A certain kind of cardiac cell's shift in membrane potential is seen using specialized electrodes. The graph below shows these modifications. The deflection indicated by the arrow is most likely caused by movement of which of the following ions?

Question

A certain kind of cardiac cell's shift in membrane potential is seen using specialized electrodes. The graph below shows these modifications.  The deflection indicated by the arrow is most likely caused by movement of which of the following ions?

Quizplus · Accepted Answer

Eductional Objective: Phase 0 depolarization in cardiac pacemaker cells is mediated by an inward calcium flow. This is distinct from phase 0 of Purkinje cells and cardiomyocytes, which is brought on by an inward sodium current.

A Certain Kind of Cardiac Cell's Shift in Membrane Potential