Cardiac Anatomy and Physiology Flashcards

The chordae tendineae attach the leaflets of the AV valves to which cardiac structures?

Answer: Papillary muscles

Chordae tendineae are fibrous cords that connect the AV valve leaflets to the papillary muscles, preventing leaflet prolapse during ventricular systole.

Which layer of the heart wall contains the cardiac muscle cells (cardiomyocytes)?

Answer: Myocardium

The myocardium is the middle and thickest layer of the heart wall composed of cardiac muscle cells responsible for the pumping action.

The coronary sinus drains primarily into which cardiac chamber?

Answer: Right atrium

The coronary sinus is the main venous drainage vessel of the heart and empties directly into the right atrium near the inferior vena cava.

During isovolumetric contraction, which valves are CLOSED?

Answer: All four valves are closed

During isovolumetric contraction, ventricular pressure rises but no blood is ejected; all four valves remain closed until ventricular pressure exceeds great vessel pressure.

The P-wave on a standard ECG corresponds to which mechanical event?

Answer: Atrial depolarization

The P-wave represents the electrical depolarization of the atria, which precedes and triggers atrial contraction.

Which of the following best describes the Frank-Starling mechanism?

Answer: Greater ventricular end-diastolic volume produces greater stroke volume

The Frank-Starling law states that within physiological limits, increased stretch of cardiac muscle fibers (higher preload) results in a more forceful contraction and greater stroke volume.

The right coronary artery most commonly supplies the sinoatrial node in what percentage of the population?

Answer: 55%

In approximately 55–60% of individuals the SA node artery arises from the right coronary artery, making RCA occlusions a common cause of sinus node dysfunction.