Wednesday, June 13, 2012

Scala Tympani

The scala tympani is a spiraling fluid-filled tube lying below the scala media and scala vestibuli, from which it is separated by the basilar membrane and spiral lamina respectively, in the cochlea. When the tympanic membrane transmits the vibrations coming in from the outer world to the ossicles, the stapes transmits them in turn to the oval window, causing the liquid (perilymph) inside the scala tympani and scala vestibuli to move in waves. These vibratory waves of liquid inside the scala vestibuli and scala tympani are transmitted down through the Reissner's membrane to the organ of Corti in the scala media (or cochlear duct); the hair cells of the organ of Corti pick the vibrations up and transform them into nerve impulses, which travel to the temporal lobe of the brain through the auditory nerve.