Cardiovascular The System: Cardiac Action Potential 1. How do the waves of depolarization, generated by the autorhythmic cells spread to the muscle cells? _____________________. 2. 3. Depolarizing current from the autorhythmic cells causes the ventricular muscle cells to ____________. Name the 3 channels essential for generating an action potential and indicate which way the ions move (circle the correct one): a. ______________ channels b. ______________ channels c. ______________ channels 4. into into into or or or out of out of out of
If the sodium channel or the fast calcium channels are open, the inside of the cell would be relatively more ____________.
5.
The pacemaker potential is due to a/an (decreased or increased) efflux of ____ ions compared to a normal influx of ____ ions.
6.
Threshold for the action potential in the SA Node is at ____ mV. What channels open, causing depolarization? _________________
7.
The of reversal membrane potential causes the _____ channels to open, causing the _________________ of the membrane.
8.
The ______________ pumps sodium out and potassium into the cell, restoring ion concentrations to their resting levels.
9. 10.
Where is calcium stored in the contractile cells? ________________ Gap junctions allow what cations to pass into the cardiac contractile cells, causing the opening of voltagegated sodium channels? ________________________
11.
State the voltage-gated channels responsible for the following stages of the action potential in cardiac contractile cells: a. Depolarization ______________________ b. Plateau ______________________
c. Repolarization ______________________ 12. What channels in the autorhythmic cells allow ions to leak in, producing a pacemaker potential? (Quiz section) ______________ 13. What channels in the autorhythmic cells bring about depolarization? _____________.