How does an action potential in a motor neuron cause actin and myosin filaments to slide together? ?

Contraction is initiated by depolarization of the sarcolemma. The action potential spreads inside along the T-tubules. The signal is transmitted from T-tubule to terminal sacs of sarcoplasmic reticulum(SR). Calcium is released from (SR) into sarcoplasm.

The binding of Ca2+ to troponin results in a cooperative conformational change in the troponin-tropomyosin system. The inhibition of actin and myosin interaction is released. Crossbridges of myosin filaments are attached to actin filaments and ATP is then used causing the actin and myosin to interact resulting in the shortening of the sarcomeres.

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