RESPIRA TION 



28! 



temperature before being introduced, so as to prevent the 

 condensation of moisture on it. 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 extent from front to back 

 is really concerned in the respiratory act. In deep expiration 

 the vocal cords come nearer to the middle line, and the glottis 



FIG. 121. DIAGRAM OF LARYNGOSCOPE. 



is narrowed ; in deep inspiration they are widely separated, and 

 the rings of the trachea, and even its bifurcation, may be dis- 

 closed to view. When a sound is produced a note sung, for 

 example the cords are approximated (Figs. 122 and 123) ; 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 bead. Chest 

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

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

 this can be distinctly felt by the hand. In head notes or falsetto 

 the resonance is chiefly in the upper cavities, the pharynx, mouth. 



