Skeletal muscle responds to nervous signals by contracting and relaxing in a coordinated manner, which results in movement. When a nerve impulse, or action potential, travels to a skeletal muscle fiber, it triggers the release of a chemical called acetylcholine from the nerve ending. Acetylcholine then binds to receptors on the muscle fiber, causing the muscle to contract.
The process of muscle contraction begins with the sliding of thin filaments called actin and myosin past each other. The myosin filaments have small, knob-like structures called cross-bridges that bind to the actin filaments and pull them along, causing the muscle fiber to shorten. As the muscle fiber shortens, it generates force, which can be used to move the body or an external object.
When the nervous signal to the muscle is turned off, the muscle relaxes and the actin and myosin filaments return to their original positions. This process allows skeletal muscles to respond to nervous signals and produce movement in a controlled and coordinated manner.