Question: Where does the umbilical vein enter the circulation of the fetus?
Answer: the portal vein
Disambiguated annotations:
qaPairs: question: Where does less than a third of the blood from the umbilical vein enter the circulation of the fetus?
answer: Ductus venosus
ductus venosus and is carried to the inferior vena cava
question: Where does more than two thirds of the blood from the umbilical vein enter the circulation of the fetus?
answer: enters the liver proper from the inferior border of the liver
portal vein