What is the excretory system?

• A. System that regulates hormones
• B. System that removes waste
• C. System that allows movement
• D. System that breaks down food

Answer: (B)

The excretory system is the body's waste-removal and balance-maintaining system. It filters and eliminates metabolic wastes produced by cells, such as urea, and helps regulate water and electrolyte levels to keep the body's internal environment stable. Important parts include the kidneys, which filter blood to form urine; the lungs, which expel carbon dioxide; the skin, which releases sweat; and the liver and digestive tract, which help process and remove other wastes. This makes excretion its primary role: removing waste from the body. It isn’t about regulating hormones (that’s the endocrine system), enabling movement (that’s the musculoskeletal system), or breaking down food (that’s the digestive system).