What does villi in the small intestine do?
Intestinal villi are small finger like projections, that extend into the lumen of the small intestine.
Each villus has many micro villi projecting from its epithelium, collectively forming a brush border.
The villi and micro villi, increase intestinal absorptive surface area providing exceptionally efficient absorbtion of nutrients in the lumen. Certain digestive enzymes are also present on their surfaces which aid in digestion.
They are specialised for absorption and have very thin walls ( single cell thick ) . This enables shorter diffusion path. They have a rich blood supply to keep a concentration gradient.
Villus capilaries collect amino acids and simple sugars and absorb them into the blood stream.
Lymph capillaries in the villi collect absorbed triglycerides, cholesterol and amphipathic proteins and transport it to the rest of the body through the lymph fluid.