Which is the neurotransmitter that causes the release of calcium ions from reservoirs within the muscle cell and thereby initiates the steps of contraction? acetylcholinesterase acetylcholine serotonin norepinephrine?

The neurotransmitter that causes the release of calcium ions from the muscle cell is the Acetycholine.                                                                                          Acetylcholine diffuses into the synaptic cleft and can bid to the nicotinic acetycholine receptors on the motor end plate, causing calcium ions to flow into the muscle cell intiating a sequence of steps that finally produce muscle contraction.