What is the primary function of villi in the small intestine?

The primary function of villi in the small intestine is to facilitate absorption. Villi are small, finger-like projections that line the walls of the small intestine, significantly increasing the surface area available for absorption. This enhanced surface area allows for more efficient uptake of nutrients, vitamins, and minerals from the digested food into the bloodstream. Each villus contains tiny blood vessels, called capillaries, which transport the absorbed nutrients to various parts of the body.

In addition to their role in absorption, the structure of villi helps to slow down the passage of food, allowing more time for digestion and nutrient absorption. This adaptation is crucial because the small intestine is the primary site for nutrient absorption, and the presence of villi maximizes the intestine's effectiveness in this function.