Which system allows for voluntary and involuntary movement of the body?

• A. Digestive System
• B. Muscular System
• C. Lymphatic System
• D. Nervous System

Answer: (B)

Movement is produced by muscles, and this system handles both deliberate and automatic actions. Skeletal muscles let you move parts of your body on command (voluntary movement), while smooth muscles in organs and blood vessels and cardiac muscle in the heart execute automatic, involuntary contractions. The nervous system signals muscles to contract, but the actual act of moving comes from the muscular system itself. The digestive, lymphatic, and nervous systems play supporting roles—digestive moves contents through tubes, the lymphatic system transports lymph, and the nervous system coordinates actions—yet they don’t directly generate movement in the way muscles do.