GROSS ANATOMY

Detailed explanation-1: -Step 3: AV Bundle Impulse Conduction This bundle of fibers branches off into two bundles and the impulses are carried down the center of the heart to the left and right ventricles.

Detailed explanation-2: -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-3: -Initially, the right bundle branch off of the bundle of His travels down the interventricular septum near the endocardium. It then dives deeper into the muscular layer before re-emerging near the endocardium again. The right bundle branch receives most of its blood supply from the anterior descending coronary artery.

Detailed explanation-4: -The Purkinje fibers conduct the impulse throughout the right and left ventricles. As the action potential travels through the bundle of His, the bundle branches, and the Purkinje fibers, the ventricular contractile myocytes depolarize and contract. The heart is now in systole.