Data in this chapter may be updated by a PubMed search using the keywords: structure, anatomy, cell biology; inner ear, endolymph, perilymph; cochlea, vestibular hair cell, supporting cell, organ of Corti, inner hair cell, outer hair cell, spiral ganglion, stria vascularis, spiral ligament, basilar membrane, tectorial membrane, Reissner’s membrane , utricle/utricular, saccule/saccular, crista, macula/maculae, type1 hair cell, type 2 hair cell and dark cells.