Main Entry: azygos vein Function: noun : any of a system of three veins which drain the thoracic wall and much of the abdominal wall and which form a collateralcirculation when either the inferior or superior vena cava is obstructed; especially: a vein that receives blood from the right half of the thoracic and abdominal walls, ascends alongthe right side of the vertebral column, and empties into the superior vena cava —compare ACCESSORY HEMIAZYGOSVEIN, HEMIAZYGOS VEIN
azygos veinn. A vein that arises from the right ascending lumbar vein or the inferior vena cava, ascends through the aortic orifice of the diaphragm, lies in the posterior mediastinum, and terminates in the superior vena cava.
