Cochlea cells. Scanning electron micrograph (SEM) of a section through part of the cochlea inside a human ear. The rows of columnar outer pillar cells run along the organ of Corti, the auditory sense organ. The outer pillar cells arise from the basilar membrane, and their upper surfaces form part of the surface of the organ of Corti. This organ lies on the basilar membrane, an internal surface of the cochlear duct. The organ of Corti also contains hair cells (not seen) and an over- lying tectorial membrane (removed). Sound waves deform hair cell cilia & trigger auditory nerve impulses. Magnification: x5000 at 6x7cm size.