Kidneys are bean-shaped, very complex organ of human body. They occur in pair, each about a size of respective individual’s fist. Each individual needs at least one kidney to stay alive.
They play a very important role in the day to day functioning of our body. They balance the amount of fluid required in our body & it purifies our blood by removing the metabolic wastes from our blood stream.This filtering process is carried out by more than a million tiny filters called as Nephrons. Each Nepron is said to be the stuctural & functional unit of kidney.
Here is a video which explains about the functioning of our kidneys in detail.