CCI Cardiac Anatomy and Physiology 2 — Questions and Answers
Question 1: The chordae tendineae attach the leaflets of the AV valves to which cardiac structures?
- Papillary muscles (Correct answer)
- Trabeculae carneae
- Interventricular septum
- Moderator band
Correct answer: Papillary muscles
Chordae tendineae are fibrous cords that connect the AV valve leaflets to the papillary muscles, preventing leaflet prolapse during ventricular systole.
Question 2: Which layer of the heart wall contains the cardiac muscle cells (cardiomyocytes)?
- Pericardium
- Epicardium
- Myocardium (Correct answer)
- Endocardium
Correct answer: Myocardium
The myocardium is the middle and thickest layer of the heart wall composed of cardiac muscle cells responsible for the pumping action.
Question 3: The coronary sinus drains primarily into which cardiac chamber?
- Left atrium
- Right atrium (Correct answer)
- Right ventricle
- Left ventricle
Correct 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.
Question 4: During isovolumetric contraction, which valves are CLOSED?
- Mitral and aortic valves open
- Aortic and pulmonic valves open
- All four valves are closed (Correct answer)
- Mitral and tricuspid valves open
Correct 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.
Question 5: The P-wave on a standard ECG corresponds to which mechanical event?
- Ventricular depolarization
- Atrial repolarization
- Atrial depolarization (Correct answer)
- Ventricular repolarization
Correct answer: Atrial depolarization
The P-wave represents the electrical depolarization of the atria, which precedes and triggers atrial contraction.
Question 6: Which of the following best describes the Frank-Starling mechanism?
- Increased heart rate leads to decreased stroke volume
- Greater ventricular end-diastolic volume produces greater stroke volume (Correct answer)
- Afterload is inversely proportional to ejection fraction
- Heart rate is directly controlled by preload
Correct 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.
Question 7: The right coronary artery most commonly supplies the sinoatrial node in what percentage of the population?
- 30%
- 55% (Correct answer)
- 60%
- 80%
Correct 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.
CCI Cardiac Anatomy and Physiology 2
The chordae tendineae attach the leaflets of the AV valves to which cardiac structures?