Vena azygos

Vena Azygos

The Vena Azygos is a significant vein within the human body that is responsible for draining the thoracic wall and the abdominal wall. It is part of the azygos system, which is a network of veins located in the thoracic cavity.

Anatomy

The vena azygos originates in the abdominal cavity and ascends through the diaphragm at the level of the T12 vertebra. It then ascends in the posterior mediastinum to the right of the thoracic aorta and the thoracic duct. The vena azygos drains into the superior vena cava just before it enters the right atrium of the heart.

Function

The primary function of the vena azygos is to drain blood from the thoracic and abdominal walls. It serves as a major collateral pathway for blood to return to the heart, especially when the inferior vena cava or superior vena cava are blocked.

Clinical Significance

The vena azygos can be affected by various medical conditions. For instance, azygos continuation is a rare congenital anomaly where the inferior vena cava is absent, and the vena azygos takes over its function. In addition, enlargement of the vena azygos, known as azygos vein dilatation, can be a sign of superior vena cava obstruction.

See Also

• Hemiazygos vein
• Accessory hemiazygos vein
• Azygos system
• Superior vena cava
• Inferior vena cava