The electrical depolarization which spreads through the heart musculature and precedes contraction of atria and ventricles is dependent upon the rapid inward diffusion of which of the following ions?

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Quizplus · Accepted Answer

The electrical depolarization in the heart musculature is caused by the rapid inward diffusion of calcium ions. This triggers the contraction of atria and ventricles. Sodium also plays a role in depolarization, but its contribution is secondary to that of calcium. Nitrate, chloride, and potassium are not involved in the electrical depolarization of the heart.

The Electrical Depolarization Which Spreads Through the Heart Musculature and Precedes