I need help putting these steps in order.

Ca2+ pumps restore Ca2+ to SR → relaxation!

Action potential travels down the axon in response to nerve stimulus.

Myosin binds to actin

Action potential causes Ca2+ release from SR

Myosin pulls actin chain along and Sarcomere shortens → contraction!

Action potential travels down the T Tubule and into Sarcoplasmic Reticulum (SR)

Ca2+ binds to troponin. Troponin moves tropomyosin uncovering myosin binding site on actin