codon 73Scanning electron micrograph (SEM) of a vertical section through part of the cochlea inside a human ear. The section shows part of the
row of columnar outer pillar cells that runs along the organ of Corti, the auditory sense organ. The outer pillar cells arise from the basilar
membrane (across bottom), and their upper surfaces (across top) form part of the surface of the organ of Corti. This organ lies on the basi-
lar membrane, an internal surface of the cochlear duct. The organ of Corti also contains hairlike cilia (not seen) and an overlying tectori-
al membrane (removed). Sound waves deform hairlike cilia and trigger auditory nerve impulses. Magnification: ×600 at 6 ×7 cm size.
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