EKG certification Certification EKG Cardiac Anatomy & Physiology 2 — Questions and Answers
Question 1: Which heart valve separates the left atrium from the left ventricle?
- Mitral valve (Correct answer)
- Tricuspid valve
- Aortic valve
- Pulmonic valve
Correct answer: Mitral valve
The mitral (bicuspid) valve is located between the left atrium and left ventricle, preventing backflow during ventricular contraction.
Question 2: What is the normal duration of the PR interval on an EKG?
- 0.12 to 0.20 seconds (Correct answer)
- 0.06 to 0.10 seconds
- 0.20 to 0.40 seconds
- 0.36 to 0.44 seconds
Correct answer: 0.12 to 0.20 seconds
The PR interval normally measures 0.12 to 0.20 seconds and represents the time from atrial depolarization to the onset of ventricular depolarization.
Question 3: The coronary sinus drains deoxygenated blood from the cardiac veins into which chamber?
- Right atrium (Correct answer)
- Left atrium
- Right ventricle
- Left ventricle
Correct answer: Right atrium
The coronary sinus empties deoxygenated blood from the myocardial circulation directly into the right atrium.
Question 4: Which layer of the heart wall is responsible for the contractile force during each heartbeat?
- Myocardium (Correct answer)
- Endocardium
- Epicardium
- Pericardium
Correct answer: Myocardium
The myocardium is the thick muscular middle layer of the heart wall that generates the force needed to pump blood.
Question 5: During which phase of the cardiac cycle do the ventricles fill with blood passively?
- Diastole (Correct answer)
- Systole
- Isovolumetric contraction
- Ejection phase
Correct answer: Diastole
During diastole the ventricles relax and fill passively with blood flowing from the atria through the open AV valves.
Question 6: The right coronary artery primarily supplies blood to which structure critical for the heart's electrical conduction?
- SA node and AV node (Correct answer)
- Bundle of His
- Left bundle branch
- Purkinje fibers
Correct answer: SA node and AV node
In most people the right coronary artery supplies blood to both the SA node and the AV node, making it critical for normal cardiac rhythm.
EKG certification Certification EKG Cardiac Anatomy & Physiology 2
Which heart valve separates the left atrium from the left ventricle?