Ruptured venule. Coloured scanning electron micrograph (SEM) showing stacks (rouleaux) of red blood cells exposed inside a torn venule. A venule is a very small blood vessel in the microcirculation that allows deoxygenated blood to return from the capillary beds to the larger blood vessels (veins). Red blood cells are the most abundant cell in the blood. They have no nucleus and are about 7 micrometers across. Magnification: x2300 when printed at 10 centimetres wide.
Brain tumour. Coloured scanning electron micrograph (SEM) of a glioma, a type of tumour that arises from glial cells of the central nervous system. The most common site for gliomas is the brain. They can be either low or high-grade, with the latter having the worse prognosis. Magnification: x8000 when printed at 10 centimetres wide. Credit: STEVE GSCHMEISSNER
Nerve bundle. Coloured scanning electron micrograph (SEM) of a freeze-fractured section through a bundle of myelinated nerve fibres. Myelin sheaths (yellow) can be seen surrounding the axons (blue). Perineurium (connective tissue, pink) surrounds the nerve bundle while endoneurium divides the individual fibres.
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!!
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.