The urinary system consists of two kidneys, two ureters, a urinary bladder, and a urethra. The kidneys filter waste from the blood to produce urine. The ureters carry urine from the kidneys to the bladder. The bladder stores urine until urination, at which point urine passes through the urethra and out of the body. Together these structures work to regulate fluid balance and remove waste via urine production and storage.