Circular fold

Definition

Circular folds, also known as plicae circulares, are deep, permanent folds in the lining of the small intestine. These folds significantly increase the surface area for absorption and slow down the movement of food.

Related terms

Villi:

Finger-like projections that cover the surface of the small intestine, increasing its absorptive capacity.

Microvilli:

Small hair-like structures on the epithelial cells of villi that further amplify absorptive surface area in the small intestine.

Absorption:

The process by which nutrients from digested food are taken into the bloodstream through the walls of the intestines