CET Cardiac Anatomy & 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 composed of cardiac muscle cells that generate the force of contraction.
Question 2: The mitral valve separates which two cardiac chambers?
- Right atrium and right ventricle
- Left ventricle and aorta
- Left atrium and left ventricle (Correct answer)
- Right ventricle and pulmonary artery
Correct answer: Left atrium and left ventricle
The mitral (bicuspid) valve is the atrioventricular valve located between the left atrium and left ventricle.
Question 3: What is the primary pacemaker of the heart under normal conditions?
- AV node
- Bundle of His
- Purkinje fibers
- SA node (Correct answer)
Correct answer: SA node
The sinoatrial (SA) node in the right atrium initiates the electrical impulse at a rate of 60–100 bpm under normal conditions.
Question 4: Which coronary artery primarily supplies the left ventricle's lateral wall?
- Right coronary artery
- Left circumflex artery (Correct answer)
- Left anterior descending artery
- Posterior descending artery
Correct answer: Left circumflex artery
The left circumflex artery branches from the left main coronary artery and supplies the lateral wall of the left ventricle.
Question 5: The QRS complex on an ECG corresponds to which cardiac event?
- Atrial depolarization
- Ventricular repolarization
- Ventricular depolarization (Correct answer)
- Atrial repolarization
Correct answer: Ventricular depolarization
The QRS complex represents the electrical depolarization of the ventricular myocardium, triggering ventricular contraction.
Question 6: Which structure prevents backflow of blood from the aorta into the left ventricle?
- Mitral valve
- Tricuspid valve
- Pulmonic valve
- Aortic valve (Correct answer)
Correct answer: Aortic valve
The aortic semilunar valve closes during ventricular relaxation to prevent blood from returning from the aorta to the left ventricle.
Question 7: What term describes the period during which the ventricles are filling with blood?
- Systole
- Diastole (Correct answer)
- Isovolumetric contraction
- Ejection phase
Correct answer: Diastole
Diastole is the relaxation phase of the cardiac cycle when the ventricles fill with blood from the atria.
CET Cardiac Anatomy & Physiology 2
Which layer of the heart wall contains the cardiac muscle cells responsible for contraction?