Intestinal microvilli. Coloured transmission electron micrograph (TEM) of a section through microvilli from the small intestine. These tiny structures (dark red) form a dense brush-like covering on the absorptive surfaces of the cells lining the small intestine. These cells absorb nutrients from digested food through these microvilli. There are billions of microvilli in a small intestine. Magnification: x20'000 when printed at 10 centimetres wide.