The urinary system consists of the kidneys, ureters, urinary bladder, and urethra, which filter blood and subsequently produce, transport, store, and intermittently excrete urine (liquid waste).

By eliminating fluid and waste, the urinary system regulates important physiological parameters, such are blood volume and consequently the blood pressure, the pH of the blood by eliminating acids and bases, and electrolyte balance by sophisticated mechanisms of reabsorbtion and excretion which depend upon the needs of the body.

Source: https://www.kenhub.com/en/library/anatomy/urinary-system