MEDICAL PHYSIOLOGY

Detailed explanation-1: -Located in the interatrial septum, the AV node conducts electrical impulses from the SA node to the heart ventricles. This is achieved via atrioventricular bundles (a.k.a. bundle of His) and subendocardiac conducting network/Purkinje fibers located in the ventricle walls.

Detailed explanation-2: -Next, the signal travels to the AV node, through the bundle of HIS, down the bundle branches, and through the Purkinje fibers, causing the ventricles to contract. This signal creates an electrical current that can be seen on a graph called an electrocardiogram, or EKG.

Detailed explanation-3: -The sinus node generates an electrical stimulus regularly, 60 to 100 times per minute under normal conditions. The atria are then activated. The electrical stimulus travels down through the conduction pathways and causes the heart’s ventricles to contract and pump out blood.

Detailed explanation-4: -In the ventricles, action potentials travels along the interventricular septum to the apex of the heart, then spread up the endocardial surface of the walls of the ventricles. Purkinje fibers conduct action potentials to ventricular myocardial cells.