do veins carry blood to the heart or away
Vein Veins are blood vessels that carry blood toward the heart. Most veins carry deoxygenated blood from the tissues back to the heart; exceptions are the pulmonary and umbilical veins, both of which carry oxygenated blood to the heart. In contrast to veins, arteries carry blood away from the heart.
Renal vein The renal veins are veins that drain the kidney. They connect the kidney to the inferior vena cava. They carry the blood filtered by the kidney.