Which organ filters waste from the blood and regulates water balance?

Which organ filters waste from the blood and regulates water balance?

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

Answer: (C)

The main idea tested is which organ handles filtering waste from the blood and keeping the body's water balance steady. The kidneys do this by filtering blood through tiny units called nephrons. They remove waste products like urea, excess salts, and toxins, forming urine. At the same time, they adjust how much water is reabsorbed back into the body, influenced by hormones such as ADH and aldosterone. This regulatory process ensures the right volume and concentration of body fluids, helping maintain electrolyte balance and blood pressure. Other organs have different roles. The lungs primarily expel carbon dioxide and water vapor, not by filtering blood waste or controlling water balance. The liver detoxifies chemicals and processes nutrients, while the heart pumps blood throughout the body. None of these regulate waste filtration and water balance as directly as the kidneys do. So, the organ that filters waste from the blood and regulates water balance is the kidney.

The main idea tested is which organ handles filtering waste from the blood and keeping the body's water balance steady. The kidneys do this by filtering blood through tiny units called nephrons. They remove waste products like urea, excess salts, and toxins, forming urine. At the same time, they adjust how much water is reabsorbed back into the body, influenced by hormones such as ADH and aldosterone. This regulatory process ensures the right volume and concentration of body fluids, helping maintain electrolyte balance and blood pressure.

Other organs have different roles. The lungs primarily expel carbon dioxide and water vapor, not by filtering blood waste or controlling water balance. The liver detoxifies chemicals and processes nutrients, while the heart pumps blood throughout the body. None of these regulate waste filtration and water balance as directly as the kidneys do.

So, the organ that filters waste from the blood and regulates water balance is the kidney.