Caption: Macrophage engulfing TB bacteria. Coloured scanning electron micrograph (SEM) of a macrophage white blood cell (red) engulfing a tuberculosis (Mycobacterium tuberculosis) bacterium (yellow). This process is called phagocytosis. Macrophages are cells of the body's immune system. They phagocytose and destroy pathogens, dead cells and cellular debris. Magnification: x750 when printed at 10 centimetres tall.
False-color SEM of retina featuring central fovea, a crater-like depression in the photosensitive layer of the eye. The foveal retina is the area of greatest visual acuity and contains only cone receptor cells.
Retina. SEM of a section through a human retina, the light-sensitive tissue that lines the inside of the eye. Light entering the eye passes through several layers of cells before reaching the light receptors. From top to bottom are seen: cell bodies of optical ganglion cells (pale red), which form the optic nerve; cell bodies of bipolar neurons and cell bodies of the receptor cells (red); and the rod (white) and cone (yellow) receptors. Rod cells different
The bacteria appear pink. The macrophage (appearing blue) is stretching out and engulfing (eating) them. Macrophages are a type of white blood cell which acts as a 'Pacman' in our bodies - it eats foreign bodies (like bacteria) and digests them. This is part of your body's front line defense against invaders.
Bone tissue. Coloured scanning electron micrograph (SEM) of a section through an osteoclast bone cell in reabsorbing bone matrix, showing the cell's nucleus (round, centre). Osteoclasts remodel bone by degrading and reabsorbing it in response to growth or changing mechanical stress. A border of complex branching microprojections (thread-like) can be seen anchoring the cell to the bone matrix. Magnification: x2500 when printed 10 centimetres wide.