microvillus One of a number of minute finger-like projections on the free surfaces of epithelial cells. Microvilli are covered with plasma membrane and their cytoplasm is continuous with the main cell cytoplasm. Their purpose is probably to increase the absorptive or secretory surface area of the cell, and they are abundant on the villi of the intestine, where they form a brush border.

microvillus A small, finger-like projection. Microvilli are found in large numbers on the free surfaces of many cells. They serve to increase the surface area-to-volume ratio of a cell and are a particular feature of those with an absorptive function, e.g. the epithelial cells of the intestine, and renal tubules.