A review of skeletal muscle fiber (cell) contraction physiology using interactive animations and diagrams.
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.