Fetus in utero (English)

While in the uterus, the fetus is surrounded by a thin double layered membrane called the amniotic sac. The inner layer (closer to the fetus) is also known as the amnion, while the outer layer (closer to the uterus) is also known as the chorion. The amniotic sac is filled with amniotic fluid that surrounds and bathes the fetus during development.The fetus is connected to the placenta via the umbilical cord. The umbilical cord has two umbilical arteries that carry the deoxygenated blood from the fetus. In contrast, a single umbilical vein carries oxygenated blood, rich in nutrients from the mother to the fetus.