Which muscle type is found in the heart and is involuntary?

• A. Skeletal Muscle
• B. Smooth Muscle
• C. Cardiac Muscle
• D. Involuntary Muscle

Answer: (C)

Cardiac muscle is the heart’s muscle tissue. It’s unique because it has the striped, sarcomere-based look of skeletal muscle but functions involuntarily, without conscious control. Heart contractions must be rhythmic and coordinated, and that coordination comes from intercalated discs that connect cardiac cells and allow electrical impulses to spread rapidly, plus pacemaker cells that set the rhythm with autonomic nervous system modulation. Smooth muscle is found in the walls of hollow organs and is also involuntary, but it isn’t in the heart. Skeletal muscle is voluntary and attaches to bones. So the muscle type in the heart that is involuntary is cardiac muscle.