NUR 212 Exam 1 | Complete Practice Questions, Verified
Answers & Detailed Rationales (2026/2027)
Question 1
What anatomical structures are responsible for the production of the
first heart sound (𝑆1 )?
• A. Closure of the aortic and pulmonic valves
• B. Closure of the mitral and tricuspid (atrioventricular) valves
• C. Opening of the mitral and tricuspid valves
• D. Turbulent blood flow across the aortic valve during systole
Correct Answer: B. Closure of the mitral and tricuspid (atrioventricular)
valves
Detailed Rationale: The first heart sound (𝑆1 ) marks the beginning of
systole and is caused by the closure of the mitral and tricuspid valves as
ventricular pressure exceeds atrial pressure.
Question 2
What physiological event creates the second heart sound (𝑆2 )?
• A. Rapid ventricular filling during early diastole
• B. Atrial contraction forcing blood into stiff ventricles
• C. Closure of the aortic and pulmonic (semilunar) valves
• D. Opening of the atrioventricular valves
,Correct Answer: C. Closure of the aortic and pulmonic (semilunar)
valves
Detailed Rationale: The second heart sound (𝑆2 ) signifies the end of
ventricular systole and the onset of diastole, produced by the snapping
closure of the aortic and pulmonic valves.
Question 3
What is the clinical significance of hearing a third heart sound (𝑆3 ) in an
adult patient over the age of 40?
• A. It is a completely normal variant indicating superior athletic
conditioning.
• B. It indicates rapid ventricular filling, often associated with left
ventricular dysfunction and volume overload (heart failure).
• C. It signifies severe aortic stenosis and calcification.
• D. It indicates acute coronary artery vasospasm.
Correct Answer: B. It indicates rapid ventricular filling, often associated
with left ventricular dysfunction and volume overload (heart failure).
Detailed Rationale: An 𝑆3 sound occurs early in diastole during rapid
passive filling. In adults over 40, it is frequently pathological, reflecting
decreased ventricular compliance and elevated filling pressures
(ventricular gallop).
Question 4
What does the presence of a fourth heart sound (𝑆4 ) typically indicate?
• A. Atrial contraction against a stiff, non-compliant ventricle (e.g.,
due to hypertrophy or hypertension)
, • B. Rapid closure of the pulmonic valve during inspiration
• C. Normal high cardiac output state in pregnancy
• D. Acute mitral valve prolapse
Correct Answer: A. Atrial contraction against a stiff, non-compliant
ventricle (e.g., due to hypertrophy or hypertension)
Detailed Rationale: An 𝑆4 sound (atrial gallop) occurs late in diastole
when the atria contract to push blood into a non-compliant,
hypertrophied ventricle, commonly seen in chronic hypertension, aortic
stenosis, and coronary artery disease.
Question 5
During which phase of the cardiac cycle does the majority of coronary
blood flow occur?
• A. Ventricular systole
• B. Atrial systole
• C. Ventricular diastole
• D. Isovolumetric contraction
Correct Answer: C. Ventricular diastole
Detailed Rationale: During ventricular systole, contracting myocardial
muscle compresses the intramyocardial blood vessels, severely limiting
flow. Coronary perfusion occurs primarily during diastole when the
aortic valve is closed and myocardial relaxation allows blood to flow into
coronary beds.
Question 6
, What cardiac structures are perfused primarily by the Left Main
Coronary Artery and its branches?
• A. Right atrium and right ventricle
• B. Sinoatrial (SA) node in the majority of individuals and the
posterior wall of the heart
• C. Left atrium, anterior and lateral walls of the left ventricle, and
the interventricular septum
• D. Inferior wall of the right ventricle
Correct Answer: C. Left atrium, anterior and lateral walls of the left
ventricle, and the interventricular septum
Detailed Rationale: The left main coronary artery divides into the Left
Anterior Descending (LAD) and Circumflex arteries, supplying
oxygenated blood to the left atrium, major portions of the left ventricle,
and the bundle of His/septum.
Question 7
What areas of the heart are typically supplied by the Right Coronary
Artery (RCA) in a right-dominant circulation?
• A. Right atrium, right ventricle, SA node, AV node, and inferior wall
of the left ventricle
• B. Lateral wall of the left ventricle exclusively
• C. Apex of the heart and anterior interventricular septum
• D. Left atrial appendage and pulmonary veins
Correct Answer: A. Right atrium, right ventricle, SA node, AV node, and
inferior wall of the left ventricle
Answers & Detailed Rationales (2026/2027)
Question 1
What anatomical structures are responsible for the production of the
first heart sound (𝑆1 )?
• A. Closure of the aortic and pulmonic valves
• B. Closure of the mitral and tricuspid (atrioventricular) valves
• C. Opening of the mitral and tricuspid valves
• D. Turbulent blood flow across the aortic valve during systole
Correct Answer: B. Closure of the mitral and tricuspid (atrioventricular)
valves
Detailed Rationale: The first heart sound (𝑆1 ) marks the beginning of
systole and is caused by the closure of the mitral and tricuspid valves as
ventricular pressure exceeds atrial pressure.
Question 2
What physiological event creates the second heart sound (𝑆2 )?
• A. Rapid ventricular filling during early diastole
• B. Atrial contraction forcing blood into stiff ventricles
• C. Closure of the aortic and pulmonic (semilunar) valves
• D. Opening of the atrioventricular valves
,Correct Answer: C. Closure of the aortic and pulmonic (semilunar)
valves
Detailed Rationale: The second heart sound (𝑆2 ) signifies the end of
ventricular systole and the onset of diastole, produced by the snapping
closure of the aortic and pulmonic valves.
Question 3
What is the clinical significance of hearing a third heart sound (𝑆3 ) in an
adult patient over the age of 40?
• A. It is a completely normal variant indicating superior athletic
conditioning.
• B. It indicates rapid ventricular filling, often associated with left
ventricular dysfunction and volume overload (heart failure).
• C. It signifies severe aortic stenosis and calcification.
• D. It indicates acute coronary artery vasospasm.
Correct Answer: B. It indicates rapid ventricular filling, often associated
with left ventricular dysfunction and volume overload (heart failure).
Detailed Rationale: An 𝑆3 sound occurs early in diastole during rapid
passive filling. In adults over 40, it is frequently pathological, reflecting
decreased ventricular compliance and elevated filling pressures
(ventricular gallop).
Question 4
What does the presence of a fourth heart sound (𝑆4 ) typically indicate?
• A. Atrial contraction against a stiff, non-compliant ventricle (e.g.,
due to hypertrophy or hypertension)
, • B. Rapid closure of the pulmonic valve during inspiration
• C. Normal high cardiac output state in pregnancy
• D. Acute mitral valve prolapse
Correct Answer: A. Atrial contraction against a stiff, non-compliant
ventricle (e.g., due to hypertrophy or hypertension)
Detailed Rationale: An 𝑆4 sound (atrial gallop) occurs late in diastole
when the atria contract to push blood into a non-compliant,
hypertrophied ventricle, commonly seen in chronic hypertension, aortic
stenosis, and coronary artery disease.
Question 5
During which phase of the cardiac cycle does the majority of coronary
blood flow occur?
• A. Ventricular systole
• B. Atrial systole
• C. Ventricular diastole
• D. Isovolumetric contraction
Correct Answer: C. Ventricular diastole
Detailed Rationale: During ventricular systole, contracting myocardial
muscle compresses the intramyocardial blood vessels, severely limiting
flow. Coronary perfusion occurs primarily during diastole when the
aortic valve is closed and myocardial relaxation allows blood to flow into
coronary beds.
Question 6
, What cardiac structures are perfused primarily by the Left Main
Coronary Artery and its branches?
• A. Right atrium and right ventricle
• B. Sinoatrial (SA) node in the majority of individuals and the
posterior wall of the heart
• C. Left atrium, anterior and lateral walls of the left ventricle, and
the interventricular septum
• D. Inferior wall of the right ventricle
Correct Answer: C. Left atrium, anterior and lateral walls of the left
ventricle, and the interventricular septum
Detailed Rationale: The left main coronary artery divides into the Left
Anterior Descending (LAD) and Circumflex arteries, supplying
oxygenated blood to the left atrium, major portions of the left ventricle,
and the bundle of His/septum.
Question 7
What areas of the heart are typically supplied by the Right Coronary
Artery (RCA) in a right-dominant circulation?
• A. Right atrium, right ventricle, SA node, AV node, and inferior wall
of the left ventricle
• B. Lateral wall of the left ventricle exclusively
• C. Apex of the heart and anterior interventricular septum
• D. Left atrial appendage and pulmonary veins
Correct Answer: A. Right atrium, right ventricle, SA node, AV node, and
inferior wall of the left ventricle
