What happens in the small intestines? The small intestine (small bowel) is about 20 feet long and about an inch in diameter. Its job is to absorb most of the nutrients from what we eat and drink. Velvety tissue lines the small intestine, which is divided into the duodenum, jejunum, and ileum.
The primary function of the villi in the small intestine is to increase the absorption of nutrients from food passing through the small intestine. Intestinal villi are small thread-like objects that line the intestines in order to effectively increase the surface area of the intestinal wall.