How is the structure of a villi in the small intestine related to its function?
The intestinal villi are small finger like projections that extend into the lumen of the small intestine. Each villus has many microvilli projecting from its epithelial surface, collectively forming a brush border.
Villi are specialised for absorbtion and have very thin walls which are 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.
Lymph capillaries in the villi collect absorbed triglycerides, cholesterol and fat soluble vitamins and transport it back to the blood very slowly.