The urinary system consists of two kidneys, two ureters, the urinary bladder, and the urethra.

The paired kidneys remove waste products from the blood, help regulate the composition of plasma, and perform certain hormonal functions. The system of tubules in each kidney coalesces into a single mucomus- cular tube, the ureter, which extends caudad to empty into the urinary bladder, a distensible reservoir for the storage of urine. When full, the urinary bladder discharges the urine through the urethra to the outside of the body.