Yolk stalk

Yolk stalk: A narrow tube present in the early embryo that connects the midgut of the embryo (through the umbilical opening) to the yolk sac outside the embryo. Later in development, the yolk stalk is usually obliterated but a remnants of it may persist, most commonly as a finger-like protrusion from the small intestine known as Meckel’s diverticulum. Found in 2-4% of people, Meckel’s diverticulum may become inflamed much like the appendix and require surgical removal. The yolk stalk is also called the umbilical duct, vitelline duct, or oomphalomesenteric duct.