160 



DISSECTION OF THE LARYNX. 



Fig. 43. 



marked by a median ridge between two contiguous muscular depressions. 

 On each side, immediately in front of tin 1 square part, is a shallow articu- 

 lar mark, which receives the lower cornu of the thyroid cartilage. The 

 inner surface is smooth, and is covered by mucous membrane. 



The lower border is undulating, and is united to the trachea by fib'rous 

 membrane. The upper border is nearly straight posteriorly, opposite the 



deep part of the ring; and this portion 

 is limited on each side by an articular 

 mark for the arytaenoid cartilage. In 

 front of that spot the border is sloped 

 obliquely downwards to the middle line. 

 At the middle line behind there is a 

 slight excavation in each border. 



The two aryt&noid cartilages, c, arc 

 placed one on each side at the back of 

 the larynx, on the upper border of the 

 cricoid cartilage. Each is pyramidal in 

 shape, is about half an inch in depth, 

 and offers for examination a base and 

 apex, and three surfaces. 



The base has a slightly hollowed sur- 

 face behind for articulation with the 

 cricoid cartilage, and is elongated in 

 front into a process which gives attach- 

 ment to the vocal cord. The apex is 

 directed backwards and somewhat in- 

 wards, and is surmounted by the carti- 

 lage of Santorini. 



The inner surface is narrow, especially 

 above, and flat. The outer is wide and 

 irregular, and on it is a small projection 

 at the base, which receives the insertion 

 of some of the muscles. At the pos- 

 terior aspect the cartilage is concave and 

 smooth. 



Cartilages of Santorini. Attached 

 to the apex of each arytasnoid cartilage 

 is the small, conical fibro-cartilage of 

 Santorini (corniculum capitulum), which 

 is bent inwards towards the one of the 

 opposite side. The arytreno-epiglottidean 

 fold is connected with it. 



Cuneiform cartilages. Two other 

 small fibro-cartilaginous bodies, one on 

 each side, which are contained in the arytceno-epiglottid folds, have 

 received this name. Each is somewhat elongated and rounded in form, 

 like a grain of rice; it is situate obliquely in front of the capitulum of the 

 aryta-noid cartilage, and its place in the fold of the mucous membrane is 

 marked by a slight whitish projection. 



The epiglottis (fig. 43, A ) is single, and is the largest of the pieces of 

 yellow h'bro-cartilage. In form it is cordate, and it resembles a leaf, 

 with the stalk below and the lamina or expanded part above. Its position 

 is behind the tongue, and in front of the orifice of the larynx. During 



HYOID BONE AND THE LARYWGEAL 



CARTILAGES. 



Q. Body of the hyoid bone. 

 H. Large cornu. 

 J. Small cornu. 



A. Epiglottis. 



B. Thyroid cartilage, 

 c. Arytsenoid cartilage. 



D. Cricoid cartilage. 



E. Upper cornu, and 



F. Lower cornu of the thyroid carti- 



lage. 



