Major veins of the thoracic and abdominal walls:
Common iliac veins
- Merge to form the inferior vena cava, which ascends through the thorax.
- Drains into the common iliac vein; it receives the 5th lumbar vein.
- Drain into the common iliac veins; they ascend along the lumbar vertebrae.
- Drains into the ascending lumbar vein.
- Subcostal and ascending lumbar veins form the azygos vein, which drains directly into the superior vena cava, which also drains the brachiocephalic veins.
- Receives venous drainage from the 11th to 4th right posterior intercostal veins.
- Drains into the arch of the azygos vein; the right superior intercostal vein is the final tributary of the azygos vein before it drains into the superior vena cava.
- Merging of ascenidng lumbar and subcostal veins on left side of the body
- Hemiazygos vein ascends through the thorax, it drains the left posterior intercostal veins 11-8.
- Drains into the azygos vein.
This venous junction connects drainage of the lower and upper torso regions.
Accessory hemiazygos vein
- Descends along the superior posterior thoracic wall on the left side of the body and typically drains into the azygos vein.
- Drains the 7th-4th posterior intercostal veins on the left side of the body.
- Drains into the brachiocephalic vein; it receives the musculophrenic vein and anterior intercostal veins.