A review of skeletal muscle fiber (cell) contraction physiology using interactive animations and diagrams. Learn more with quizzes and labelling exercises.
In skeletal muscle fibers, electrochemical activity triggers myofilament movement. These linked events are referred to as excitation-contraction coupling.
As the action potentials travel down the T tubules, calcium channels in the nearby terminal cisternae of SR open, and Ca2+ ions diffuse into the surrounding sarcoplasm. The Ca2+ ions bind to troponin proteins embedded along the thin filaments and the contraction process begins.