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AUDITORY BIOPHYSICS 



of the basilar membrane, the cells of Hensen, the organ of Corti, and the 

 tectorial membrane. 



Tectorial Membrane 



The tectorial membrane extends the whole length of the scala media. 

 It is described by Hardesty [1908] as consisting of a hyaline matrix, 

 probably keratin, in gelatinous form, in which are embedded numerous 

 fine fibers or threads of uniform size.. It is slightly elastic and semi- 



External 



spiral 

 ligament 



Fig. VII-17. A section through the cochlea showing how the tectorial membrane 

 rests with its lower surface on the hair cells protruding above the surface of the organ 

 of Corti. The basilar membrane is under tension. Its fibers extend from the inter- 

 nal bony shelf to the external spiral ligament. Note how the lower surface of the 

 basilar membrane is reinforced to resist distortion. This composite group of tissues 

 is referred to as the aural membrane. 



solid, and possesses marked adhesiveness. Its density is only slightly 

 greater than that of the endolymph in which it is submerged. In the 

 pig it is about five times as wide and five times as thick in the apical turn 

 as at the basal end. Its apical section has an area about twenty-one 

 times and a volume ninety-five times the area and volume at its basal 

 end. Its free liplike margin (Fig. VII-17) rests lightly upon the hair 

 cells of the organ of Corti. 



