Images Dated 4th October 2001

Stereocilia in ear, SEM

Stereocilia in ear. Coloured scanning electron micrograph (SEM) of stereocilia (yellow) in a healthy inner ear. The inner ear converts sound waves into nerve impulses by stimulation of the stereocilia, which project from the ends of sensory hair cells. Sound waves entering the inner ear displace the fluid that surrounds the stereocilia, causing the stereocilia to bend. This bending causes the release of neurotransmitter chemicals, which generate nerve impulses that travel to the brain along the auditory nerve. The inner ear can transmit information about the loudness and pitch of a sound. Magnification: x2185 at 6x7cm size

© SUSUMU NISHINAGA/SCIENCE PHOTO LIBRARY

Pea flower stigma, SEM

Pea flower stigma. Coloured scanning electron micrograph (SEM) of the surface of a common or garden pea flower (Pisum sativum) stigma. This is part of the female reproductive structure (pistil), which is formed from one or more carpels. Each carpel possesses a stigma, with a style and an ovary (not seen). The stigma is covered in projections known as papillae (green). These trap pollen grains (yellow) that contain the male sex cells. If the male cells fertilise the female sex cells (ovules) in the ovary, the carpel may ripen to produce a fruit containing seeds. Magnification: x140 at 6x7cm size

© SUSUMU NISHINAGA/SCIENCE PHOTO LIBRARY