The small intestine is not the only organ lined with villi. There is another type called chorionic villi that lines the lumen of the placenta. Chorionic villi surround a developing fetus during ...

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 ...