Used with permission from the Wellcome Trust, http://images.wellcome.ac.uk. License: UK CC-NC-ND 2.0. No cropping is allowed.
A scanning electron microscope image of the sensory hair bundle of an inner hair cell from a guinea pigs hearing organ in the inner ear. Vibrations made by sound cause the hairs to be moved back and forth, alternately stimulating and inhibiting the cell. When the cell is stimulated it causes nerve impulses to form in the auditory nerve, sending messages to the brain.