The female and male urinary system are very similar, differing only in the length of the urethra. Urine is formed in the kidneys through a filtration of blood. The urine is then passed through the ureters to the bladder, where it is stored. During urination, the urine is passed from the bladder through the urethra to the outside of the body. 800–2,000 milliliters (mL) of urine are normally produced every day in a healthy human.