How do nephrons work to filter waste and regulate fluid balance in the kidneys?

Nephrons are the functional units of the kidneys responsible for filtering waste and regulating fluid balance. Blood enters the nephron through the glomerulus, where waste products are filtered out and collected in the tubules. The filtered fluid, called filtrate, is then processed through reabsorption and secretion to maintain the body's fluid balance. Finally, the remaining waste products and excess fluids are excreted as urine.