what initiates a nerve impulse
The nerve impulse causes the release of acetylcholine from the motor end plate. This causes the depolarization of the membrane of the adjacent muscle cell. Depolarization trig â¦ gers the release of calcium ions from the sarcoplasmic reticulum inside the muscle cell.t is the firing of a nerve which sends an electrical signal down  the axons of that nerve. The message propagates by the movement of  Sodium (Na) and Potassium (K) ions in â¦ and out of the axon  wall/sheath.