How most of our excretory system is not dedicated to excreting; it’s dedicated to reabsorbing.

Not all animals use the same routes or excrete their wastes the same way humans do. Excretion applies to metabolic waste products that cross a plasma membrane.

The excretory system works with the respiratory, endocrine, urinary and digestive system. It works with the respiratory system because it helps the lungs get rid of carbon dioxide and water vapors. It works with the digestive system to help get rid of wastes that you eat through the anus.