CMT Cardiac Anatomy and Physiology 2 — Questions and Answers
Question 1: Which layer of the heart wall contains the cardiac muscle cells responsible for contraction?
- Epicardium
- Myocardium (Correct answer)
- Endocardium
- Pericardium
Correct answer: Myocardium
The myocardium is the thick middle layer of the heart wall composed of cardiac muscle cells that generate the force of contraction.
Question 2: The mitral valve is located between which two cardiac chambers?
- Right atrium and right ventricle
- Left atrium and left ventricle (Correct answer)
- Left ventricle and aorta
- Right ventricle and pulmonary artery
Correct answer: Left atrium and left ventricle
The mitral (bicuspid) valve is the atrioventricular valve on the left side of the heart, separating the left atrium from the left ventricle.
Question 3: What is the primary function of the chordae tendineae?
- Conduct electrical impulses to the ventricles
- Prevent AV valve leaflets from prolapsing into the atria (Correct answer)
- Connect the sinoatrial node to the AV node
- Regulate blood flow through the semilunar valves
Correct answer: Prevent AV valve leaflets from prolapsing into the atria
Chordae tendineae are fibrous cords that anchor the AV valve leaflets to papillary muscles, preventing them from inverting into the atria during ventricular contraction.
Question 4: Which coronary artery supplies the lateral wall of the left ventricle?
- Right coronary artery
- Left anterior descending artery
- Left circumflex artery (Correct answer)
- Posterior descending artery
Correct answer: Left circumflex artery
The left circumflex artery branches from the left main coronary artery and supplies the lateral and posterior walls of the left ventricle.
Question 5: During diastole, which event occurs in the cardiac cycle?
- Ventricular contraction and blood ejection
- Closure of the semilunar valves
- AV valves close and pressure rises
- Ventricular relaxation and filling with blood (Correct answer)
Correct answer: Ventricular relaxation and filling with blood
Diastole is the phase of cardiac relaxation during which the ventricles refill with blood from the atria through open AV valves.
Question 6: The right coronary artery most commonly supplies which of the following structures?
- Left bundle branch
- Sinoatrial node and AV node (Correct answer)
- Anterior interventricular septum
- Left circumflex territory
Correct answer: Sinoatrial node and AV node
The right coronary artery supplies the SA node in about 60% of people and the AV node in about 85-90% of people, making it critical to cardiac conduction.
Question 7: What does the term 'cardiac output' refer to?
- The electrical voltage generated by the heart
- The volume of blood ejected per beat
- The total volume of blood pumped per minute (Correct answer)
- The pressure generated in the aorta
Correct answer: The total volume of blood pumped per minute
Cardiac output is the total volume of blood the heart pumps per minute, calculated as heart rate multiplied by stroke volume (normal ~5 L/min at rest).
CMT Cardiac Anatomy and Physiology 2
Which layer of the heart wall contains the cardiac muscle cells responsible for contraction?