Theintestinal epitheliumis folded into finger-like projections called thevilli(villus, singular). The main purpose of the villi is to increase the surface area of the small intestine which is essential for efficient nutrient uptake.

The villi can be several millimeters in length and consist of thousands of cells. The villi are supported by thelamina propria, a loose web of connective tissue, which predominately consists of extracellular macromolecules, such as proteoglycan, polysaccharides, and collagen. This network of fibers is intercepted by blood and lymph vessels, which carry away the absorbed nutrients.

The villi should not be confused with the microscopic cell extensions calledmicrovilli.

Figure 1:Light microscopy image of villi.