What is the function of microvilli?

• A. Increase surface area.
• B. Help in cell division.
• C. Secrete mucus.
• D. Facilitate cell motility.

Answer: (A)

Microvilli are tiny, finger-like extensions on the apical surface of certain epithelial cells, especially in the small intestine and kidney tubules. Their main role is to expand the cell’s surface area, creating a brush border that provides more membrane for nutrient transporters and digestive enzymes. This greatly enhances the rate of absorption because substances have more area to cross into the cell. The core of each microvillus is made of actin filaments, anchored to a terminal web, which supports these projections without making the cell motile. Because of this structure, microvilli are not primarily involved in cell division, mucus secretion, or cell movement—processes driven by other cellular components and specialized structures.