The main organs of the muscular system?

Skeletal muscles are attached to bones and are responsible for voluntary movement. They are composed of bundles of muscle fibers, which are elongated, cylindrical cells that contain specialized proteins that allow them to contract. Skeletal muscles are innervated by nerves from the central nervous system, which send signals to the muscles to cause them to contract.

Cardiac muscle is found in the heart and is responsible for pumping blood throughout the body. It is composed of specialized muscle fibers that are interconnected by intercalated discs, which allow them to contract in a coordinated manner. Cardiac muscle is innervated by the autonomic nervous system, which sends signals to the heart to increase or decrease its rate of contraction.

Smooth muscle is found in the walls of internal organs, such as the stomach, intestines, and blood vessels. It is composed of spindle-shaped muscle fibers that are not striated, and it is innervated by the autonomic nervous system. Smooth muscle contracts to move substances through internal organs or to regulate the flow of blood through blood vessels.