RESPIRA TION 



265 



temperature before being introduced, so as to prevent the 

 condensation of moisture on it. And the tendency to retch 

 which is caused by contact of the instrument with the soft 

 palate may be removed or lessened by the application of a 

 solution of cocaine. 



Examined with the laryngoscope during quiet respiration, 

 the glottis is seen to be moderately, though not widely, 

 open, and the vocal cords almost motionless. Although the 

 portion between the arytenoid cartilages has received the 

 name of glottis respiratoria, in contradistinction to the 

 glottis vocalis between the vocal cords, the rima in its whole 



FIG. 94. POSITION OF THE 

 GLOTTIS PRELIMINARY TO 

 THE UTTERANCE OF SOUND. 



rs, false vocal cord ; ri, true 

 vocal cord ; ar, arytenoid carti- 

 lage ; 6, pad of the epiglottis. 



FIG. 95. POSITION OF OPEN 

 GLOTTIS. 



/, tongue ; e, epiglottis ; ae, ary- 

 epiglottidean fold ; c, cartilage of 

 Wrisberg ; ar, arytenoid cartilage ; o, 

 glottis ; v, ventricle of Morgagni ; ti, 

 true vocal cord ; ts t false vocal cord. 



extent from front to back is really concerned in the re- 

 spiratory act. In deep expiration the vocal cords come 

 nearer to the middle line, and the glottis is narrowed ; in 

 deep inspiration they are widely separated, and the rings of 

 the trachea, and even its bifurcation, may be disclosed to 

 view. When a sound is produced, a note sung, for example, 

 the cords are approximated (Figs. 94 and 95) ; and with a 

 high note more than with a low. 



The essential difference between the production of notes in the 

 lower register, or chest voice, and in the higher register, or falsetto, 

 has been much debated. The lowest notes which can be uttered by 

 any given voice are chest notes, the highest are falsetto notes ; but 

 there is a debatable land common to both registers, and medium 

 notes can be sung either from the chest or from the head. Chest 

 notes impart a vibration or frtmitus to the thoracic walls, from the 

 resonance of the lower air chambers, the trachea and bronchi ; and 



