Which organ is primarily responsible for excreting water and other waste products?

The kidneys are primarily responsible for excreting water and other waste products from the body. They filter blood to remove excess fluids, electrolytes, and toxins, which are then excreted as urine. This process is crucial for maintaining the body's fluid balance and ensuring that harmful substances are eliminated effectively. The kidneys play a vital role in regulating blood pressure, electrolyte levels, and acid-base balance, further emphasizing their importance in waste excretion.

While the liver also processes waste products and plays a role in detoxification, its primary function is related to metabolism and the production of bile. The lungs are responsible for gas exchange, expelling carbon dioxide but not primarily for fluid waste, while the skin aids in waste regulation through perspiration but is not the main organ for waste excretion. Therefore, the kidneys are the central organs for the excretion of water and waste products.