Q.Why are Villi present in the intestine and not in the stomach ?

Villi are finger-like projections that increase surface area for absorption, so they occur where the body actually absorbs nutrients — the intestine — and not in the stomach, where digestion (not absorption) is the primary role.

The stomach and the small intestine perform different primary jobs in the alimentary canal. The stomach's inner lining is thrown into folds called rugae and dotted with gastric pits leading to gastric glands, which secrete gastric juice (HCl, pepsin, mucus) to churn and chemically break down food (mainly proteins) into a semi-fluid chyme; the stomach absorbs only very limited substances (such as water, alcohol, and a few drugs) and is not specialised for large-scale nutrient absorption. The small intestine, by contrast, is where digestion is completed (with the help of bile, pancreatic juice, and intestinal juice) and where the vast bulk of nutrient absorption — of monosaccharides, amino acids, fatty acids, vitamins, and minerals — actually takes place. To support this heavy absorptive workload, the intestinal mucosa is folded into millions of tiny, finger-like projections called villi (further covered with even smaller microvilli, forming a 'brush border'), which dramatically increase the internal surface area available for nutrient uptake into the underlying blood cap …