azygous vein

anatomy

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June 18, 2026

Quick Summary

The azygous vein is a blood vessel that plays a role in the venous drainage of the posterior body wall. It is part of a system that connects the superior and inferior vena cava, acting as a crucial link for blood return to the heart.1

The azygous system includes the azygous vein, hemiazygous vein, and accessory hemiazygous vein. These veins collect blood from the intercostal spaces, esophagus, lymph nodes, pericardium, and lungs. The right azygous vein specifically refers to the azygous vein located on the right side of the vertebral column. This vein ultimately empties into the superior vena cava.12

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vena cava
Superior vena cava.
A large vein, the azygos, which receives oxygen-poor blood from the chest wall and the bronchi, opens into the superior vena cava close to the point at which the latter passes through the pericardium, the sac that encloses the heart. The superior vena cava extends down about 7 cm…
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A large vein, the azygos, which receives oxygen-poor blood from the chest wall and the bronchi, opens into the superior vena cava close to the point at which the latter passes through the pericardium, the sac that encloses the heart. The superior vena cava extends down about 7 cm…
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human cardiovascular system
Superior vena cava and its tributaries
…cava receives blood from the azygous vein and small veins from the mediastinum (the region between the two lungs) and the pericardium. Most of the blood from the back and from the walls of the chest and abdomen drains into veins lying alongside the vertebral bodies (the weight-bearing portions of…
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…cava receives blood from the azygous vein and small veins from the mediastinum (the region between the two lungs) and the pericardium. Most of the blood from the back and from the walls of the chest and abdomen drains into veins lying alongside the vertebral bodies (the weight-bearing portions of…
Read More