omphalomesenteric duct
vitelline duct

Meckel's diverticulum: Portion of the omphalomesenteric duct of the small intestine, it is present in only 2% of the population.

It is a vestigial remnant of the omphalomesenteric duct (also called the vitelline duct), and is the most frequent malformation of the gastrointestinal tract.

In the human embryo, the vitelline duct, also known as the omphalomesenteric duct, is a long narrow tube that joins the yolk sac to the midgut lumen of the developing fetus.

The omphalomesenteric duct (omphaloenteric duct, vitelline duct or yolk stalk) normally connects the embryonic midgut to the yolk sac ventrally, providing nutrients to the midgut during embryonic development.

A Meckel's diverticulum, a true congenital diverticulum, is a slight bulge in the small intestine present at birth and a vestigial remnant of the omphalomesenteric duct (also called the vitelline duct or yolk stalk).

Omphalomesenteric duct cysts (ODC, also known as an omphalomesenteric duct remnant or vitelline cyst) are developmental defects relating to the closure of the omphalomesenteric duct.