The Long Plateau Phase of the Cardiac Muscle Action Potential

Question

The long plateau phase of the cardiac muscle action potential is due to
A) movement of fewer sodium ions across the cell membrane.
B) calcium channels remaining open.
C) increased membrane permeability to potassium ion.
D) decrease in the amount of calcium diffusing across the membrane.
E) increased membrane permeability to sodium ions.

Accepted Answer

The long plateau phase of the cardiac muscle action potential is due to calcium channels remaining open, which prolongs depolarization and maintains the contraction of the cardiac muscle.