Which feature helps villi in the small intestine absorb digested food efficiently?

The structure of the villi is specifically designed to maximize absorption in the small intestine, and having a single layer of surface cells is a key feature of this design. The thinness of this layer allows for a greater surface area and shorter distance for nutrients to diffuse into the blood capillaries found beneath. This enhances the efficiency of nutrient absorption, as digested food molecules, such as amino acids and glucose, can pass rapidly from the intestine into the bloodstream.

The presence of microvilli on the surface of these cells further increases the surface area, promoting even more effective absorption. Typically, a thick wall or multiple layers of cells would hinder the speed at which substances can pass through, while a lack of blood supply would prevent nutrients from being transported away from the intestine. Hence, the efficiency of nutrient absorption in the small intestine is maximized by the single layer of cells that constitutes the villi.