CVN MidTerm Exam | Comprehensive Cardiac-Vascular
Nursing Practice Questions & Detailed Rationales 2026/2027
Question 1
Which heart valve separates the left atrium from the left ventricle?
• A. Tricuspid valve
• B. Mitral (bicuspid) valve
• C. Aortic valve
• D. Pulmonic valve
Correct Answer: B. Mitral (bicuspid) valve
Detailed Rationale: The mitral valve (also known as the bicuspid valve)
is located between the left atrium and the left ventricle, preventing
backflow of blood into the atrium during left ventricular systole.
Question 2
What is the primary function of the coronary sinus?
• A. To deliver oxygenated blood to the left ventricular apex
• B. To collect deoxygenated venous blood from the myocardium
and drain it directly into the right atrium
• C. To regulate aortic blood pressure via baroreceptor reflex
• D. To anchor the chordae tendineae of the tricuspid valve
Correct Answer: B. To collect deoxygenated venous blood from the
myocardium and drain it directly into the right atrium
,Detailed Rationale: The coronary sinus is a large venous channel
positioned in the posterior part of the coronary sulcus that collects
most of the venous blood from the heart muscle and empties into the
right atrium.
Question 3
During which phase of the cardiac action potential in ventricular
myocytes does the plateau phase (Phase 2) occur, primarily driven by an
inward calcium current?
• A. Phase 0
• B. Phase 1
• C. Phase 2
• D. Phase 3
Correct Answer: C. Phase 2
Detailed Rationale: Phase 2 is the plateau phase of the cardiac action
potential, characterized by a slow, sustained influx of calcium ions
through L-type calcium channels balanced by potassium efflux,
maintaining depolarization and triggering contraction.
Question 4
What is the normal intrinsic firing rate of the sinoatrial (SA) node in a
healthy resting adult?
• A. 20 to 40 beats per minute
• B. 40 to 60 beats per minute
• C. 60 to 100 beats per minute
, • D. 120 to 150 beats per minute
Correct Answer: C. 60 to 100 beats per minute
Detailed Rationale: The SA node serves as the primary natural
pacemaker of the heart, spontaneously depolarizing at a normal
intrinsic rate of 60 to 100 beats per minute.
Question 5
Which nervous system division mediates an increase in heart rate
(positive chronotropy) and contractility (positive inotropy)?
• A. Parasympathetic nervous system via the vagus nerve
• B. Sympathetic nervous system via beta-1 adrenergic receptors
• C. Somatic nervous system via motor end-plates
• D. Enteric nervous system
Correct Answer: B. Sympathetic nervous system via beta-1 adrenergic
receptors
Detailed Rationale: Activation of the sympathetic nervous system
releases norepinephrine and epinephrine, which bind to beta-1
adrenergic receptors on the heart to increase heart rate, speed
conduction, and enhance contractility.
Question 6
What does the term "preload" specifically describe in cardiovascular
hemodynamics?
• A. The resistance the ventricle encounters during ejection
, • B. The degree of myocardial fiber stretch at the end of diastole,
determined by ventricular filling volume
• C. The velocity of blood flow through the capillary bed
• D. The baseline heart rate at rest
Correct Answer: B. The degree of myocardial fiber stretch at the end of
diastole, determined by ventricular filling volume
Detailed Rationale: Preload represents the volume of blood in the
ventricles at the end of diastole (end-diastolic volume), which stretches
the myocardial fibers prior to contraction in accordance with the Frank-
Starling law.
Question 7
Which physiological factor is the primary determinant of myocardial
oxygen demand?
• A. Serum sodium concentration
• B. Heart rate, myocardial contractility, and wall tension (preload
and afterload)
• C. Hemoglobin oxygen saturation alone
• D. Total circulating blood volume
Correct Answer: B. Heart rate, myocardial contractility, and wall tension
(preload and afterload)
Detailed Rationale: Myocardial oxygen consumption is principally
determined by heart rate, contractility, and wall stress (afterload and
preload). Increases in any of these parameters raise the heart's demand
for oxygen.
Nursing Practice Questions & Detailed Rationales 2026/2027
Question 1
Which heart valve separates the left atrium from the left ventricle?
• A. Tricuspid valve
• B. Mitral (bicuspid) valve
• C. Aortic valve
• D. Pulmonic valve
Correct Answer: B. Mitral (bicuspid) valve
Detailed Rationale: The mitral valve (also known as the bicuspid valve)
is located between the left atrium and the left ventricle, preventing
backflow of blood into the atrium during left ventricular systole.
Question 2
What is the primary function of the coronary sinus?
• A. To deliver oxygenated blood to the left ventricular apex
• B. To collect deoxygenated venous blood from the myocardium
and drain it directly into the right atrium
• C. To regulate aortic blood pressure via baroreceptor reflex
• D. To anchor the chordae tendineae of the tricuspid valve
Correct Answer: B. To collect deoxygenated venous blood from the
myocardium and drain it directly into the right atrium
,Detailed Rationale: The coronary sinus is a large venous channel
positioned in the posterior part of the coronary sulcus that collects
most of the venous blood from the heart muscle and empties into the
right atrium.
Question 3
During which phase of the cardiac action potential in ventricular
myocytes does the plateau phase (Phase 2) occur, primarily driven by an
inward calcium current?
• A. Phase 0
• B. Phase 1
• C. Phase 2
• D. Phase 3
Correct Answer: C. Phase 2
Detailed Rationale: Phase 2 is the plateau phase of the cardiac action
potential, characterized by a slow, sustained influx of calcium ions
through L-type calcium channels balanced by potassium efflux,
maintaining depolarization and triggering contraction.
Question 4
What is the normal intrinsic firing rate of the sinoatrial (SA) node in a
healthy resting adult?
• A. 20 to 40 beats per minute
• B. 40 to 60 beats per minute
• C. 60 to 100 beats per minute
, • D. 120 to 150 beats per minute
Correct Answer: C. 60 to 100 beats per minute
Detailed Rationale: The SA node serves as the primary natural
pacemaker of the heart, spontaneously depolarizing at a normal
intrinsic rate of 60 to 100 beats per minute.
Question 5
Which nervous system division mediates an increase in heart rate
(positive chronotropy) and contractility (positive inotropy)?
• A. Parasympathetic nervous system via the vagus nerve
• B. Sympathetic nervous system via beta-1 adrenergic receptors
• C. Somatic nervous system via motor end-plates
• D. Enteric nervous system
Correct Answer: B. Sympathetic nervous system via beta-1 adrenergic
receptors
Detailed Rationale: Activation of the sympathetic nervous system
releases norepinephrine and epinephrine, which bind to beta-1
adrenergic receptors on the heart to increase heart rate, speed
conduction, and enhance contractility.
Question 6
What does the term "preload" specifically describe in cardiovascular
hemodynamics?
• A. The resistance the ventricle encounters during ejection
, • B. The degree of myocardial fiber stretch at the end of diastole,
determined by ventricular filling volume
• C. The velocity of blood flow through the capillary bed
• D. The baseline heart rate at rest
Correct Answer: B. The degree of myocardial fiber stretch at the end of
diastole, determined by ventricular filling volume
Detailed Rationale: Preload represents the volume of blood in the
ventricles at the end of diastole (end-diastolic volume), which stretches
the myocardial fibers prior to contraction in accordance with the Frank-
Starling law.
Question 7
Which physiological factor is the primary determinant of myocardial
oxygen demand?
• A. Serum sodium concentration
• B. Heart rate, myocardial contractility, and wall tension (preload
and afterload)
• C. Hemoglobin oxygen saturation alone
• D. Total circulating blood volume
Correct Answer: B. Heart rate, myocardial contractility, and wall tension
(preload and afterload)
Detailed Rationale: Myocardial oxygen consumption is principally
determined by heart rate, contractility, and wall stress (afterload and
preload). Increases in any of these parameters raise the heart's demand
for oxygen.
