EDITION| VERIFIED QUESTIONS CHAPTERS 1-
10 & DETAILED ANSWERS | AEHLERT |
COMPLETE EXAM RESOURCE
📋 ECG COMPLETE TEST BANK
Chapters 1–10 |
CHAPTER 1: ANATOMY & PHYSIOLOGY OF THE HEART
Question 1 Which layer of the heart wall is responsible for the pumping action?
A. Epicardium B. Endocardium C. Myocardium D. Pericardium E. Fibrous skeleton
RATIONALE: The myocardium is the thick muscular middle layer of the heart wall
composed of cardiac muscle cells. It generates the contractile force needed to pump
blood through both pulmonary and systemic circulations.
Question 2 The mitral valve separates which two chambers?
A. Right atrium and right ventricle B. Left ventricle and aorta C. Right ventricle and
pulmonary artery D. Left atrium and left ventricle E. Right atrium and left atrium
RATIONALE: The mitral (bicuspid) valve is located between the left atrium and
left ventricle. It prevents backflow during ventricular systole and has two leaflets, unlike
the tricuspid valve which has three.
Question 3 Which coronary artery is nicknamed the "widow maker"?
A. Right coronary artery B. Circumflex artery C. Posterior descending artery D. Marginal
artery E. Left anterior descending artery (LAD)
, RATIONALE: The LAD supplies the anterior wall of the left ventricle, apex, and
interventricular septum. Occlusion causes a massive anterior MI with high mortality,
earning the nickname "widow maker."
Question 4 How many valves does the heart contain?
A. Two B. Three C. Four D. Five E. Six
RATIONALE: The heart has four valves: the tricuspid, mitral/bicuspid,
pulmonary semilunar, and aortic semilunar valves. They ensure unidirectional blood
flow through the cardiac chambers.
Question 5 The right ventricle pumps blood into which vessel?
A. Aorta B. Superior vena cava C. Pulmonary veins D. Pulmonary artery E. Inferior
vena cava
RATIONALE: The right ventricle ejects deoxygenated blood through the
pulmonary valve into the pulmonary artery, which carries it to the lungs for
oxygenation — the beginning of pulmonary circulation.
Question 6 Which chamber of the heart has the thickest walls?
A. Right atrium B. Left atrium C. Right ventricle D. Left ventricle E. Both ventricles
equally
RATIONALE: The left ventricle has the thickest walls (approximately 8–12 mm)
because it must generate enough pressure to pump oxygenated blood through the
entire systemic circulation against high aortic pressure.
Question 7 The pericardium serves which primary function?
A. Conducts electrical impulses B. Contracts to pump blood C. Provides oxygen to the
myocardium D. Protects and anchors the heart while reducing friction E. Regulates
heart rate
, RATIONALE: The pericardium is a double-walled fibroserous sac surrounding the
heart. It protects the heart from infection, anchors it to surrounding structures, and
contains pericardial fluid that reduces friction during cardiac contractions.
Question 8 Oxygenated blood from the lungs returns to the heart via the:
A. Pulmonary artery B. Superior vena cava C. Inferior vena cava D. Pulmonary
veins E. Coronary sinus
RATIONALE: Pulmonary veins (four total — two from each lung) carry
oxygenated blood from the lungs back to the left atrium, making them unique among
veins which normally carry deoxygenated blood.
Question 9 The tricuspid valve is located between which chambers?
A. Right atrium and right ventricle B. Left atrium and left ventricle C. Right ventricle
and pulmonary artery D. Left ventricle and aorta E. Right and left atria
RATIONALE: The tricuspid valve (three leaflets) is the right atrioventricular
(AV) valve, separating the right atrium from the right ventricle. It prevents backflow
during right ventricular contraction.
Question 10 Cardiac output is calculated as:
A. Stroke volume ÷ heart rate B. Heart rate ÷ stroke volume C. Blood pressure × heart
rate D. Heart rate × stroke volume E. Preload × afterload
RATIONALE: Cardiac output (CO) = Heart rate (HR) × Stroke volume (SV).
Normal CO is approximately 4–8 L/min at rest, representing the total volume of blood
the heart pumps per minute.
Question 11 Which structure divides the right and left sides of the heart?
A. Chordae tendineae B. Papillary muscles C. Pericardium D. Interventricular
septum E. Atrioventricular valve
, RATIONALE: The interventricular septum is a muscular wall separating the right
and left ventricles, preventing mixing of oxygenated and deoxygenated blood. Defects in
this wall (VSD) are the most common congenital heart defect.
Question 12 The coronary arteries receive blood flow primarily during:
A. Ventricular systole B. Ventricular diastole C. Atrial systole D. Isovolumetric
contraction E. Rapid ejection phase
RATIONALE: The coronary arteries are perfused predominantly during diastole
because during systole, myocardial contraction compresses coronary vessels, limiting
flow. Tachycardia shortens diastole and can reduce coronary perfusion.
Question 13 Which term describes the volume of blood ejected by the left ventricle with
each beat?
A. Cardiac output B. Cardiac index C. Preload D. Stroke volume E. Afterload
RATIONALE: Stroke volume (SV) is the volume of blood ejected by the left
ventricle per contraction, normally 60–100 mL. It is influenced by preload, afterload,
and contractility according to Starling's law.
Question 14 The endocardium lines which part of the heart?
A. Outer surface of the heart B. Pericardial sac C. Coronary vessels only D. Inner
chambers and valves of the heart E. Epicardial fat only
RATIONALE: The endocardium is the innermost layer of the heart, lining the
inner chambers, valves, and chordae tendineae. It provides a smooth surface to
reduce friction and prevent clot formation within the heart chambers.
Question 15 What is the primary function of the chordae tendineae?
A. Generate the primary electrical impulse B. Carry oxygenated blood to the
myocardium C. Prevent AV valve leaflets from inverting into the atria D. Control the
semilunar valves E. Conduct impulses from the AV node to ventricles