CCT Cardiac Anatomy & Physiology 5

Question 1

Which of the following best defines 'afterload' in cardiac physiology?

Accepted Answer

The resistance the ventricle must overcome to eject blood

Answer

Afterload is the resistance or wall stress that the ventricle must overcome during systole to eject blood, primarily determined by systemic vascular resistance for the left ventricle.

Question 2

In a dominant right coronary circulation, the RCA gives rise to which critical branch supplying the inferior wall?

Accepted Answer

Posterior descending artery (PDA)

Answer

In right-dominant circulation (about 70% of people), the RCA gives rise to the posterior descending artery, which supplies the inferior wall of the left ventricle and posterior third of the interventricular septum.

Question 3

Which ion is primarily responsible for the plateau phase (phase 2) of the cardiac action potential?

Accepted Answer

Calcium (Ca2+)

Answer

During phase 2 (plateau), slow L-type calcium channels open and Ca2+ influx balances K+ efflux, prolonging depolarization and triggering myocardial contraction via excitation-contraction coupling.

Question 4

The 'a' wave seen in the jugular venous pulse (JVP) corresponds to which cardiac event?

Accepted Answer

Atrial contraction

Answer

The 'a' wave of the JVP reflects atrial contraction, which increases right atrial pressure and is transmitted back into the jugular veins just before ventricular systole.

Question 5

Which wall of the left ventricle is most commonly affected in an occlusion of the left circumflex artery?

Accepted Answer

Lateral wall

Answer

The left circumflex artery supplies the lateral wall of the left ventricle; its occlusion typically produces a lateral myocardial infarction with ST changes in leads I, aVL, V5, and V6.

(CCT) Certified Cardiac Technician Practice Test

(CCT) Certified Cardiac Technician Practice Test

CCT Cardiac Anatomy & Physiology 5