Which term describes the heart in a ready state to contract but not yet contracting?

• A. Depolarization
• B. Polarization
• C. Repolarization
• D. Ischemia

Answer: (B)

Polarization is the resting, ready-to-fire state of heart muscle cells. In this state, the inside of the cell is negatively charged compared with the outside, keeping the myocardium prepared to respond to an electrical impulse. When stimulation arrives, the cells depolarize, meaning positively charged ions rush in and the cell becomes less negative, leading to contraction. After contraction, the cells repolarize as ions move to restore the negative resting potential. Ischemia is a lack of blood flow that can damage cells and disrupt electrical activity, not the ready-to-contract state.