3. Describe the pathway that depolarization takes as it travels through the heart.

The wave of depolarization begins in the right atrium, and the impulse spreads across the superior portions of both atria and then down through the contractile cells. The contractile cells then begin contraction from the superior to the inferior portions of the atria, efficiently pumping blood into the ventricles.

Answer:Depolarisation occurs when the nerve cells reverses their charges.

Explanation:Depolarization occurs in the four chambers of the heart. Both atria first and both ventricles. The sinoatria (SA) node on the wall of the right atrium initiates Depolarization in the right and left atria, causing contraction, which is symbolized by the P wave on an electrocardiogram.