Blood, sweat, tears, and a few other bodily liquids we don't talk about in polite company are the main body fluids you know. There are plenty more you might not know, but they all work together to make you exist and function properly. For example, have you ever heard of interstitial fluid?
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Interstitial Fluid, AKA tissue fluid, works in conjunction with lymph and plasma (the liquid part of your blood) to maintain your body’s internal pressure and make sure your organs and other fluids properly interact. Most interstitial fluids have a specific job and a specific name, like peritoneal fluid, which lubricates everything inside the abdomen, or pleural fluid, which coats the lungs to allow them to do that whole oxygen exchange thing so you can live. And you were giving air all the credit.
Read about the rest and what they do at mental_floss. Link