What is the main function of columnar epithelium?

The main function of columnar epithelium is indeed absorption. This specialized epithelial tissue is characterized by its tall, column-like cells, which often contain microvilli on their surface. Microvilli are tiny projections that increase the surface area available for absorption, making columnar epithelium particularly effective in regions of the body where the uptake of nutrients and other substances is crucial, such as in the intestines.

While secretion, protection, and diffusion are also important functions associated with different types of epithelial tissues, columnar epithelium is predominantly recognized for its role in facilitating the absorption of substances. For instance, in the lining of the intestines, the columnar epithelial cells help absorb nutrients from digested food into the bloodstream, highlighting its primary function.