176 



ADVANCED LESSONS IN PRACTICAL PHYSIOLOGY 



19. Observation of the Interior of the Larynx in Man. Place a 

 light near the side of the subject's head. Seat yourself in front of him, 



FIG. 102. DIAGRAMMATIC REPRE- 

 SENTATION OP THE DIFFERENT PARTS OF 

 THE EAR. 



1, Pinna; 2, external auditory meatus ; 

 3, ear drum; 4, middle ear containing 

 the ossicles; 5, eustachian tube; 6, vesti- 

 bule of the internal ear; 7, auditory 

 nerve; dividing into two branches, one 

 of which innervates the cochlea, and the 

 other the semicircular canals; 8, parotid 

 gland. 



Lamp 



FIG. 103. DIAGRAMMATIC VIEW OF THE 



INTERNAL EAR. 



1, Tympanic cavity; 2, eustachian 

 tube; 3, incus; 4, stapes; 5, vestibule of 

 the internal ear (perilymph); 6, utricle; 

 7, central canal of the cochlea; 8, scala 

 vestibuli; 9, saccule; 10, endolymphatic 

 duct between saccule and utricle; 11, 

 ampulla of semicircular canal; 12, canalis 

 reunions; 13, scala tympani; 14, helico- 

 trema; 15, fenestra ovalis. 



Concave Mirror 



Zaryvx. 



FIG. 104. DIAGRAM OF LARYNGOSCOPE. (From Stewart's A Manual of Physiology, Wil- 

 liam Wood & Co., Publishers.) 



and direct him to incline his head slightly backward, to open his mouth, 

 and to hold his tongue forward with the aid of a handkerchief. Illumin- 

 ate the pharynx of the subject by means of a reflector fastened to your 



