CET Cardiovascular Anatomy & Physiology 3 — Questions and Answers
Question 1: Which of the following best describes preload in cardiac physiology?
- Resistance the ventricle must overcome to eject blood
- Ventricular wall tension during contraction
- End-diastolic volume stretching the ventricular wall (Correct answer)
- Intrinsic contractility of cardiomyocytes
Correct answer: End-diastolic volume stretching the ventricular wall
Preload refers to the degree of ventricular wall stretch at end-diastole, related to end-diastolic volume and venous return.
Question 2: The sinoatrial (SA) node is located in which part of the heart?
- Interventricular septum
- Left atrial appendage
- Right atrium near the superior vena cava (Correct answer)
- Atrioventricular groove
Correct answer: Right atrium near the superior vena cava
The SA node sits in the posterior wall of the right atrium near the junction with the superior vena cava and serves as the primary pacemaker.
Question 3: Which segment of the cardiac cycle is characterized by rising ventricular pressure with all valves closed?
- Isovolumetric relaxation
- Isovolumetric contraction (Correct answer)
- Rapid ventricular filling
- Ejection phase
Correct answer: Isovolumetric contraction
Isovolumetric contraction occurs after mitral valve closure and before aortic valve opening, with no change in ventricular volume.
Question 4: On a standard 2D echocardiogram, the moderator band is a structure seen in which chamber?
- Left atrium
- Right ventricle (Correct answer)
- Left ventricle
- Right atrium
Correct answer: Right ventricle
The moderator band (septomarginal trabecula) crosses the right ventricular cavity and carries part of the right bundle branch.
Question 5: Which great vessel carries oxygenated blood from the lungs to the heart?
- Pulmonary artery
- Superior vena cava
- Pulmonary vein (Correct answer)
- Aorta
Correct answer: Pulmonary vein
Pulmonary veins (four in total) return oxygenated blood from the lungs to the left atrium.
Question 6: The Frank-Starling mechanism states that increased preload results in:
- Decreased stroke volume
- Increased stroke volume (Correct answer)
- Decreased heart rate
- Increased afterload
Correct answer: Increased stroke volume
Greater ventricular filling stretches myocardial fibers, increasing the force of contraction and thus stroke volume.
Question 7: Which aortic root structure is identified by echocardiography as the landmark between the aortic annulus and the sinotubular junction?
- Sinuses of Valsalva (Correct answer)
- Aortic isthmus
- Ductus arteriosus remnant
- Coronary ostia ridge
Correct answer: Sinuses of Valsalva
The sinuses of Valsalva are the three dilated pockets of the aortic root located between the annulus and the sinotubular junction, giving rise to the coronary arteries.
CET Cardiovascular Anatomy & Physiology 3
Which of the following best describes preload in cardiac physiology?