GROSS ANATOMY

Detailed explanation-1: -The electrical impulse travels from the sinus node to the atrioventricular node (also called AV node). There, impulses are slowed down for a very short period, then continue down the conduction pathway via the bundle of His into the ventricles.

Detailed explanation-2: -Each impulse travels through internodal pathways in the right and left atria and depolarizes the myocardial cells, causing the muscle in the atrium to contract. From the SA node in the atria, an electrical impulse travels to the atrioventricular node (AV node).

Detailed explanation-3: -After passing through the AV node, the electrical current then continues down the conduction pathway, through a pathway called the bundle of His, and into the ventricles. The bundle of His divides into right and left pathways (bundle branches) to give electrical stimulation to the right and left ventricles.