Retina. Coloured scanning electron micrograph (SEM) of rods (yellow) and cones (green) in the retina of the eye. The outer nuclear layer is purple. Magnification x1800 when printed at 10 centimetres wide. [F0010041] Incredible!!
Rods (green) are long nerve cells which respond to dim light, enabling images to be detected. Cones (blue) are shorter cone-like cells which detect colour. Rods and cones pass visual signals through the optic nerve to the brain. Pigment cells block light from passing further.
Inner ear hair cells. Coloured scanning electron micrograph (SEM) of sensory hair cells from the inner ear. These cells are surrounded by a fluid called endolymph. As sound enters the ear it causes waves to form in the endolymph, which in turn cause the hairs to move. The movement is converted to an electrical signal that is passed on to the brain. Each crescent-shaped arrangement of hairs lies atop a single cell.
Nerve cells. Coloured scanning electron micrograph (SEM) of nerve cells, known as neurones. Nerve cells occur in the brain, spinal cord, and in ganglia. Each nerve cell has a large cell body (brown) with several long processes extending from it. The processes usually consist of one thicker axon and several thinner branched dendrites. The dendrites collect information in the form of nerve impulses from other nerve cells and pass it to the cell body.