Which of the following is NOT listed as a function of muscles?

• A. Assist in movement of cardiovascular veins and lymph
• B. Regulate digestion
• C. Protect internal organs and stabilize joints
• D. Support the body

Answer: (B)

Muscles have roles that keep the body moving, stable, and protected. They contract to pull on bones for movement, help maintain posture, cushion and support internal organs, and contribute to returning blood and lymph through the body via the muscle pumps around vessels. Digestion, on the other hand, is governed mainly by the smooth muscle of the digestive tract and by nervous/hormonal control that coordinates peristalsis and sphincter function. Those processes belong to the digestive system rather than being a primary listed function of the muscular system. So the statement about regulating digestion isn’t considered a standard muscular function, even though some muscles are involved in activities that touch the digestive process (like swallowing). The other options illustrate classic muscular roles: aiding venous/lymphatic return, protecting organs and stabilizing joints, and supporting body posture.