And along the lymph vessels we have these regions known as lymph nodes. And we'll talk about them in just a moment. And these lymph nodes essentially filter our lymph from different types of pathogenic agents. And eventually that lymph is returned back into our blood system via specific types of veins, as we'll see in just a moment. And the reason we want to return our lymph back into our blood is because we want to ensure that the same volume of blood remains in our cardiovascular system. So once again, the question is what happens to the 10% fluid that remains in the tissue space?