Kidney — The primary function of the kidneys is to filter blood, removing waste products and excess substances to produce urine.
Ureter — The ureters are thin tubes that transport urine from the kidneys to the urinary bladder.
Urinary bladder — The urinary bladder stores urine until it is ready to be expelled from the body.
Urethra — When the bladder if full, the urine is expelled out through the urethra.
Skin — The skin excretes waste products like excess water, salts, traces of urea and uric acid in the form of sweat, through sweat glands located underneath the skin.