Brain cells. Coloured scanning electron micrograph showing neurones (large and grey) together with glial cells (red-orange). The latter form the special connective tissue of the central nervous system which has supportive and nutritive functions. Neurones consist of large cell bodies, containing the nucleus surrounded by cytoplasm, from which branch numerous dendrites seen here as thin tubules. Dendrites function as the major sites of information input into neurones; they either link neurones together or terminate in specialised sensory receptors. Magnification: x1700 at 6x7cm size.