Final answer:
The ductus venosus is responsible for shunting oxygen-rich blood from the placenta directly to the fetal heart, bypassing the semifunctional liver and facilitating the transportation of necessary oxygen and nutrients to support fetal development.
Step-by-step explanation:
Oxygen-rich blood is shunted from the placenta directly to the heart via the ductus venosus. Within the mother's womb, the placenta plays a crucial role in fetal development. It not only supplies blood rich in oxygen and nutrients via the umbilical vein, but also removes wastes in oxygen-depleted blood via the umbilical arteries.
The fetal circulatory system includes three major shunts: the foramen ovale, the ductus arteriosus, and the ductus venosus. The ductus venosus is particularly important as it allows the freshly oxygenated blood, which is high in nutrients, to bypass the semifunctional liver directly to the fetal heart.
The placenta serves as the juncture where oxygenated blood is transferred from the mother to the fetus. This blood, carrying necessary oxygen and nutrients, moves through the umbilical vein toward the heart. The ductus venosus, then diverts this blood from the liver and sends it to the inferior vena cava, which leads to the right atrium of the heart, effectively mixing with the fetal venous blood. This process is crucial because the fetus's lungs are immature and cannot oxygenate blood on their own.