Which portion of the small intestine has the greatest absorptive surface area due to villi and microvilli?

• A. Duodenum
• B. Ileum
• C. Jejunum
• D. Cecum

Answer: (C)

The thing being tested is how the intestinal lining increases its surface area for absorption. Villi and microvilli dramatically boost the area available for nutrients to cross the mucosa. The jejunum has the tallest and most densely packed villi and an extensive brush-border with microvilli, along with pronounced circular folds (plicae circulares). This combination yields the greatest absorptive surface, making it the main site for nutrient uptake.

Other sections play important roles too: the duodenum starts digestion and absorption but doesn’t match the jejunum’s surface expansion; the ileum handles specific absorptions like bile acids and vitamin B12 but has less overall surface area than the jejunum; and the cecum, part of the large intestine, has far fewer absorptive villi and is less involved in nutrient absorption.