Ductus venosus
In the fetus, the ductus venosus (Arantius' duct after Julius Caesar Aranzi) shunts a portion of umbilical vein blood flow directly to the inferior vena cava. Thus, it allows oxygenated blood from the placenta to bypass the liver. Compared to the 50% shunting of umbilical blood through the ductus venosus found in animal experiments, the degree of shunting in the human fetus under physiological conditions is considerably less, 30% at 20 weeks, which decreases to 18% at 32 weeks, suggesting a higher priority of the fetal liver than previously realized. In conjunction with the other fetal shunts, the foramen ovale and ductus arteriosus, it plays a critical role in preferentially shunting oxygenated blood to the fetal brain. It is a part of fetal circulation.
| Ductus venosus | |
|---|---|
Fetal circulation. The ductus venosus (red) connects the umbilical vein to the inferior vena cava. | |
The liver and the veins in connection with it, of a human embryo, twenty-four or twenty-five days old, as seen from the ventral surface. | |
| Details | |
| Source | Umbilical vein |
| Drains to | Inferior vena cava |
| Artery | Ductus arteriosus |
| Identifiers | |
| Latin | ductus venosus |
| Anatomical terminology | |