The urinary system includes the kidneys, ureters, bladder, and urethra. Its purpose is to maintain the volume and chemical composition of fluids in the body.

The urinary system – also known as the renal system – produces, stores and eliminates urine, the fluid waste excreted by the kidneys. Urinary system functions and urinary system diseases are ...

It swells into a round shape when it is full and gets smaller when empty. If the urinary system is healthy, the bladder can hold up to 450 – 500 ml of urine comfortably for 2 to 5 hours.