BIOL 252 Module 4 Exam Prep 2026 | 70+ Practice Questions
with Answers & Explanations | Human Anatomy & Physiology
II Guide
SECTION A: CARDIOVASCULAR SYSTEM – HEART AND CIRCULATION (Questions 1–60)
1. A patient has a heart rate of 50 bpm, blood pressure 90/60 mm Hg, and complains of
lightheadedness. Which component of the cardiac conduction system is most likely dysfunctional?
A. Sinoatrial (SA) node
B. Atrioventricular (AV) node
C. Bundle of His
D. Purkinje fibers
Answer: A
Explanation: The SA node is the normal pacemaker; dysfunction causes bradycardia (sinus bradycardia)
with a junctional or ventricular escape rhythm.
2. Which of the following is the correct order of blood flow through the heart and lungs?
A. Right atrium → tricuspid valve → right ventricle → pulmonary valve → pulmonary artery → lungs →
pulmonary veins → left atrium → mitral valve → left ventricle → aortic valve → aorta
B. Right atrium → mitral valve → right ventricle → aortic valve → aorta → lungs → pulmonary veins →
left atrium → tricuspid valve → left ventricle → pulmonary artery
C. Left atrium → tricuspid valve → left ventricle → pulmonary valve → pulmonary artery → lungs →
pulmonary veins → right atrium → mitral valve → right ventricle → aorta
D. Right atrium → pulmonary valve → right ventricle → tricuspid valve → pulmonary artery → lungs →
pulmonary veins → left atrium → aortic valve → left ventricle → mitral valve → aorta
Answer: A
Explanation: This is the standard pathway of systemic and pulmonary circulation; the right side pumps
deoxygenated blood to the lungs, the left side pumps oxygenated blood to the body.
3. The P wave on an electrocardiogram (ECG) represents:
,A. Atrial depolarization
B. Ventricular depolarization
C. Ventricular repolarization
D. Atrial repolarization
Answer: A
Explanation: The P wave is caused by electrical activity spreading from the SA node across the atria,
triggering atrial contraction.
4. Which heart sound is produced by the closure of the atrioventricular (AV) valves?
A. S1 (“lub”)
B. S2 (“dub”)
C. S3
D. S4
Answer: A
Explanation: S1 is the sound of mitral and tricuspid valves closing at the start of systole; S2 is semilunar
valve closure.
5. A patient has an ejection fraction of 35% (normal >55%). This indicates:
A. Reduced systolic function (heart failure with reduced ejection fraction)
B. Normal cardiac function
C. Diastolic dysfunction
D. Valve stenosis
Answer: A
Explanation: Ejection fraction is the percentage of blood pumped out of the left ventricle with each
beat; <40% indicates systolic heart failure.
6. Which of the following is the primary determinant of cardiac preload?
A. End-diastolic volume (venous return)
B. Systemic vascular resistance
C. Heart rate
,D. Myocardial contractility
Answer: A
Explanation: Preload is the stretch on the ventricular wall before contraction, determined by the volume
of blood in the ventricle at end-diastole (venous return).
7. The Frank-Starling law of the heart states that:
A. Increased end-diastolic volume leads to increased stroke volume
B. Increased afterload leads to increased stroke volume
C. Increased heart rate always increases cardiac output
D. Decreased contractility increases stroke volume
Answer: A
Explanation: The Frank-Starling mechanism ensures that the heart pumps out the volume it receives;
within limits, greater filling increases contraction strength.
8. A patient with a heart murmur that is holosystolic, heard best at the apex, and radiates to the axilla
most likely has:
A. Mitral regurgitation
B. Aortic stenosis
C. Tricuspid regurgitation
D. Mitral stenosis
Answer: A
Explanation: Mitral regurgitation murmur is holosystolic, loudest at the apex, and radiates to the left
axilla.
9. The second heart sound (S2) splits during inspiration because:
A. Increased venous return to the right ventricle delays pulmonic valve closure
B. Decreased venous return to the left ventricle delays aortic valve closure
C. Increased intrathoracic pressure delays both valves
D. The heart rate slows during inspiration
Answer: A
, Explanation: Inspiration increases right ventricular filling, prolonging right ventricular ejection and
delaying pulmonic valve closure, causing physiologic splitting of S2.
10. Which of the following vessels carries deoxygenated blood from the heart to the lungs?
A. Pulmonary artery
B. Pulmonary vein
C. Aorta
D. Superior vena cava
Answer: A
Explanation: The pulmonary artery is the only artery that carries deoxygenated blood; it branches to the
lungs.
11. The cardiac output (CO) is calculated as:
A. Heart rate × Stroke volume
B. Heart rate × Blood pressure
C. Stroke volume / Heart rate
D. End-diastolic volume – End-systolic volume
Answer: A
Explanation: CO = HR × SV; normal adult CO is about 5 L/min.
12. A patient has a blood pressure of 140/90 mm Hg. The mean arterial pressure (MAP) is
approximately:
A. 107 mm Hg (diastolic + 1/3 pulse pressure)
B. 115 mm Hg
C. 100 mm Hg
D. 120 mm Hg
Answer: A
Explanation: MAP = DBP + 1/3(SBP – DBP) = 90 + 1/3(50) = 90 + 16.7 = 106.7 ≈ 107 mm Hg.
13. Which of the following is a characteristic of the cardiac action potential in ventricular myocytes?
with Answers & Explanations | Human Anatomy & Physiology
II Guide
SECTION A: CARDIOVASCULAR SYSTEM – HEART AND CIRCULATION (Questions 1–60)
1. A patient has a heart rate of 50 bpm, blood pressure 90/60 mm Hg, and complains of
lightheadedness. Which component of the cardiac conduction system is most likely dysfunctional?
A. Sinoatrial (SA) node
B. Atrioventricular (AV) node
C. Bundle of His
D. Purkinje fibers
Answer: A
Explanation: The SA node is the normal pacemaker; dysfunction causes bradycardia (sinus bradycardia)
with a junctional or ventricular escape rhythm.
2. Which of the following is the correct order of blood flow through the heart and lungs?
A. Right atrium → tricuspid valve → right ventricle → pulmonary valve → pulmonary artery → lungs →
pulmonary veins → left atrium → mitral valve → left ventricle → aortic valve → aorta
B. Right atrium → mitral valve → right ventricle → aortic valve → aorta → lungs → pulmonary veins →
left atrium → tricuspid valve → left ventricle → pulmonary artery
C. Left atrium → tricuspid valve → left ventricle → pulmonary valve → pulmonary artery → lungs →
pulmonary veins → right atrium → mitral valve → right ventricle → aorta
D. Right atrium → pulmonary valve → right ventricle → tricuspid valve → pulmonary artery → lungs →
pulmonary veins → left atrium → aortic valve → left ventricle → mitral valve → aorta
Answer: A
Explanation: This is the standard pathway of systemic and pulmonary circulation; the right side pumps
deoxygenated blood to the lungs, the left side pumps oxygenated blood to the body.
3. The P wave on an electrocardiogram (ECG) represents:
,A. Atrial depolarization
B. Ventricular depolarization
C. Ventricular repolarization
D. Atrial repolarization
Answer: A
Explanation: The P wave is caused by electrical activity spreading from the SA node across the atria,
triggering atrial contraction.
4. Which heart sound is produced by the closure of the atrioventricular (AV) valves?
A. S1 (“lub”)
B. S2 (“dub”)
C. S3
D. S4
Answer: A
Explanation: S1 is the sound of mitral and tricuspid valves closing at the start of systole; S2 is semilunar
valve closure.
5. A patient has an ejection fraction of 35% (normal >55%). This indicates:
A. Reduced systolic function (heart failure with reduced ejection fraction)
B. Normal cardiac function
C. Diastolic dysfunction
D. Valve stenosis
Answer: A
Explanation: Ejection fraction is the percentage of blood pumped out of the left ventricle with each
beat; <40% indicates systolic heart failure.
6. Which of the following is the primary determinant of cardiac preload?
A. End-diastolic volume (venous return)
B. Systemic vascular resistance
C. Heart rate
,D. Myocardial contractility
Answer: A
Explanation: Preload is the stretch on the ventricular wall before contraction, determined by the volume
of blood in the ventricle at end-diastole (venous return).
7. The Frank-Starling law of the heart states that:
A. Increased end-diastolic volume leads to increased stroke volume
B. Increased afterload leads to increased stroke volume
C. Increased heart rate always increases cardiac output
D. Decreased contractility increases stroke volume
Answer: A
Explanation: The Frank-Starling mechanism ensures that the heart pumps out the volume it receives;
within limits, greater filling increases contraction strength.
8. A patient with a heart murmur that is holosystolic, heard best at the apex, and radiates to the axilla
most likely has:
A. Mitral regurgitation
B. Aortic stenosis
C. Tricuspid regurgitation
D. Mitral stenosis
Answer: A
Explanation: Mitral regurgitation murmur is holosystolic, loudest at the apex, and radiates to the left
axilla.
9. The second heart sound (S2) splits during inspiration because:
A. Increased venous return to the right ventricle delays pulmonic valve closure
B. Decreased venous return to the left ventricle delays aortic valve closure
C. Increased intrathoracic pressure delays both valves
D. The heart rate slows during inspiration
Answer: A
, Explanation: Inspiration increases right ventricular filling, prolonging right ventricular ejection and
delaying pulmonic valve closure, causing physiologic splitting of S2.
10. Which of the following vessels carries deoxygenated blood from the heart to the lungs?
A. Pulmonary artery
B. Pulmonary vein
C. Aorta
D. Superior vena cava
Answer: A
Explanation: The pulmonary artery is the only artery that carries deoxygenated blood; it branches to the
lungs.
11. The cardiac output (CO) is calculated as:
A. Heart rate × Stroke volume
B. Heart rate × Blood pressure
C. Stroke volume / Heart rate
D. End-diastolic volume – End-systolic volume
Answer: A
Explanation: CO = HR × SV; normal adult CO is about 5 L/min.
12. A patient has a blood pressure of 140/90 mm Hg. The mean arterial pressure (MAP) is
approximately:
A. 107 mm Hg (diastolic + 1/3 pulse pressure)
B. 115 mm Hg
C. 100 mm Hg
D. 120 mm Hg
Answer: A
Explanation: MAP = DBP + 1/3(SBP – DBP) = 90 + 1/3(50) = 90 + 16.7 = 106.7 ≈ 107 mm Hg.
13. Which of the following is a characteristic of the cardiac action potential in ventricular myocytes?
