An action potential, abbreviated AP, is a generalized [[Zellmembran/en|membrane]] [[Depolarisation/en|depolarization]] of a [[Zelle/en|cell]].
An action potential, abbreviated AP, is a generalized [[Zellmembran/en|membrane]] [[Depolarisation/en|depolarization]] of a [[Zelle/en|cell]].
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The [[Membranpotential/en|membrane potential]] reaches a threshold value due to changes in the [[Ion/en|ion]] fluxes by extracellular chemical or physical signals or by intracellular metabolic processes.
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The [[Membranpotential/en|membrane potential]] reaches a threshold value due to changes in the [[Ionen/en|ion]] fluxes by extracellular chemical or physical signals or by intracellular metabolic processes.
In the heart, the AP appears at the pacemaker cells, the [[Purkinje fibers]] and the working [[Herzmuskel/en|myocardium]], where it initiates [[Kontraktion/en|contraction]]. The AP of the heart muscle cells differs from the AP of the [[Nervenzellen/en|nerve cells]] by a pronounced plateau as a result of a strong [[Calcium/en|calcium]] influx that begins with depolarization.
In the heart, the AP appears at the pacemaker cells, the [[Purkinje fibers]] and the working [[Herzmuskel/en|myocardium]], where it initiates [[Kontraktion/en|contraction]]. The AP of the heart muscle cells differs from the AP of the [[Nervenzellen/en|nerve cells]] by a pronounced plateau as a result of a strong [[Calcium/en|calcium]] influx that begins with depolarization.
The membrane potential reaches a threshold value due to changes in the ion fluxes by extracellular chemical or physical signals or by intracellular metabolic processes.
In the heart, the AP appears at the pacemaker cells, the Purkinje fibers and the working myocardium, where it initiates contraction. The AP of the heart muscle cells differs from the AP of the nerve cells by a pronounced plateau as a result of a strong calcium influx that begins with depolarization.