In this video, we differentiate between SA node action potential and ventricular action potential.
SA node action potential is responsible for automaticity of heart. It consists of 3 phases : phase 4, phase 0 and phase 3.
Phase 4 is due to: Hyperpolarization gated cyclic nucleotide channels (HCN channels) and T type voltage gated calcium channels.
Phase 0 is due to opening of L type voltage gated calcium channels and entry of calcium inside the cells
Phase 3 is due toopening of voltage gated potassium channels and exit of potassium from the cells.
(Where are phases 1 and 2 ?) 😮
Phase 4 is also known as prepotential or pacemaker potential. The slope of the phase 4 determines the number of impulses which are generated in 1 minue. Steeper slope means more impulses, less steep slope means less impulses.
SA node action potential is responsible for automaticity of heart. It consists of 3 phases : phase 4, phase 0 and phase 3.
Phase 4 is due to: Hyperpolarization gated cyclic nucleotide channels (HCN channels) and T type voltage gated calcium channels.
Phase 0 is due to opening of L type voltage gated calcium channels and entry of calcium inside the cells
Phase 3 is due toopening of voltage gated potassium channels and exit of potassium from the cells.
(Where are phases 1 and 2 ?) 😮
Phase 4 is also known as prepotential or pacemaker potential. The slope of the phase 4 determines the number of impulses which are generated in 1 minue. Steeper slope means more impulses, less steep slope means less impulses.
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