EXAMINATION OF THE LARYNX. 



607 



v. Ziemssen showed that long, thin electrodes could be introduced as far as 

 the larynx under the guidance of the laryngoscope, and that the vocal bands 

 could be stimulated to activity by irritation of the muscles. Rossbach succeeded 

 in stimulating the muscles and nerves of the larynx externally through the skin. 



FIG. 214. Image of the Larynx when a Sound is 

 Begun. 



FIG. 215. View of the Trachea as far as the Bifurca- 

 tion. 



In this way physiological information may be gained, or therapeutic applications 

 may be made to the parts. 



Autolaryngoscopy was first employed by Garcia, and then by Czermak espe- 

 cially for the study of the movements of the larynx. If one introduce an illumi- 

 nated laryngoscopic mirror into his own throat, while placing the mouth opposite 

 a plane mirror, he may easily see 

 the picture of his own larynx re- 

 fleeted in the latter. 



The laryngoscopic picture 

 (Fig. 213) exhibits the follow- 

 ing details : L, the root of the 

 tongue, from the middle of 

 which the glosso-epiglottic 

 ligament passes downward ; 

 on each side of the latter are 

 the so-called valleculae (V V). 

 The epiglottis (E) appears as 

 an arch, shaped like the upper 

 lip; beneath it in quiet res- 

 piration is seen the lancet- 

 shaped chink of the glottis 

 (R), and on either side the 

 bright, yellowish vocal liga- 

 ment (L. v.). This vocal band 

 is from 6 to 8 mm. long in chil- 

 dren, from 10 to 15 mm. long 

 in women when relaxed, and 

 from 1 5 to 20 mm. when tense. 

 In men it measures from 15 

 to 20 mm. and from 20 to 25 

 mm. respectively. The whole 

 chink of the glottis is 23 mm. 

 long in men and 17 mm. in women; when the vocal bands are tense 

 27.5 and 20 mm. respectively. 



The width of the vocal bands varies from 2 to 5 millimeters. Ex- 

 ternal to the vocal band is the entrance (rima vestibuli) to the sinus of 

 Morgagni (S. M.), represented by a dark band. Still further outward, 

 and on a higher plane, may be seen the fold of mucous membrane (plica 



FIG. 216. Position of the Laryngeal Mirror in the Practice of 

 Rhinoscopy. 



