The organ system that includes the kidneys, ureters, bladder, and urethra. The kidneys form urine from blood plasma by filtration, reabsorption, and secretion. The formation of urine includes the excretion of waste products, but the kidneys also regulate the water and mineral content and the acid-base balance of the blood and all other body fluids. The other organs of the system are concerned with the elimination of urine after it has been formed.


Figure: URINARY SYSTEM