CCS CCS Cardiac Anatomy and Physiology 1 — Questions and Answers
Question 1: Which coronary artery supplies the sinoatrial (SA) node in approximately 60% of individuals?
- Left anterior descending artery
- Right coronary artery (Correct answer)
- Left circumflex artery
- Posterior descending artery
Correct answer: Right coronary artery
The right coronary artery supplies the SA node in about 60% of people, making it critical in bradyarrhythmia management after RCA injury.
Question 2: The left main coronary artery typically bifurcates into which two vessels?
- RCA and LCx
- LAD and RCA
- LAD and LCx (Correct answer)
- LAD and PDA
Correct answer: LAD and LCx
The left main coronary artery divides into the left anterior descending (LAD) and left circumflex (LCx) arteries.
Question 3: Which valve separates the left atrium from the left ventricle?
- Tricuspid valve
- Pulmonary valve
- Aortic valve
- Mitral valve (Correct answer)
Correct answer: Mitral valve
The mitral (bicuspid) valve, composed of anterior and posterior leaflets, separates the left atrium from the left ventricle.
Question 4: Cardiac output is defined as which of the following?
- Stroke volume divided by heart rate
- Heart rate multiplied by stroke volume (Correct answer)
- Mean arterial pressure divided by systemic vascular resistance
- Preload minus afterload
Correct answer: Heart rate multiplied by stroke volume
Cardiac output equals heart rate multiplied by stroke volume, and a normal resting value is approximately 4–8 L/min.
Question 5: The papillary muscles of the left ventricle are connected to the mitral valve leaflets via which structures?
- Tendinous cords (chordae tendineae) (Correct answer)
- Annular sutures
- Pericardial tethers
- Trabeculae carneae
Correct answer: Tendinous cords (chordae tendineae)
Chordae tendineae attach the papillary muscles to the mitral valve leaflets, preventing leaflet prolapse during systole.
Question 6: Which layer of the heart wall is responsible for the contractile function of the myocardium?
- Pericardium
- Epicardium
- Myocardium (Correct answer)
- Endocardium
Correct answer: Myocardium
The myocardium is the thick muscular middle layer composed of cardiac muscle cells that generate the contractile force.
CCS CCS Cardiac Anatomy and Physiology 1
Which coronary artery supplies the sinoatrial (SA) node in approximately 60% of individuals?