The muscular system is responsible for movement of the body, maintenance of posture, and production of heat. Muscles work in coordination with the skeletal system to facilitate locomotion.
Muscles are classified into three main types:
Skeletal muscle consists of muscle fibers containing myofibrils. Myofibrils are composed of actin and myosin filaments arranged in repeating units called sarcomeres.
Muscle contraction occurs through the sliding filament mechanism, where actin and myosin filaments slide over each other using energy derived from ATP.
The neuromuscular junction is the site where a motor neuron communicates with a muscle fiber, leading to muscle contraction.