When teaching about fetal circulation, which vessel carries oxygenated blood from the placenta to the fetus?

The umbilical vein is responsible for carrying oxygenated blood from the placenta to the fetus. In fetal circulation, the placenta serves as the organ of oxygen and nutrient exchange. The oxygen-rich blood from the placenta travels through the umbilical vein towards the fetus, providing the necessary oxygen and nutrients for growth and development.

This unique pathway is crucial because the fetus does not rely on its lungs for oxygenation; thus, the umbilical vein is vital for delivering oxygenated blood directly to the fetal circulation. Understanding this process is essential, as it highlights the differences between fetal and postnatal circulation, where the lungs take over the responsibility of oxygenation after birth.

In contrast, the other vessels mentioned have different and specific functions within fetal circulation. The umbilical artery carries deoxygenated blood away from the fetus back to the placenta, while the ductus venosus is a shunt that helps direct blood from the umbilical vein into the inferior vena cava, bypassing the liver. The aorta serves as a major vessel carrying blood from the heart to the body, but it is not directly responsible for transporting oxygenated blood from the placenta to the fetus.