What is the main function of skeletal muscles?

The main function of skeletal muscles is to move the body. Skeletal muscles are attached to bones via tendons and are responsible for voluntary movements, which allows an individual to perform a wide variety of actions, from simple movements like walking and running to complex athletic maneuvers. These muscles contract in response to signals from the nervous system, enabling movement of the skeleton and providing the ability to control and coordinate movements in space.

While skeletal muscles do contribute to other functions, such as heat production and postural support, their primary role is indeed movement. The other options relate to functions that are either not primarily associated with skeletal muscles or are more relevant to other systems in the body. For example, regulating heart rate is a function of cardiac muscle, which operates involuntarily, and protecting internal organs is more the role of the skeletal structure or smooth muscles related to organ function rather than skeletal muscles. Additionally, while muscles do play a role in energy metabolism, they are not primarily storage sites for energy; that role is more accurately associated with adipose tissue and liver glycogen stores.