PHONATION; ARTICULATE SPEECH. 



573 



its widest part, during quiet respiration is about 13.5 mm. in men 

 and 11.5 mm. in women (Semon). With the advent of phonation 

 the vocal membranes are at once 

 approximated, and to such an 

 extent that the glottic opening is 

 reduced to a mere slit. It is then 

 spoken of as the rima glottidis, or 

 chink of the glottis. 



The space above the vocal bands, 

 the supra-glottic or supra-rimal 

 space, is triangular in shape and 

 extends from the pharyngeal open- 

 ing to the plane of the vocal bands. 

 The mucous membrane lining the 

 walls of this space, presents on either 

 side, just above the vocal bands, a 

 crescentic fold which runs from 

 before backward, and is known as 

 the false vocal band or cord. Be- 

 tween the true and false bands 

 there is a cavity or space prolonged 

 upward and outward for some 

 distance, forming what is known as 

 the ventricle of the larynx. The 

 space below the vocal bands, the 

 infra-glottic or infra-rimal space, is 

 narrow above and elongated from 

 before backward, but wide and 

 circular below, corresponding to the 

 lumen of the trachea. 



The Laryngeal Cartilages, 

 Articulations, and Ligaments. 

 The cartilages which compose the 

 framework of the larynx are nine 

 in number, three of which are 

 single: viz., the cricoid, the thyroid, 

 and the epiglottis, while six occur 

 in pairs: viz., the arytenoids, the 

 cornicula laryngis, and the cunei- 

 form. 



The cricoid cartilage is the 

 foundation cartilage, and affords 

 support to the remaining cartilages 



and the structures attached to them. In shape it resembles a signet- 

 ring, the broad quadrate portion of which is directed backward, 



19 



FIG. 260. LONGITUDINAL^ SECTION 

 or THE HUMAN LARYNX, SHOW- 

 ING THE VOCAL BANDS. i. 

 Ventricle of the larynx. 2. Supe- 

 rior vocal cord. 3. Inferior vocal 

 cord. 4. Arytenoid cartilage. 5. 

 Section of the arytenoid muscle. 

 6, 6. Inferior portion of the cavity 

 of the larynx. 7. Section of the 

 posterior portion of the cricoid 

 cartilage. 8. Section of the an- 

 terior portion of the cricoid car- 

 tilage. 9. Superior border of the 

 cricoid cartilage. 10. Section of 

 the thyroid cartilage. n, n. 

 Superior portion of the cavity of 

 the larynx. 12, 13. Arytenoid 

 gland. 14, 1 6. Epiglottis. 15,17. 

 Adipose tissue. 18. Section of 

 the hyoid bone. 19, 19, 20. 

 Trachea. (Sappey.) 



