The body uses a number of different ways to get rid of waste products and unwanted substances that are produced in the body or that we get from food or drink. In the lungs, for instance, the blood drops off carbon dioxide, which we then exhale. The blood get rid of waste products in the intestines, which leave the body with the faeces. The liver and kidneys act as the body's own sewage plants, which take care of and break down harmful substances. From the kidneys, the filtered substances are led away with the urine through the ureters and down to the bladder, where they leave the body through the urethra. In this film you will learn more about the different functions that clean our body.