How does the excretory system of an animal help to maintain homeostasis?

Question

I have to do a project on the excretory system in animals, and it asks How the excretory system helps maintain homeostasis. If any one knows enough about this and could tell me I would really appreciate it

Answer 1

- Urea is removed in the kidneys to maintain it at non toxic levels.

- C02 is removed in the lungs to prevent CO2 poisoning.