GROSS ANATOMY

Detailed explanation-1: -The Q and S waves are downward waves while the R wave, an upward wave, is the most prominent feature of an ECG. The QRS complex represents action potentials moving from the AV node, through the bundle of His and left and right branches and Purkinje fibers into the ventricular muscle tissue.

Detailed explanation-2: -After the signal leaves the AV node it travels along a pathway called the bundle of His (3) and into the right and left bundle branches (4, 5). The signal travels across the heart’s ventricles causing them to contract, pumping blood to the lungs and the body. This signal is recorded as the QRS waves on the ECG.

Detailed explanation-3: -The three waves of the QRS complex represent ventricular depolarization.

Detailed explanation-4: -The J point in the ECG is the point where the QRS complex joins the ST segment. It represents the approximate end of depolarization and the beginning of repolarization as determined by the surface ECG.