Place the events of muscle contraction in the proper order from start (receiving signal) to the end (relaxation). ACH=Acetylcholine; SR=Sarcoplasmic Reticulum (Number 1-9)
Myosin heads pull actin filaments together with the sarcomeres and the cell shortens.
ATP is used to detach myosin heads and move them back to position for another power stroke.
Myosin Heads bind to actin forming cross bridges.
Muscle relaxes when stimulation ends and the calcium is pumped back into the SR.
The SR releases calcium into the cytoplasm.
ACH binds to the muscle's motor end plate and produces an action potential
Calcium shifts troponin and tropomyosin so that binding sites on actin are exposed.
The action potential travels to sarcoplasmic reticulum (SR).
Acetylcholine (ACH) is released from neuron ending in the synaptic cleft at the neuromuscular junction.