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Small intestine villus. Coloured scanning electron micrograph (SEM) of a villus from the mucosal lining of the small intestine. The mucosa is covered in many of these projections, which provide a surface for the absorption of digested food. The surface of the villus is composed mainly of absorptive enterocyte cells (pink), each of which is covered with many microvilli (not seen), microscopic hair-like structures which greatly increase the surface area for absorption. Several goblet cells (white, in surface depressions) are also seen. Goblet cells secrete a lubricating mucus onto the lining of the intestine. Magnification: x200 at 6x7cm size. (KEYSTONE/SCIENCE PHOTO LIBRARY/STEVE GSCHMEISSNER)