Vessel
Superior vena cava
The final upper-body venous channel to the right atrium
High-yield
The SVC returns systemic venous blood from the upper body; pulmonary venous return normally reaches the left atrium by separate vessels.
Overview
The SVC forms from the two brachiocephalic veins and descends along the right mediastinum. It receives the azygos arch before entering the superior right atrium. Its lower segment is enclosed by the pericardial sac.
Reference facts
- Origin
- Union of right and left brachiocephalic veins
- Course
- Down the right mediastinum, with an intrapericardial lower segment
- Branches
- The azygos vein is its principal additional tributary
- Drains to
- Right atrium, returning blood from the head, neck, upper limbs and much of the thoracic wall
Clinical correlation
Obstruction can cause upper-body venous congestion. The severity and collateral pattern depend on the location, speed of obstruction and available alternative channels, not just the size of the blockage.
Frequently asked questions
Where does the superior vena cava originate?
The superior vena cava arises from the union of right and left brachiocephalic veins.
Where does the superior vena cava drain to?
The superior vena cava drains to the right atrium, returning blood from the head, neck, upper limbs and much of the thoracic wall.
What are the tributaries of the superior vena cava?
The azygos vein is its principal additional tributary.
What is the course of the superior vena cava?
Down the right mediastinum, with an intrapericardial lower segment.