Final answer:
The veins of the spinal cord drain into the superior vena cava, with some of the lumbar veins draining into the azygos vein or hemiazygos vein.
Step-by-step explanation:
The veins of the spinal cord drain into the superior vena cava. The ascending lumbar veins drain into the azygos vein on the right or the hemiazygos vein on the left, while the remaining lumbar veins drain directly into the inferior vena cava.