What are considered voluntary muscles in the human body?

Voluntary muscles are those that can be consciously controlled by an individual. These muscles are primarily responsible for movements such as lifting, walking, or any other actions that require deliberate coordination. Arm and leg muscles, also known as skeletal muscles, fit this definition perfectly. They are attached to bones and allow for movement in response to commands from the nervous system.

In contrast, the other options reflect muscle types that do not operate under conscious control. Heart muscles, known as cardiac muscles, function involuntarily to pump blood throughout the body. Involuntary muscles refer to muscles that operate without conscious thought, such as those found in the walls of organs. Lastly, smooth muscles, which are also involuntary, control movements within internal organs like the digestive tract. These muscle types perform essential functions, but their operation is not within the conscious control of an individual. Thus, the arm and leg muscles are specifically the voluntary muscles that allow for intentional movement.