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

The major functions of this system are:

• To produce, store and void excretory product - the urine.
• The kidney eliminates waste products. These are mainly the nitrogenous end products of protein catabolism by the liver. The kidneys regulate ion balance, water content, help to stabilise blood pressure, and they also secrete a glycoprotein hormone called erythropoietin, which stimulates production of red blood cells in myeloid tissue.
• Urine leaves the kidney and is transported via the ureters to the urinary bladder, a muscular-walled temporary storage chamber. Urine is voided through the urethra, which opens to the exterior.