550 



MUSCLE-NERVE PHYSIOLOGY 



lower teeth by means of a handkerchief. The warm mirror is passed to the 

 back of the mouth, until it rests upon and slightly raises the base of the uvula, 

 and at the same time the light is directed upon it: an inverted image of the 



FIG. 346. The Parts of the Laryngoscope. 



larynx and trachea will be seen in the mirror. If the dorsum of the tongue 

 be alone seen, the handle of the mirror must be slightly lowered until the 

 larynx comes into view; care should be taken, however, not to move the mirror 



FIG. 347. To Show the Position of the Operator and Patient when Using the 



Laryngoscope. 



upon the uvula, as it excites retching. The observation should not be pro- 

 longed, but should rather be repeated at short intervals. 



The structures seen will vary somewhat according to the condition of the 

 parts as to inspiration, expiration, phonation, etc. They are the following: 



