608 EXAMINATION OF THE LARYNX. 



.ventricularis) covering the false vocal band or the ventricular ligament 

 (L. v. s.). On the lower, lip-shaped border of the entrance to the larynx 

 may be distinguished the posterior lower notch of the ostium pharyn- 

 geum laryngis (above P.); and on either side of this the apices of the car- 

 tilages of Santorini (5. S.) are visible, resting on the apices of the aryten- 

 oid cartilages; immediately behind is the adjacent pharyngeal wall (P.). 

 In the ary-epiglottic ligaments (W . W.) are the cuneiform cartilages of 

 Wrisberg, and finally, external to these, may be recognized the depres- 

 sions of the sinus piriformes (5. p.). 



Special attention should be given to the condition of the glottis and 

 the vocal bands during respiration and phonation. During quiet respira- 

 tion the chink of the glottis (Fig. 213) appears as a lancet-shaped slit, 

 which is wider during life than in the cadaver. If deep respirations are 

 taken, the chink widens considerably (Fig. 215), and if the mirror is 

 favorably placed, it may be possible to see the rings of the trachea, and 

 even the bifurcation. When the voice is produced, the glottis closes 

 each time to a narrow slit (Fig. 214). 



Appendix. Rhinoscopy. The nasal cavity has important relations to speech 

 and to respiration. By the introduction of a mirror bent at an angle, with the 



reflecting surface directed upward, it is pos- 

 sible gradually to survey a field such as is 

 reproduced in Fig. 217. 



In the middle appears the nasal septum 

 (5. .) , on either side the longitudinally oval 

 choanae (CTt.), and further below the soft 

 palate (P. m.} with the pendant uvula (/.) 

 On the borders of the choanal openings may 

 be recognized the posterior portions of the 

 inferior (C. i.), middle (C. m.) and superior 

 (C. s.} turbinated bones, with the corre- 

 sponding nasal meatus beneath each one. 

 Least distinct are the upper turbinated bone 

 and the lower meatus. At the uppermost 

 part a strip of the roof of the pharynx 

 (O. R.) may yet be seen, with the more or 

 less developed pharyngeal tonsil. This 

 s !f te , r <rtntu is composed of. lymphatic 



a repeated shifting of the mirror is necessary glandular tissue, and extends in an arch- 

 in order to obtain the entire image as is given like manner over the roof of the pharynx 



between the openings of the two Eustachian 

 tubes (T. T.~). External to the mouth of 

 the Eustachian tube on each side is the so-called tubal eminence (W.), and still 

 more external the fossa of Rosenmuller (R.). 



For the study of the larynx experimentation on the excised larynx is further 

 of importance, as carried out by Ferrein in 1741 and especially by Johannes 

 Muller in 1839. The latter conducted the air into an excised human larynx 

 through a tracheal tube the air-tension of which was measured by a communicating 

 mercurial manometer. The bases of the arytenoid cartilages were held in a fixed 

 position against each other by means of a suture; while a cord passing over a 

 pulley and carrying weights drew the thyroid cartilage forward. By increasing 

 the tension the tones could be raised about z\ octaves. When the tension re- 

 mained the same, stronger blasts of air raised the tone to the fifth. The tone 

 was not lowered by placing tubes over the larynx to increase its length, but these 

 measures modified the timbre and increased the resonance of the note. 



Landois employed the fresh, living, excised larynx from the dog or the sheep; 

 the muscles being stimulated by various pairs of electrodes, while a bellows supplied 

 the air through a tracheal tube. In this way the most reliable information con- 

 cerning the action of the various muscles can be obtained. 



The Rontgen rays have recently been applied with success to the study of 

 the position of the laryngeal cartilages and the hyoid bone, and also of the soft 

 palate. 



