Why does the ductus venosus bypass the liver?
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.
What does the ductus arteriosus bypass?
Since the blood is already oxygenated after leaving the placenta and entering the body, the ductus arteriosus allows for it to bypass the pulmonary circulation and enter directly into the systemic circulation.
What is the structure used to bypass the liver in fetal circulation?
Explanation: Because the fetal lungs and liver are not fully functional until birth, the fetal circulation uses structures in order to bypass these organs. The ductus venosus is used to reroute blood from the fetal liver and deposit it into the right atrium.
What does the ductus venosus drain into?
The ductus venosus branches from the left umbilical vein and acts as a shunt allowing freshly oxygenated blood to bypass the fetal liver and flow directly into inferior vena cava.
What does the umbilical artery do?
The umbilical arteries carry deoxygenated blood from fetal circulation to the placenta. The two umbilical arteries converge together about at 5 mm from the insertion of the cord, forming a type of vascular connection called the Hyrtl’s anastomosis.
What is the point of the ductus venosus?
The primary function of the ductus venosus is to carry oxygenated blood from the umbilical vein to the inferior vena cava and, ultimately, the left heart for systemic circulation while the portal sinus supplies oxygenated blood to the liver itself.
How does the ductus arteriosus work?
The ductus arteriosus moves blood from the pulmonary artery to the aorta. Oxygen and nutrients from the mother’s blood are sent across the placenta to the fetus. The enriched blood flows through the umbilical cord to the liver and splits into 3 branches. The blood then reaches the inferior vena cava.
What is ductus venosus PI?
The ductus venosus is the very important part of fetal venous circulation. It plays a central role in return of venous blood from the placenta. This unique shunt carries well-oxygenated blood from the umbilical vein through the inferior atrial inlet on its way across the foramen ovale.
Where do umbilical arteries come from?
The umbilical artery originates from the anterior division of the internal iliac artery. In the fetus, it travels within the umbilical cord to the placenta and hence is the communication to the maternal circulation. After the umbilical cord has been cut at birth, clots form within the vessel and it obliterates.
What is the role of the ductus venosus?
The ductus venosus is a shunt that allows oxygenated blood in the umbilical vein to bypass the liver and is essential for normal fetal circulation. Blood becomes oxygenated in the placenta and travels to the right atrium via umbilical veins through the ductus venosus, then to the inferior vena cava.
