Which organ's primary function is to eliminate excess water and waste products from the body?

The kidneys are vital organs responsible for filtering blood to remove waste products and excess water, which they excrete as urine. This process is crucial for maintaining the body’s fluid and electrolyte balance, as well as regulating blood pressure. The kidneys also play an important role in homeostasis by controlling the composition of body fluids; they adjust the amount of water and salts reabsorbed back into the bloodstream depending on the body’s needs.

In comparison, the liver primarily functions in metabolizing nutrients, producing bile for digestion, and detoxifying various metabolites. The bladder is responsible for storing urine produced by the kidneys, while the pancreas has roles in digestion and regulating blood sugar levels through insulin production. Each of these organs contributes significantly to bodily functions but does not play the primary role in waste and excess water removal like the kidneys do.