What is the superior vena cava and what does it do?

The Superior Vena Cava (SVC) is a major vein, about 7 cm long, that returns deoxygenated blood from the upper half of the body to the right atrium of the heart.

Where is the superior vena cava located in the body?

It descends vertically behind the right border of the sternum, passing through the superior mediastinum and middle mediastinum, and terminates in the right atrium at the level of the right 3rd costal cartilage.

How is the superior vena cava formed?

It forms at the lower border of the right 1st costal cartilage by the union of the right and left brachiocephalic veins, which themselves are formed from the internal jugular and subclavian veins.

What are the main tributaries of the superior vena cava?

Its main tributaries include the right and left brachiocephalic veins, the azygos vein, and mediastinal and pericardial veins.

What structures are adjacent to the superior vena cava?

Key relations include the trachea, right pulmonary artery and bronchus posteriorly; the ascending aorta and brachiocephalic artery to the left; and the right phrenic nerve, pericardiophrenic vessels, and right lung/pleura to the right.

Does the superior vena cava have valves?

No, the SVC is valveless. Venous return from the upper body relies primarily on gravity and pressure differences.

What happens if the superior vena cava is obstructed?

Obstruction can lead to Superior Vena Cava Syndrome, with symptoms depending on the site. Collateral pathways, such as through the azygos vein or thoracoepigastric veins, may develop to bypass the blockage.

Superior Vena Cava (SVC) – Formation, Course & Tributaries

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