EKG certification Certification EKG Cardiac Anatomy & Physiology 3

Question 1

What is the primary function of the Purkinje fibers in cardiac conduction?

Accepted Answer

Rapidly distribute electrical impulses throughout the ventricles

Answer

Purkinje fibers rapidly transmit electrical impulses throughout the ventricular myocardium to ensure coordinated contraction from the apex upward.

Question 2

Which EKG wave represents atrial depolarization?

Accepted Answer

P wave

Answer

The P wave on an EKG represents the electrical depolarization spreading through the right and left atria.

Question 3

The interventricular septum receives its blood supply primarily from which coronary artery?

Accepted Answer

Left anterior descending artery

Answer

The left anterior descending artery supplies the anterior two-thirds of the interventricular septum through its septal perforating branches.

Question 4

What percentage of cardiac output at rest is ejected with each ventricular contraction (ejection fraction)?

Accepted Answer

55% to 70%

Answer

A normal resting ejection fraction is 55% to 70%, indicating the percentage of blood pumped out of the left ventricle with each contraction.

Question 5

Which structure prevents the backflow of blood from the aorta into the left ventricle?

Accepted Answer

Aortic valve

Answer

The aortic semilunar valve closes after ventricular systole to prevent blood from flowing back into the left ventricle.

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