Heart part 2

Are you here?

• yes

• no

The ___ is the heart's pacemaker

• sinoatrial node

• atrioventricular node

• atrioventricular bundle

• purkinje fibers

In nodal cells, depolarization is due to opening of

• voltage gated sodium channels

• voltage gated calcium channels

• voltage gated potassium channels

• chemically gated sodium channels

During the _____ phase of the cardiac action potential, slow voltage gated calcium channels open and calcium enters the cell.

• depolarization

• plateau

• depolarization

• resting

The atrioventricular valves are open during which phases of the cardiac cycle? (choose all that apply)

• atrial contraction and ventricular filling

• isovolumetric contraction

• ventricular ejection

• isovolumetric relaxation

• atrial relaxation and ventricular filling

The semilunar valves are open during which phase of the cardiac cycle?

• atrial contraction and ventricular filling

• isovolumetric contraction

• ventricular ejection

• isovolumetric relaxation

• atrial relaxation and ventricular filling

Pressure in the ventricles is highest during which phase of the cardiac cycle?

• atrial contraction and ventricular filling

• isovolumetric contraction

• ventricular ejection

• isovolumetric relaxation

• atrial relaxation and ventricular filling