Biology - Villi and microvilli in the small intestine
Villi and microvilli in the small intestine
The inner surface of the small intestine is not smooth. It has a large
number of finger-like projections called (singular villus). Each villus
has further projections on it called The lumen  is the region of the
intestine through which food passes.
The villi and microvilli increase the surface area of the small intestine
approximately 600-fold. The internal surface area of the small intestine is
approximately, which is the area of a tennis court!
Having a large surface area in the small intestine is advantageous since
it provides a greater surface through which substances released by chemical
digestion can be absorbed into the blood system  and lymphatic system.