 partly connected : the free portion projects 

 above the level of the base of the tongue. It 

 is lined by the mucous membrane : the centre 

 of its superior margin is very slightly notched. 

 Inferiorly it terminates by a kind of pedicle, 

 very thin and delicate, which is attached to the 

 angle of the thyroid immediately above the 

 plane of the thyro-arytenoid ligaments. Nu- 

 merous foramina are observed, perforating its 

 substance (f f, Jig. 23), rendering the struc- 

 ture of this cartilage less dense than that of 

 the thyroid or cricoid cartilage. It is consi- 

 dered to be more brittle, in consequence of 

 the cohesion of its particles being affected by 

 these perforations. Its elasticity, however, is 

 augmented by each perforation admitting some 

 fasciculi of the yellow elastic ligament which is 

 expanded, and, as it were, rivetted on its an- 

 terior aspect. In the larger Ruminantia, such 

 as the ox, this structure is very conspicuous, 

 the thickness of the elastic tissue being nearly 

 equal to that of the epiglottis itself. This 

 ligament is disposed so as to secure perma- 

 nently the return of the epiglottis after its de- 



* Anat. Descript. 



t Le9ons Anat. Comp. 



% De organo vocis Majnnaalium. 



In Lib. Morh. 1. 



|| De Nat. Deor. ii. p. 54. 



Fig. 23. 



A posterior angular view of the cartilages of the 

 larynx, exposing the rugged and perforated structure 

 of the epiglottis after the removal of the mucmis 

 membrane and the yellow elastic ligamentous tissues, 

 (Drawn from a preparation in the Museum of 

 King's College, London.} 



a a, the arytenoid cartilages ; 6 b, the superior 

 cornua ; c, the right inferior cornu ; d, the posterior 

 surface of the cricoid catilage; e, the fora men for 

 the transit of the superior laryngeal nerve ; f f, 

 the perforation of the epiglottis ; i, the superior 

 margin of the thyroid \ t, the trachea j h, the right 

 inferior tubercle. 



pression in the act of deglutition, indepen- 

 dently of any muscular fibres. Its perforations 

 have been described as giving lodgement to 

 " muciparous follicles," but their office seems 

 not to have been hitherto thoroughly investi- 

 gated. 



Articulations and ligaments of the larynx. 

 The articulations are divided, first, into those 

 connecting the larynx with surrounding struc- 

 tures, called extrinsic articulations ; and, se- 

 condly, those peculiar to the larynx itself, 

 termed intrinsic articulations. 



Extrinsic articulations. The hyo-thyroid 



