How many kidneys do you have?

The human body has two kidneys, located in the back of the abdominal cavity. The kidney's primary function is to filter the blood, which removes wastes from the body. In an adult, each kidney is approximately 4 to 5 inches long and shaped like a bean.

About 200 quarts of blood filters through the kidneys each day, which creates about 2 quarts of waste and water that becomes urine and drains to the bladder. The kidneys are connected to the vascular system via the renal arteries and receive approximately 20 percent of the blood pumped by the heart every minute. The kidneys are important in regulating the body's fluids, blood pressure, calcium level and electrolyte balance.