LIGAMENTS OF THE LARYNX. 



487 



Fig. 214* 



1. The ligaments which connect the thyroid cartilage with the os hyoides 

 are three in number : 



The two Thyro-hyoidean ligaments pass between the superior cornua of 

 the thyroid and the extremities of the greater cornua of the os hyoides : a 

 sesamoid bone or cartilage is found in each. 



The Thyro-hyoidean membrane is a broad membranous layer, occupying 

 die entire space between the upper border of the thyroid cartilage and the 

 upper border of the os hyoides. It is pierced by the superior laryngeal 

 nerve and artery. 



2. The ligaments connecting the thyroid to the cricoid cartilage are also 

 three in number : 



Two Capsular ligaments, with their synovial membranes, which form 

 the articulation between the inferior cornua of the thyroid and the sides 

 of the cricoid ; and the crico-thyroidean membrane. 

 The crico-thyroidean membrane is a fan-shaped 

 layer of elastic tissue, thick in front (middle crico- 

 thyroidean ligament) and thinner at each side (late- 

 ral crico-thyroidean ligament). It is attached by 

 its apex to the lower border and receding angle 

 of the thyroid cartilage, and by its expanded mar- 

 gin to the upper border of the cricoid and base of 

 the arytenoid cartilage. Superiorly it is continuous 

 with the inferior margin of the chorda vocalis. 

 The front of the crico-thyroidean membrane is 

 crossed by a small artery, the inferior laryngeal, 

 and is the spot selected for the operation of laryn- 

 gotomy. Laterally io is covered in by the crico- 

 thyroidei and crico-arytenoidei laterales muscles. 



3. The ligaments of the arytenoid cartilages are 

 six in number : 



Two Capsular ligaments, with synovial mem- 

 branes, which articulate the arytenoid cartilages 

 with the cricoid ; and the superior and inferior 

 thyro-arytenoid ligaments. The superior thyro-arytenoid ligaments are 

 two thin bands of elastic tissue which are attached in front to the receding 

 angle of the thyroid cartilage, and behind to the anterior and inner border 

 of each arytenoid cartilage. The lower border of this ligament constitutes 

 the upper boundary of the ventricle of the larynx. The inferior thyro- 



* A vertical section of the larynx, showing its ligaments. 1. The body of the os hyo- 

 ides. 2. Its great cornu. 3. Its lesser cornu. 4. The ala of the thyroid cartilage. 5. 

 The superior cornu. 6. Its inferior cornu. 7. The pomum Adami. 8, 8. The thyro- 

 hyoidean membrane ; the opening in the membrane immediately above the most pos- 

 terior of the numerals is for the passage of the superior laryngeal nerve and artery. 9. 

 The thyro-hyoidean ligament; the numeral is placed immediately above the sesamoid 

 bone or cartilage which exists in this ligament, a. The epiglottis, b. The hyo-epiglottic 

 ligament, c. The thyro-epiglottic ligament, d. The arytenoid cartilage ; its inner surface. 

 . The outer angle of the base of the arytenoid cartilage. /. The corniculum laryngis. 

 g. The cuneiform cartilage, h. The superior thyro-arytenoid ligament, t. The inferior 

 thyro-arytenoid ligament, or chorda vocalis; the elliptical space between the two thyro- 

 arytenoid ligaments is that of the ventricle of the larynx, k. The cricoid cartilage. /. 

 The lateral portion of the crico-thyroidean membrane, m. The central portion of thr- 

 same membrane, n. The upper ring of the trachea, which is received within the ring 

 of the cricoid cartilage, o. Section of the isthmus of the thyroid gland, p, p. The levn 

 tor glandulae thyroideae. 



