500
Explain how a kidney functions.
The renal artery brings blood into the kidney. This blood supplies oxygen and nutrients to the cells of the kidneys and picks up the cells' waste products. Then, the blood is filtered. The water and chemicals are dumped into tubes called nephrons. As the chemicals and water travel through the nephrons, cells absorb specific amounts of water and chemicals which get put back into the blood. Any water and chemicals left over get sent to the renal pelvis and out of the kidney. The cleaned blood leaves through the renal vein.