528 THE LARYNX. 







The ligaments connecting the thyroid to the cricoid are 

 also three in number, a middle and two lateral. 



The middle crico-thyroid is a strong, yellow, and mem- 

 branous ligament attached above to the lower edge of the 

 thyroid, and below into the upper edge of the cricoid car- 

 tilage. This ligament gives passage to some small blood- 

 vessels, and is interesting from being the place of selection 

 for the operation of laryngotomy. The lateral crico thyroid 

 ligaments consist of the capsular and synovial membranes, 

 forming articulations between the inferior cornua of the 

 thyroid cartilage and the sides of the cricoid. 



The arytenoid cartilages have two sets of ligaments the 

 one connecting them with the cricoid, called the crico- 

 arytenoid the other with the thyroid, termed the thyro- 

 arytenoid ligaments. The first set consists of two capsular 

 ligaments and synovial membranes, by which the base of 

 the arytenoid cartilages articulate with the superior mar- 

 gin of the cricoid. This articulation allows a great free- 

 dom of motion. 



The second set comprises four ligaments, two superior, 

 and two inferior. The former are sometimes called false 

 ligaments, as they consist of little else than folds of mucous 

 membrane, containing some delicate fasciculi of elastic 

 fibres, which extend from the inner angle of the thyroid 

 to the anterior face of the arytenoid. 



The inferior thyro-arytenoid ligaments are true fibrous 

 chords, and constitute the chordce vocales. They extend 

 from the inner angle of the thyroid, horizontally back- 

 ward to the base of the arytenoid cartilage. These liga- 

 ments are strong, and consist of elastic and parallel fibres 

 which are associated with the thyro-arytenoid muscles, and 

 pursue the same direction. The space between these infe- 

 rior ligaments is the glottis or rima-glottidis. 



There are two proper ligaments of the epiglottis, the 

 ihyro-epiglottideus and the liyo-epiglottideus. The former 

 extends as a strong chord from the epiglottis to the inner 

 margin of the thyroid notch; the latter is seen as a thin 

 elastic membrane situated below the base of the os-hyoides 



