4

finally, the muscle fiber returns to its resting ___

length

relaxation begins when nerve signals quit stimulating the synaptic knob from releasing ___

acetylcholine

active trnaport pumps in the SR move ___ back into the cisternae

calcium

acetylcholine dissociates from its ___ and no new moleciles of acetylcholine are released

receptor

___ moves back into position blocking active sites and no more contractions can occur

tropomyosin