Muscle Fiber Physiology
Input from nervous system starts contraction.
Neurotransmitter is acetylcholine [Ach]
Calcium ions released due to action potential [stimulus that causes change of membrane permeability]
Calcium causes release of Ach from synaptic vesicles - which causes release of sodium, enhancing cell permeability and action potential.
Ach is rapidly broken down by acetylcholinesterace - and choline /acetic acid is recycled.
Action potential causes muscle contraction = excitation/contraction coupling