What type of wave is primarily responsible for the depolarization of the atria?

The P wave is primarily responsible for the depolarization of the atria in the heart's electrical conduction system. During this phase, the electrical impulses travel through the sinoatrial (SA) node located in the right atrium, prompting the atria to contract and pump blood into the ventricles. This process of depolarization indicates that the atrial muscles are being electrically stimulated, which is vital for maintaining an effective heartbeat and ensuring proper circulation.

The morphology of the P wave on an electrocardiogram reflects this atrial depolarization and is typically seen as a small, rounded wave preceding the larger QRS complex, which represents ventricular depolarization. By analyzing the P wave, healthcare professionals can assess the rhythm and rate of atrial activity, which is critical for diagnosing various cardiac conditions.