Depolarization of a Cardiac Muscle Cell Occurs as the Result

Multiple Choice

Depolarization of a cardiac muscle cell occurs as the result of

A) a decrease in the permeability of the cell membrane to sodium.
B) the opening of voltage-gated sodium channels and voltage-gated calcium channels.
C) the closure of voltage-gated calcium channels.
D) the opening of voltage-gated potassium channels.
E) the closure of the voltage-gated sodium channels.