Medically reviewed by Robert Burakoff, MD Intestinal villi (singular: villus)are tiny, finger-like projections that line the interior (lumen) of the small intestine. The primary function of villi is ...

The chorionic sac encompasses the fetus and the amnion and is covered with chorionic villi until the 8th week. After the 8th week, these villi are constricted due to a decreased blood supply until ...