General

The intestinal wall

The inside of the intestinal wall is lined with millions of hairlike projections known as intestinal villi. These greatly expand the surface area of the small intestine. This provides a larger contact surface for the nutrients and facilitates their absorption into the blood.

Nutrients – as well as any drugs that might be present in the intestine – can pass through the cell membrane of the villi and enter the tiny blood vessels (capillaries) attached to them.