Cоmplete eаch sentence belоw tо demonstrаte your understаnding of the initiation and spread of action potentials through the heart. 1. The depolarization of the [q1] normally generates the action potential that leads to depolarization of all other cardiac muscle cells. 2. Thus, the discharge rate of this group of cells determines the [q2] 3. The action potentials initiated in the heart passes from cell to cell by way of [q3] 4. Depolarization first spreads through muscle cells of the [q4] , with conduction rapid enough that both contract at essentially the same time. 5. this is signified as the [q5] on an ECG 6. Next, the depolarization slowly travels through the [q6] , which is the link between atrial and ventricular depolarization. 7. After leaving this region, the action potential enters a region of the muscular wall known as the [q7] 8. Within this wall are conducting-system pathways called the [q8] , which divide into the right and left bundle branches that separate at the bottom of the heart and enter the walls of both ventricles. 9. These fibers make contact with [q9] which are large-diameter conducting cells that rapidly distribute the action potential throughout much of the ventricles. 10. The resulting ventricular depolarization is signified as the [q10] on an ECG recording. 11. Finally, ventricular cells undergo repolarization, which is signified as the [q11] on an ECG recording.