What are microvilli primarily used for in epithelial cells?

Microvilli are tiny, finger-like projections found on the surface of epithelial cells, particularly those in the intestines and kidneys. Their primary function is to increase the surface area of the cell. This expanded surface area is crucial for enhancing absorption capabilities. In the intestines, for example, the increased surface area provided by microvilli allows for a greater number of transport proteins and enzymes to be present, which facilitates the efficient absorption of nutrients from digested food. This is especially important for maximizing the uptake of essential vitamins, minerals, and other nutrients, thus playing a vital role in overall digestion and nutrient assimilation.

While protection against pathogens, signaling between cells, and storage of nutrients are important functions of various cellular components and systems, they are not the primary role of microvilli. Microvilli are specifically adapted structures that optimize the functional capacity of epithelial cells involved in absorption.