THE LARYNX. 



1821 



sexes a little above the middle of a line from the bottom of the thyroid notch to the 

 lower border of the thyroid. Taguchi ' gives the average distance in men from the 

 notch to the vocal cord as 8.5 mm., and from below as 10.5 mm. In women he 

 finds these distances 6.5 mm. and 8 mm. respectively. The cords arise either di- 

 rectly from the thyroid, just on each side of the depth of the angle, or from a 



Fig. 1549. 



False vocal cord 

 Vocal cord 

 Ventricle of larynx 



Arytenoid cartilage 

 Thyroid cartilage , 



Sterno-hyoid 



Ventricle of larynx 

 Bursa 



Thyro-hyoid 

 Pharynx 



Omo-hyoid 



Sterno-mastoid 



Internal 

 jugular vein 



Sterno-mastoid 



Internal 

 jugular vein 



Pneumogastric nerve , 

 Carotid artery 



Palato-pharyngeus 



Prevertebral fascia 



Thyro-arytenoideus 

 Inferior pharyngeal constrictor 

 Arytenoideus 



Anterior part of section across neck at level of false vocal cords ; on left side ventricle of larynx is exposed. 



median cartilaginous nodule, or from one for each cord, the distance between them 

 being 1.5 mm. in both sexes. The false cords arise about 3.5 mm. above the true 

 ones, and, on the average, 4 mm. apart from each other. The true cords are tri- 

 angular on section, with a sharp free edge, an upper surface slanting downward and 

 outward from it, a longer internal surface which slants steeply downward and out- 

 ward, and an imaginary attached base placed laterally. The free edge is composed 

 of the whitish ligament which shows through the thin and closely attached mucous 

 membrane. The substance is chiefly muscular tissue from the thyro-arytenoid, which 

 forms a three-sided prism, giving a solidity which the false cord lacks. Behind 

 the cords the glottic-region is bounded by the arytenoid cartilages, and, as the true 



Fig. 1550. 



/? 



Base of tongue 



Epiglottis — 



Vocal cord 



Aryteno-epigrlottic fold 



Sinus pyriformis 



Vocal process 



Cuneiform tubercle' 



Tubercle of Santorini 



-Lateral glosso- 

 epiglottic fold 



-Median glosso- 

 epiglotfic fold 



-Epiglottis 



False vocal cotd 

 Ventricle of larynx 

 Vocal cord 



Rima glottidis 

 Cuneiform tubercle 

 Vocal process 



Tubercle 

 of Santorini 



Interior of larynx as seen with lar>ngoscope. A, rima glottidis widely open ; B, rima glottidis closed. 



cords end at the vocal processes, a considerable part of the chink of the glottis is 

 bounded by these cartilages. The posterior part between them is called the respira- 

 tory, and the anterior, between the cords, the vocal ^2.xt. According to Moura,^ the 

 entire length of the chink in the male is 23 mm., of which the vocal part is 15.5 mm. 



^ Archiv f. Anat. u. Phys., Anat. Abth., 1889. 

 ''■ Bull, de I'Acad. de Medecine, Paris, 1879. 



