ESIM - Evaporative System Integrity Monitor, All Acronyms, viewed April 16, 2017, <https://www.allacronyms.com/ESIM/Evaporative_System_Integrity_Monitor>.
Acetylcholine is the neurotransmitter used at the neuromuscular junction âin other words, it is the chemical that motor neurons of the nervous system release in order to activate muscles.
So letâs do a quick review of muscle contraction physiology: 1  An action potential in a motor neuron causes acetylcholine to release in the synaptic cleft. 2  Acetylcholine binds with receptors on the cell membrane on the muscle fiber, opening Ca2+ -Na+ channels. Usually referred to as Calcium channels.