Vitelline duct connects the yolk sac to the small intestine. This duct obliterates when the embryo is about 6 weeks old. Complete failure of the duct to obliterate results in a fistula from the ileum to the umbilicus (vitelline fistula).
In theĀ human embryo, theĀ vitelline duct, also known as theĀ vitellointestinal duct,Ā theĀ yolk stalk,Ā theĀ omphaloenteric duct,Ā or theĀ omphalomesenteric duct,Ā is a long narrow tube that joins theĀ yolk sacĀ to theĀ midgutĀ lumenĀ of the developingĀ fetus.Ā It appears at the end of the fourth w
Enterohepatic circulation
Enterohepatic circulationĀ refers to the circulation ofĀ biliary acids,Ā bilirubin, drugs or other substances from theĀ liverĀ to theĀ bile, followed by entry into theĀ small intestine, absorption by theĀ enterocyteĀ and transport back to the liver. Enterohepatic circulation is an especially importa