Other Excretory ProcessesWhile we have explored the major excretory processes carried out by the respiratory and urinary systems, other organs and systems are also involved with excretion. For example, the liver produces pigments called biliverdin and bilirubin as it breaks down the heme portion of hemoglobin during the process of red blood cell destruction. These pigments are stored in the gall bladder and released with the bile, and are thus referred to as bile pigments. They ultimately leave the body in the feces.
Another example would be the sweat produced by sweat glands embedded in the skin. While sweat is mostly water and functions in cooling the body, it also contains small amounts of electrolytes, urea, and uric acid. Sweating is thus an excretory function.