This session discusses the physiological mechanisms behind skeletal muscle contraction, focusing on the roles of motor neurons, neuromuscular junctions, and the excitation-contraction coupling process. The session explores the molecular basis of muscle contraction, including the roles of calcium ions, ATP, and the actin-myosin interaction. Clinically, understanding these mechanisms is crucial for diagnosing muscle-related conditions such as muscular dystrophies, myopathies, and disorders affecting neuromuscular transmission. Practical applications also extend to anesthetic practices, physical therapy, and the management of conditions like muscle cramps, fatigue, and spasticity.