How do villi aid digestive processes in the small intestine?
Intestinal villi are small finger like projections that extend into the lumen of the small intestine. Each villi has several micro villi on its epithelium, collectively forming a brush border.
The villi and micro villi increase the intestinal absorptive surface providing exceptionally efficient absorption of nutrients in the lumen.
Certain digestive enzymes are present on their surface, aiding in digestion.
Villi are specialised for absorption and have very thin walls ( single cell thick ) . This enables a shorter diffusion path . They have a rich blood supply to keep a concentration gradient.
Villus capillaries 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 lymph fluid.