Flashcards in Terminology Deck (11):
Functional refractory period
The coupling interval which first results in a measurable degree of delay in impulse conduction
Effective refractory period
The longest coupling intervals to be associated with block
Resting transmembrane potential
Voltage difference between the inside and outside of the cell fiber
Cellular characteristics of depolarization and repolarization. The action potential consist of five phases
Definition of phase 0 of action potential
The depolarization phase, during this phase the rapid sodium channels are stimulated to open, causing the resting transmembrane potential to spike from -90 mV to 20 mV
Definition of phase 1 of the action potential
Definition ofPhase 2Of the action potential
The plateau phase. This phase, mediated by the slow calcium channels, essentially disrupts and delays the repolarization started in phase 1 and prolongs the refractory period
Definition of phase 3 of the action potential
The end of repolarization.
Which phases of the action potential represent the refractory period of cardiac tissue?
The end of phase 0 through the end of phase 3 represents the refractory period Of cardiac tissue
Definition of phase 4 of the action potential
The resting phase. It is during this phase that and some cardiac cells ions lake back-and-forth between membranes and cause a gradual increase in the transmembrane resting potential. When the potential voltage reaches the threshold voltage the cell repolarizes.