CARTILAGES OF THE LARYNX 



1211 



meeting in the angle produce the laryngeal prominence [prominentia laryngea] 

 ("Adam's apple"), which is seen on the front of the neck. The horizontal in- 

 ferior margin presents near its middle the inferior thyreoid tubercle [tuberculmn 

 thyreoideum inferius], and in the median line the inferior thyreoid notch [incisura 

 thyreoidea inferior]. The thick posterior margin of each lamina is continued above 

 the superior edge in the long superior cornu [cornu superius], and below the inferior 

 margin in the short inferior cornu [cornu inferius]. The former is directed slightly 

 backward and medial ward, and joins with the end of the greater cornu of the 

 hyoid b}' ligament. The inferior cornu, curving medialward as it descends, articu- 

 lates by a flat, circular facet upon the medial side of its extremity with the ^thy- 

 reoid articular surface of the cricoid cartilage. The external surface of the lamina 

 affords {attachment for muscles and presents in its upper posterior part the 



Fig. 



973. — Cartilages op the Larynx seen from behind in Their Natural Positions. 

 The Cuneiform Cartilage is Somewhat Higher than Normal. (Merkel.) 



Epiglottic cartilage 



Corniculate cartilage 



Arytaenoid cartilage 



,- — Superior cornu of thyreoid 



Cuneiform cartilage 



Thyreoid cartilage 



Inferior cornu of thyreoid 



Cricoid 



Median crest 



superior thyreoid tubercle [tuberculum thyreoideum superius] ; in its lower part 

 the inferior thyreoid tubercle. The internal surface of the thyreoid cartilage is 

 smooth. 



A thyreoid foramen [foramen thyreoideum], sometimes seen in the upper part of the lamina, 

 giving passage to the superior laryngeal artery, results from the incomplete union of the fourth 

 and fifth branchial cartilages from which the laminiB are derived. The oblique line [linea 

 obliqua], extending between the thyreoid tubercles, is commonly present and is regarded by 

 many anatomists as a normal feature of the external surface of the thjTeoid cartilage. It 

 marks the attachment of the sternohyoid and thyreohyoid muscles. At the insertion of the 

 vocal ligaments in the angle of the laminae a small perichondral process is often observed. 



The arytaenoid cartilages [cartilagines arytsenoideae] (figs. 973, 977, 978, 

 979), paired, surmount the lamina of the cricoid cartilage and give attachment to 

 the vocal ligaments, whose relations and state of tension are altered by the changes 

 in position which these cartilages are almost constantly undergoing. 



Each cartilage is pyramidal in form, and moulded for the attachment of several 

 muscles. The apex, which is above, is bent backward and medialward and is 

 connected with a corniculate cartilage. The base, somewhat triangular in shape, 

 presents at the lateral and posterior part an oval or circular concave articular 

 surface [facies articularis], directed medialward and downward to meet the 

 arytaenoid articular surface of the cricoid cartilage. The lateral angle of the base 

 is prolonged into a stout muscular process [processus muscularis] for the attach- 



