Which statement best describes the phase of the cardiac cell cycle described as polarization, preparing for discharge?

• A. Depolarization
• B. Repolarization
• C. Resting state
• D. Polarization of the cell, preparing it for discharge

Answer: (D)

Before a cardiac cell fires, its membrane is polarized, meaning the inside is negatively charged compared with the outside. This resting membrane potential primes the cell to respond to a stimulus. When a trigger arrives, the cell depolarizes as sodium rushes in, producing the actual discharge (the action potential). Afterward, repolarization restores the negative interior, returning the cell to its polarized, ready-to-fire state. So describing polarization as the cell’s state preparing for discharge fits the pre-fire, ready state. The other terms describe the discharge itself (depolarization) or the return to baseline after discharge (repolarization).