My biology instructor says that the kidneys are like processors. Everything we consume--the food, the medicines and other compounds get processed by the kidneys. Our kidneys decide what needs to be thrown out of the body and what needs to stay and how much. This way it keeps our body in equilibrium so that it can function well.
I think this is really impressive. It's sort of like a computer or a machine. How does it know how to do all this stuff?