Villi

Definition

Villi are small, finger-like projections lining the interior of the small intestine that increase surface area for nutrient absorption. Each villus contains blood vessels and a lymphatic vessel to transport absorbed nutrients.

5 Must Know Facts For Your Next Test

1. Villi are covered with even smaller structures called microvilli, forming the brush border.
2. The increased surface area provided by villi is crucial for efficient nutrient absorption.
3. Villi contain capillaries and lacteals to facilitate both nutrient and fat absorption.
4. Damage to villi can lead to malabsorption syndromes, which can cause nutritional deficiencies.
5. Villi play a role in protecting against pathogens by housing immune cells.

Review Questions

• What function do villi serve in the small intestine?
• How do villi contribute to nutrient absorption?
• What might be the consequences of damaged or flattened villi?

Related terms

Microvilli: Tiny hair-like structures on the surface of villi that further increase surface area for absorption.

Lacteal: A lymphatic vessel located in the center of each villus responsible for absorbing fats.

Brush Border: The dense array of microvilli on the surface of intestinal cells that enhance absorption efficiency.