- Formed by two large tributaries- the right and left brachiocephalic veins
- Each brachiocephalic vein is formed in turn by two large tributaries, the subclavian vein bringing blood from the upper limb
- The internal jugular drains the head and neck.
- In addition to these veins the superior vena cava receives azygous vein draining the thoracic and upper abdominal walls.
- Thus the superior vena cava is the great channel draining blood from the head and neck both upper limbs, thoracic wall and the upper part of the abdominal wall.
- Formed at the lower border of the 1st costal cartilage
- Ends opposite the 3rd costal cartilage by entering the right atrium
- Upper half lies in the superior mediastinum and lower half which is intrapericardial in the middle mediastinum
- It is devoid of valves
Relations
Left
- Overlapped anteriorly by the ascending aorta
- Beginning of aortic arch
Right
- Right pleura
- Right phrenic nerve
Posterior
- Trachea
- Right vagus
- Root of right lung
Tributaries
- Two brachiocephalic trunk
- Azygous vein
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