Which feature of cardiac tissue allows for the rapid spread of action potentials through the heart?

Mark the following statements as true or false. If a statement is false, correct it to make a true statement.

e. The heart plays a role in the regulation of blood pressure and secretes the hormone atrial natriuretic peptide.

The ______is the primary pacemaker of the heart.

a. atrioventricular node

b. sinoatrial node

c. Purkinje fiber system

d. atrioventricular bundle

The AV node delay:

a. allows the atria and ventricles to depolarize and contract as a unit.

b. allows the two ventricles to depolarize and contract separately.

c. allows the atria and ventricles to depolarize and contract separately.

d. speeds up the impulse transmission from the atria to the ventricles.

A newer drug, Ivabradine, lowers the heart rate by blocking the nonselective HCN cation channels. Why would this action decrease the heart rate? Would this drug have an effect on pacemaker cells, contractile cells, or both? Explain.

Which statement best describes intrinsic conduction of the heart?

The intrinsic conduction system ensures a coordinated and efficient heartbeat. If the sinoatrial (SA) node malfunctions, which part of the heart’s conduction system is most likely to take over as the pacemaker?

Which answer choice below correctly matches the cardiac conduction structure to where it’s found in the heart?

The AV node has fewer gap junctions than the SA node, leading to slower conduction. How does this slower conduction help the heart function?