Background Info

The two primary arteries that supply blood to the kidneys stem from the descending aorta and enter each kidney at its central, concave region known as the hilum. Once inside the kidneys, the arteries branch multiple times while moving blood through the renal medulla to the renal cortex.

Near the renal medulla and cortex border, the arteries divide into smaller arterioles and capillaries that provide blood to the kidney’s nephrons. These coiled, elongated tubules span the renal medulla and cortex and serve as the kidney’s functional units. They and their associated vessels filter waste products from the blood while reabsorbing essential substances.

Finally, the purified blood exits the kidneys through veins that flow into the inferior vena cava. This large vein then transports the blood back to the heart.