How do nerve impulses trigger the release of calcium ions

Can you elaborate on the physiological mechanisms underlying muscle contraction, including the role of calcium ions, ATP hydrolysis, and the sliding filament theory? How do nerve impulses trigger the release of calcium ions from the sarcoplasmic reticulum, leading to the exposure of myosin-binding sites on actin and the formation of cross-bridges between actin and myosin filaments? Additionally, how does ATP hydrolysis power the detachment of myosin heads from actin, allowing for muscle relaxation? Furthermore, how do factors such as muscle fiber type, motor unit recruitment, and muscle fiber length-tension relationship influence the force and velocity of muscle contraction?