Intestinal villus. Cutaway illustration of an intestinal villus. Villi are the finger-like projections that increase small intestine surface area. The villus is covered by columnar epithelium (pink). The epithelial cells are mostly enterocytes (with black nuclei) involved in digestion. Amongst the enterocytes are the goblet cells (blue) producing mucus which lubricates food and prevents self digestion. To the inside of the columnar epithelium is the lamina propria. This contains the arterial (red) & venous (blue) blood supply and lymph vessels (green). It is into the blood that the products of digestion are absorbed. Nerves (yellow) are also present.