The derivatives of the midgut include distal part of the duodenum (ie, the part distal to opening of the common bile duct), jejunum, ileum, cecum and vermiform appendix, ascending colon, and right two thirds of the transverse colon. All these derivatives are supplied by the superior mesenteric artery.
In the 4th week of development the midgut is suspended from the posterior abdominal wall by a short dorsal mesentery and opens into the yolk sac through a wide communication. This communication gradually narrows down to a slender tube known as the yolk stalk (also called vitello-intestinal duct or vitelline duct). The yolk sac itself now lies within the developing umbilical cord.