What are projections inside the small intestine that increase the surface area for absorption of nutrients?

What are projections inside the small intestine that increase the surface area for absorption of nutrients?

• A. Villi
• B. Microvilli
• C. Plicae circulares
• D. Haustra

Answer: (A)

Villi are the finger-like projections of the mucosa that line the small intestine, and they are the key feature that dramatically increases the surface area available for nutrient absorption. Each villus contains a lamina propria with a capillary network and a central lacteal, enabling quick uptake of monosaccharides, amino acids, and fats into the bloodstream and lymphatic system. The surface of these villi is covered by enterocytes with microvilli, which form the brush border and provide even more absorptive surface. Other features like plicae circulares are circular folds that boost surface area, but they are folds rather than projections into the lumen, and haustra are characteristic of the large intestine. So the projections responsible for the major rise in absorptive surface in the small intestine are the villi.

Villi are the finger-like projections of the mucosa that line the small intestine, and they are the key feature that dramatically increases the surface area available for nutrient absorption. Each villus contains a lamina propria with a capillary network and a central lacteal, enabling quick uptake of monosaccharides, amino acids, and fats into the bloodstream and lymphatic system. The surface of these villi is covered by enterocytes with microvilli, which form the brush border and provide even more absorptive surface. Other features like plicae circulares are circular folds that boost surface area, but they are folds rather than projections into the lumen, and haustra are characteristic of the large intestine. So the projections responsible for the major rise in absorptive surface in the small intestine are the villi.