This is transmitted chemically, by the formation at nerve-endings of chemical substances. When, for example, a NERVE to a muscle is stimulated, there appears at the NEUROMUSCULAR JUNCTION the chemical substance, ACETYLCHOLINE. Acetylcholine also appears at endings of the parasympathetic nerves (see NERVOUS SYSTEM) and transmits the e?ect of the parasympathetic impulse. When an impulse passes down a sympathetic nerve, the e?ect of it is transmitted at the nerve-ending by the chemical liberated there: ADRENALINE or an adrenaline-like substance.... nervous impulse
the electrical activity in the membrane of a *neuron that – by its rapid spread from one region to the next – is the means by which information is transmitted within the nervous system along the axons of the neurons. The membrane of a resting nerve is charged (polarized) because of the different concentrations of ions inside and outside the cell. When a nerve impulse is triggered, a wave of *depolarization spreads, and ions flow across the membrane (see action potential). Until the nerve has undergone *repolarization no further nerve impulses can pass.... nerve impulse
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