Relier Pairs Skeletal Muscle ContractionVersion en ligne Match the various steps of a skeletal muscle contraction with the descriptions of that action. par Lindsay Spielman 1 End Plate Potential 2 Acetylcholinesterase 3 Muscle relaxation 4 Toponin 5 Calcium release by the SR 6 Directly causes cross-bridge detachment 7 Tropomyosin 8 Acetylcholine 9 Directly causes cross bridge formation Calcium binds to this regulatory protein on the thin filaments. Degrades acetylcholine in the synapse. ATP attaches to the myosin head. Regulatory protein that covers the myosin-binding sites of the actin. Neurotransmitter released by somatic neurons at the neuromuscular junction. Triggered by depolarization of the t-tubules. Calcium is actively pumped back into the SR. Hydrolysis of ATP to ADP and Pi by the ATPase of the myosin head. Local sarcolemma depolarization of the neuromuscular junction.