Ductus venosus

Ductus venosus is a small vein in the fetus that diverts some blood flow away from the liver and sends it directly to the heart. It forms a part of the fetal circulation system and is essential for proper development and growth of the fetus.

Anatomy

The ductus venosus is located within the umbilical cord and is connected to the umbilical vein, which carries oxygenated blood from the placenta to the fetus. The other end of the ductus venosus is connected to the inferior vena cava, which carries deoxygenated blood back to the heart.

Function

The primary function of the ductus venosus is to bypass the liver, which is not fully functional in the fetus. This allows the oxygenated blood from the placenta to be delivered directly to the heart, where it can be distributed to the rest of the body. The ductus venosus also plays a role in regulating the volume of blood that flows to the liver.

Closure

After birth, the ductus venosus closes and becomes a ligament known as the ligamentum venosum. This process is triggered by the increase in blood oxygen levels that occurs when the baby begins to breathe on its own. If the ductus venosus fails to close properly, it can lead to a condition known as patent ductus venosus.

Clinical significance

A patent ductus venosus can cause a variety of health problems, including heart failure, liver disease, and pulmonary hypertension. Treatment typically involves surgical closure of the ductus venosus.

See also

• Fetal circulation
• Umbilical vein
• Inferior vena cava
• Ligamentum venosum
• Patent ductus venosus

• 
  Diagram of the fetal circulation, showing the ductus venosus
• 
  Diagram of the liver, showing the ductus venosus
• 
  Agenesis of ductus venosus in a human