The role of excretory system is to remove all the waste from our body, both fluid and solid. For example urine, it is a product of our kidneys that help our bodies balance salts and fluids in our bodies.
Excretory system has connection with both endocrine and circulatory system. In this case we are going to focus on the circulatory.
The blood that's rushing through our body passes through our left or right kidney. That way, uric acid, urea and water are eliminated from the blood and the leftovers of the water get back into our system.