PHONATION; ARTICULATE SPEECH 



659 



runs from before backward, and is known as the false vocal band or cord. 

 Between the true and false bands there is a cavity or space prolonged up- 

 ward 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, cor- 

 responding to the lumen of the trachea. 



(Fig. 273.) 



The Laryngeal Cartilages, Articula- 

 tions, 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 cuneiform. (Figs. 

 274 and 275.) 



The cricoid cartilage is the foundation 

 cartilage, and affords support to the remain- 

 ing cartilages and the structures attached to 

 them. In shape it resembles a signet-ring, 

 the broad quadrate portion of which is directed 

 backward, while the narrow circular portion 

 is directed forward. It rests upon the upper 

 ring of the trachea, to which it is firmly at- 

 tached by fibrous tissue. The posterior upper 

 border of the quadrate portion presents on 

 either side an oval convex facet for articula- 

 tion with the arytenoid cartilage. The long 

 axis of this facet is directed downward, out- 

 ward, and forward. 



The thyroid, the largest of the laryngeal 



cartilages, is composed of two flat quadrilat- J^la^M/"?'. Section of the pos- 

 eral plates, united anteriorly at an angle of te rior portion of the cricoid carti- 

 about P 9 o degrees. Each plate is directed ^^^*S 

 backward and outward and terminates m a ^ superior border of the cricoid 

 free border, which is prolonged upward and cartilage, jo. Section of *** 

 downward for some distance, terminating in ^.^^ Se'carit'y of'the lax; 

 two processes, the superior and inferior cornua. ^ I3- Arytenoid gland. 14, 

 The upper border to the thyroid is deeply 

 notched in front. The inferior border over- 



19 



FIG. 273. LONGITUDINAL SEC- 

 TION OF THE HUMAN LARYNX, 

 SHOWING THE VOCAL BANDS, i. 

 larynx. 2. Supe- 

 3. Inferior vocal 

 cord. 4. Arytenoid cartilage. 5. 



j?> 2Q T rachea.-(Sa#>o>.) 



