CHAPTER XIII 



THE AUDITORY APPARATUS 



THE human organ of hearing consists of the external ear, 

 bounded within by the drum membrane (tympanic membrane, 

 membrana tympani); the middle ear, a cavity filled with air 

 which communicates with the pharynx through the auditory 



Tympanic cavity, with chain of ossicles 

 Semicircular duct 

 Utricle j 

 Ductus endolymphaticus 



Saccule 

 Ductus cochlearis 



Auricula 



Auditory tub 



Membrana tympani 



Recessus epitympanicus 



External acoustic meatus 



Fig. 90. Diagrammatic view of the parts of the human ear. 

 Cunningham's Anatomy.) 



(From 



or Eustachean tube and contains the auditory ossicles; and the 

 internal ear, a complex bony chamber, the bony labyrinth, 

 within which is the membranous labyrinth containing the specific 

 receptors or sensory surfaces of the internal ear (Fig. 90). The 



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