593. The VOCAL CORDS, or ligaments, are formed of elastic and parallel fibres, enclosed in a fold of mucous membrane. They are about two lines in width, and pass from the anterior angle of the thyroid cartilage, to the two arytenoid cartilages. 271 The one is called the superior, and the other the inferior vocal ligament. The cavity, or depression between the superior and inferior ligament, is called the ventricle of the larynx. The aperture, or opening between these ligaments, is called the glot´tis, or chink of the glottis. It is about three fourths of an inch in length, and one fourth of an inch in width, the opening being widest at the posterior part. This opening is enlarged and contracted by the agency of the muscles appropriated to the larynx.
Fig. 104.
Fig. 105.
Fig. 104. An ideal, lateral section of the larynx. 1, 1, The upper vocal cords. 2, 2, The lower vocal cords. 3, 3, The glottis. 4, 4, The ventricles of the larynx.
Fig. 105. A vertical section of the larynx. 2, The os hyoides. 4, The apex of the epiglottis. 7, The superior vocal ligament. 9, The ventricle of the larynx. 10. The lower vocal ligament. 11, The arytenoid cartilage. 12, 13, The cricoid cartilage. 14, The trachea. 18, The œsophagus.
591. Describe the arytenoid cartilages. 592. What is said of the epiglottis? 593. Give the structure of the vocal cords. Where is the ventricle of the larynx? Where is the glottis situated? What is represented by fig. 104? Explain fig. 105.