Coloured scanning electron micrograph (SEM) of a section through the organ of Corti in the cochlear of the inner ear. Outer hair cells (red) are across top, with their nerve fibres (pink) below them. Around the nerve fibres are Deiters', or phalangeal, cells (brown), a type of support cell. On top of the hair cells are hairs (stereocilia, not seen) that are surrounded by endolymph fluid. As sound enters the ear, it causes waves to form in the endolymph, which in turn causes these hairs to move. Outer hair cells amplify the vibrations, which are then picked up by inner hair cells (not seen) that transmit the signal to auditory nerve fibres. This amplification enhances the sensitivity and dynamic range of hearing. Magnification: x6,600 when printed at 15cm wide.