Cardiac Anatomy & Physiology Flashcards

Which branch of the left coronary artery supplies the lateral wall of the left ventricle?

Answer: Left circumflex (LCx)

The left circumflex artery travels in the left atrioventricular groove and supplies the lateral and posterior left ventricular wall via obtuse marginal branches.

In the context of Laplace's law applied to the heart, wall stress is increased by:

Answer: Increased ventricular radius and decreased wall thickness

Laplace's law states wall stress = (pressure × radius) / (2 × wall thickness); larger radius and thinner walls increase wall stress.

The 'v' wave in a pulmonary capillary wedge pressure (PCWP) tracing reflects:

Answer: Passive venous filling of the atrium during ventricular systole

The 'v' wave represents the rise in left atrial pressure as the pulmonary veins fill the atrium while the mitral valve is closed during ventricular systole.

Which coronary artery typically supplies the AV node?

Answer: Right coronary artery in right-dominant systems

In right-dominant systems (approximately 85% of individuals), the AV nodal artery arises from the RCA at the crux of the heart.

Ejection fraction (EF) is calculated as:

Answer: End-diastolic volume minus end-systolic volume divided by end-diastolic volume

EF = (EDV – ESV) / EDV × 100%; it represents the fraction of end-diastolic volume ejected with each beat.

Which anatomical feature distinguishes the right ventricle from the left ventricle on cross-section?

Answer: Crescent/triangular shape and thinner wall with trabeculations

The right ventricle has a crescent-shaped, thin-walled cavity with coarse trabeculations, adapted for low-pressure pulmonary circulation.

The normal QRS duration reflects conduction through which cardiac structures?

Answer: Bundle of His, bundle branches, and Purkinje fibers to ventricular myocardium

The QRS complex represents ventricular depolarization, encompassing conduction through the His-Purkinje system and ventricular muscle.