Which organ's main function includes filtering blood, removing waste, and regulating fluid balance?

Which organ's main function includes filtering blood, removing waste, and regulating fluid balance?

• A. Liver
• B. Kidneys
• C. Lungs
• D. Heart

Answer: (B)

The kidneys are responsible for filtering blood, removing waste, and regulating fluid balance. Blood is filtered through tiny units called nephrons, where plasma is turned into filtrate. As this filtrate travels through the renal tubules, essential water and electrolytes are reabsorbed while wastes and excess ions are secreted into the urine. This system keeps body fluids, electrolyte levels, and acid-base balance in check, and it also helps regulate blood pressure through hormonal control. Other organs have important roles too—like the liver for metabolism and detoxification, the lungs for gas exchange, and the heart for pumping blood—but they aren’t primarily performing the filtering and fluid-balance tasks the kidneys handle.

The kidneys are responsible for filtering blood, removing waste, and regulating fluid balance. Blood is filtered through tiny units called nephrons, where plasma is turned into filtrate. As this filtrate travels through the renal tubules, essential water and electrolytes are reabsorbed while wastes and excess ions are secreted into the urine. This system keeps body fluids, electrolyte levels, and acid-base balance in check, and it also helps regulate blood pressure through hormonal control. Other organs have important roles too—like the liver for metabolism and detoxification, the lungs for gas exchange, and the heart for pumping blood—but they aren’t primarily performing the filtering and fluid-balance tasks the kidneys handle.