Shown is the cross section of a gerbil inner ear. The mammalian inner ear has three fluid filled spaces, scala tympani, scala media, and scala vestibuli. The fluid filled spaces coil from the base to the apex of the cochlea. Scala tympani and scala vestibuli are filled with perilymph, a sodium rich extracellular solution. Scala media contains the organ of Corti and the tectorial membrane, which help converting sound induced tissue vibrations into electrical signals that can be read by the brain. The fluid in scala media is the potassium rich endolymph. For normal cochlear function it is important that the high potassium concentration is maintained in the endolymph. Stria vasularis, which forms one of scala media's boundaries, maintains the high potassium concentration in the endolymph. . |
