Activated Macrophage : 2013

Photograph by

Steve Gschmeissner

About this image

Coloured scanning electron micrograph of a human macrophage. Macrophages derive from monocytes, a specialised type of white blood cell. Their role is to destroy pathogens and cellular debris by engulfing and digesting them. Activated macrophages have receptors that are specifically attracted to lymphokines, signal devices used by the immune system to target microbes or tumour cells. Human macrophages are typically about 20 micrometres in diameter. This image was created in monochrome and later digitally colourised. Bedford, Bedfordshire, United Kingdom