Urachus is the remnant of
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
Allantois
Meckel's diveiculum
Umbilcal aery
Left umbilical vein
General anatomy