Question

How do the villi of the small intestine function?

Answer 1

Villi of small intestine increases surface area of absorption and the overlying cells absorb digested nutrients from intestinal lumen.

Explanation:

Villi increase the absorptive surface also by possessing microvilli: microscopic finger like projections on the cell surface. Villi (plural) are finger like projections present on inner wall of small intestine. These are covered by columnar epithelial cells like some other parts of GI tract. Inside each villus (singular) there are extensive blood capillaries and prominent lymphatic vessel.

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Except digested dietary fat and fat soluble vitamins, other nutrients are absorbed and delivered in blood capillaries. Fat is transferred as chylomicron (microscopic droplets) to lymphatic vessel within each villus where a milky fatty fluid accumulates, called chyle.