In the fetus,<unk>  shunts a significant minority of the blood flow of the umbilical vein directly to the inferior vena cava. Thus, it allows oxygenated blood from the placenta to bypass the liver. In conjunction with the other fetal shunts, the foramen ovale and<unk>  arteriosus, it plays a critical role in preferentially shunting oxygenated blood to the fetal brain.<unk>  is open at the time of the birth and is the reason why umbilical vein catheterization works.<unk>  naturally closes during the first week of life in most full-term neonates; however, it may take much longer to close in pre-term neonates. Functional closure occurs within minutes of birth. Structural closure in term babies occurs within 3 to 7 days.
After it closes, the remnant is known as ligamentum venosum.
Ductus venosus
Sinus venosus
Coronary sinus
Aortic sinus
Coronary sulcus
Brachiocephalic vein
Descending aorta
Cardiac veins