Microscopic views of tissue samples taken from the small intestine by biopsy. At left are normal villi. At right, in the tissue from a celiac patient, the villi have flattened and disappeared.
Microscopic finger-like projections that line the inner wall of the small intestine. (Singular: villus.) After food passes from the stomach into the small intestine, nutrients in the food are absorbed into the body through the villi. Every person has millions of villi in his intestines.
In patients with untreated celiac disease, inflammation in the small intestine makes the villi shrink and flatten.
The illustration is reprinted with permission from the University of Iowa Health Care’s magazine for physicians Currents, 2003, 4:2(Spring): David Elliott, Management of celiac disease.