DISSECTION OF THE LARYNX. 



231 



The Cricoid Cartilage has the form of a finger ring, from which 

 it receives its name. The depth of the ring is greatest behind, 

 where it presents a portion comparable to the bezel, or part of a ring 

 in which the stone is set. The inner surface of the ring is smooth, 

 and lined by the laryngeal mucous membrane. The outer surface of 

 the bezel is divided by a vertical median ridge which increases the 

 surface of origin of the posterior crico-arytenoid muscle. Towards the 

 outer limit of this surface there will be seen on each side a little 

 cavity which is smooth for articulation with the thyroid cartilage. 



Fig. 29. 

 Cartilages of the Larynx, Viewed from the Left Side. 



1. Epiglottis; 2. Body of the thyroid cartilage ; 3. Wing of the same cartilage ; 4. Superior cornu 

 of the same ; 5. Inferior cornu of the same ; 6. Foramen for the superior laryngeal nerve ; 7. Corni- 

 culum laryngis ; 8. Posterior surface of the left arytenoid cartilage ; 9. Ring of the cricoid cartilage ; 

 10. Bezel of the same cartilage. 



The inferior border is notched in the middle line of the bezel, and is 

 connected by ligament to the first ring of the trachea. The upper 

 border has a wide notch in front ; and posteriorly, over the bezel, it 

 shows a pair of smooth, convex facets for articulation with the arytenoid 

 cartilages. In texture the cricoid is composed of hyaline cartilage. 



The Thyroid Cartilage receives its name from covering the front and 

 sides of the larynx like a shield. It consists of a median thickened 

 portion, or body ; and two lateral plates — the alae, or wings. The body 

 is known in human anatomy as " Adam's apple " — the pomum Adami. 



