Inside each kidney, about one million tiny units called nephrons rid the body of excess and unwanted substances.
Each nephron has two parts, the glomerulus and the tubules.
Inside the glomerulus large amounts of fluid, dissolved substances such as minerals, and waste products are filtered from the blood and form a substance called filtrate. From the glomerulus, this filtrate flows into the tubules.
Inside the tubules, most of the water is re-absorbed in the blood, in addition to the required amounts of minerals and other substances your body needs. At the same time, excess substances or “filtrate” flow into the tubules and are eliminated as urine.
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