Which type of muscle is responsible for involuntary movements?

The correct answer is that both smooth muscle and cardiac muscle are responsible for involuntary movements.

Smooth muscle is found in the walls of hollow organs such as the intestines, blood vessels, and the bladder. It operates autonomously and is not under conscious control, meaning it contracts and relaxes without deliberate effort from the individual. This is crucial for processes such as digestion and regulating blood flow.

Cardiac muscle, which makes up the heart, also functions involuntarily. It is responsible for pumping blood throughout the body and operates rhythmically and continuously without conscious input. Like smooth muscle, cardiac muscle contractions are regulated by the autonomic nervous system, ensuring the heart's steady rhythm and function.

In contrast, skeletal muscle is responsible for voluntary movements and is typically under conscious control, allowing for actions like walking or lifting. Therefore, while skeletal muscle functions intentionally, both smooth and cardiac muscle play essential roles in involuntary functions necessary for survival.