CCI Cardiac Anatomy and Physiology 4

Question 1

The bundle of His bifurcates into the right and left bundle branches at which anatomical location?

Accepted Answer

Top of the muscular interventricular septum

Answer

The bundle of His travels through the fibrous AV septum and divides into right and left bundle branches at the crest of the muscular interventricular septum.

Question 2

Which great vessel arises from the right ventricle and carries deoxygenated blood?

Accepted Answer

Pulmonary artery

Answer

The pulmonary artery (main pulmonary trunk) originates from the right ventricular outflow tract and carries deoxygenated blood to the lungs for gas exchange.

Question 3

Ejection fraction (EF) is defined as:

Accepted Answer

Stroke volume divided by end-diastolic volume

Answer

Ejection fraction = stroke volume / end-diastolic volume × 100%; normal LV EF is ≥55%, and it reflects the percentage of blood ejected per beat.

Question 4

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

Accepted Answer

Calcium (Ca²⁺)

Answer

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

Question 5

The left circumflex artery typically supplies which portion of the left ventricle?

Accepted Answer

Lateral wall and posterior wall

Answer

The left circumflex artery courses in the left AV groove and typically supplies the lateral and posterior walls of the left ventricle via obtuse marginal branches.

CCI - Cardiovascular Credentialing International Practice Test

CCI - Cardiovascular Credentialing International Practice Test

CCI Cardiac Anatomy and Physiology 4