Cardiac Anatomy and Physiology Flashcards

A rhythm analysis technician observes a patient's EKG. The electrical impulse originates in the SA node, travels through the atria, and is then delayed at the AV node. What is the next structure the impulse will travel to in the normal conduction pathway?

Answer: Bundle of His

Following the delay at the atrioventricular (AV) node, the electrical impulse travels to the Bundle of His. From there, it moves to the right and left bundle branches and finally to the Purkinje fibers, which causes ventricular contraction.

Which heart valve is responsible for preventing the backflow of oxygenated blood from the left ventricle into the left atrium?

Answer: Mitral valve

The mitral valve, also known as the bicuspid valve, is located between the left atrium and the left ventricle. Its function is to close during ventricular contraction (systole) to prevent blood from flowing back into the left atrium.

A patient is experiencing a blockage in the right coronary artery (RCA). Which of the following structures is most likely to be affected?

Answer: SA node and right ventricle

The right coronary artery (RCA) supplies blood to the right atrium, right ventricle, and, in most individuals, the sinoatrial (SA) node and the atrioventricular (AV) node. A blockage in the RCA can therefore impact the heart's primary pacemaker and the right-sided chambers.

During which phase of the cardiac cycle do the ventricles contract, forcing blood into the aorta and pulmonary artery?

Answer: Systole

Systole is the period of the cardiac cycle when the heart muscle contracts. Specifically, ventricular systole is when the ventricles contract, pushing blood into the major arteries. Diastole is the period of relaxation and filling.

Which of the following correctly describes the function of the Purkinje fibers?

Answer: To rapidly transmit electrical impulses to the ventricular myocardium, causing coordinated contraction.

The Purkinje fibers are a network of specialized cells that rapidly conduct the electrical impulse from the bundle branches to the ventricular muscle cells. This rapid transmission ensures a coordinated and efficient contraction of the ventricles.

On an EKG, the depolarization of the atria, which leads to their contraction, is represented by which waveform?

Answer: P wave

The P wave on an electrocardiogram (EKG) represents atrial depolarization. This electrical activity originates in the SA node and spreads across the atria, causing them to contract and pump blood into the ventricles.