<prompt> Urachus is the remnant ofAllantoisMeckels diveiculumUmbilcal aeryLeft umbilical vein  <response>: xThe developing bladder is continuous cranially with the allantois.it is unceain whether the allantois contributes to the formation of the bladder .the allantois atrophies and is seen in postnatal life as a fibrous band the urachus extending from the apex of bladder to umbilicus Ref Human embryology Inderbier Singh Tenth edition Page no 292 