BIOS252 / BIOS 252 Exam 3 Anatomy and
Physiology II ACTUAL EXAM 2026/2027 |
BIOS 252 A&P II Exam 3 | Verified Q&A |
Pass Guaranteed - A+ Graded
Section 1: Cardiovascular System – Heart & Circulation (Q1–Q12)
Q1: If a patient has a heart rate of 120 bpm and stroke volume of 70 mL, what is the cardiac output?
A. 5.6 L/min
B. 7.0 L/min
C. 8.4 L/min [CORRECT]
D. 9.2 L/min
Correct Answer: C
Rationale: Cardiac output is calculated as heart rate multiplied by stroke volume (CO = HR × SV). With a
heart rate of 120 beats per minute and stroke volume of 70 mL per beat, the cardiac output equals 120
× 70 = 8,400 mL/min, or 8.4 L/min. This represents the total volume of blood pumped by each ventricle
per minute under the given conditions. During exercise or stress, increased heart rate and enhanced
stroke volume (through increased contractility and venous return) can raise cardiac output to 20–25
L/min in trained athletes.
Q2: The first heart sound (S1, "lub") is produced by the closure of which valves?
A. The aortic and pulmonary valves
B. The tricuspid and mitral (bicuspid) valves [CORRECT]
C. The pulmonary and tricuspid valves
D. The aortic and mitral valves
Correct Answer: B
Rationale: The first heart sound (S1) marks the beginning of systole and is produced by the closure of
the atrioventricular (AV) valves—the tricuspid valve (right side) and the mitral/bicuspid valve (left side).
,These valves close when ventricular pressure exceeds atrial pressure, preventing backflow into the atria
during ventricular contraction. The second heart sound (S2, "dub") is produced by closure of the
semilunar valves (aortic and pulmonary) at the end of systole when ventricular pressure falls below
aortic and pulmonary artery pressures.
Q3: Blood flows through the heart in which correct sequence? (Order the following: 1–5)
A. 1. Right atrium → 2. Right ventricle → 3. Pulmonary trunk → 4. Left atrium → 5. Left ventricle
[CORRECT]
B. 1. Left atrium → 2. Left ventricle → 3. Aorta → 4. Right atrium → 5. Right ventricle
C. 1. Right ventricle → 2. Left atrium → 3. Left ventricle → 4. Right atrium → 5. Pulmonary trunk
D. 1. Left ventricle → 2. Aorta → 3. Right atrium → 4. Right ventricle → 5. Pulmonary trunk
Correct Answer: A
Rationale: The systemic and pulmonary circulations are connected in series through the heart.
Deoxygenated blood returns from systemic circulation via the venae cavae into the right atrium (1),
passes through the tricuspid valve into the right ventricle (2), and is pumped through the pulmonary
valve into the pulmonary trunk (3) to the lungs for oxygenation. Oxygenated blood returns via
pulmonary veins to the left atrium (4), passes through the mitral valve into the left ventricle (5), and is
ejected through the aortic valve into systemic circulation. This unidirectional flow is maintained by
pressure gradients and competent valves.
Q4: During the cardiac cycle, ventricular filling occurs primarily during which phase?
A. Isovolumetric contraction
B. Ventricular ejection
C. Ventricular diastole [CORRECT]
D. Isovolumetric relaxation
Correct Answer: C
Rationale: Ventricular filling occurs during ventricular diastole, the period of ventricular relaxation when
myocardial fibers lengthen and chamber pressure drops below atrial pressure. The majority of
ventricular filling (approximately 70–80%) occurs passively during early diastole (rapid filling phase) as
blood flows down the pressure gradient from atria to ventricles. The remaining 20–30% of filling occurs
during atrial systole (the "atrial kick") at the end of diastole, just before ventricular contraction begins.
This passive filling mechanism explains why patients can tolerate atrial fibrillation (loss of atrial kick)
with only modest reduction in cardiac output.
, Q5: The sinoatrial (SA) node is located in which anatomical region of the heart?
A. The interventricular septum near the apex
B. The posterior wall of the left atrium
C. The right atrial wall near the opening of the superior vena cava [CORRECT]
D. The base of the aorta
Correct Answer: C
Rationale: The sinoatrial (SA) node is the primary pacemaker of the heart, located in the posterior wall
of the right atrium near the junction with the superior vena cava. It consists of specialized cardiac
muscle cells with unstable resting membrane potentials that spontaneously depolarize, generating
action potentials at a rate of 60–100 beats per minute under normal conditions. The SA node initiates
the electrical impulse that spreads through atrial myocardium (producing the P wave on ECG) and
reaches the atrioventricular (AV) node, which delays conduction to allow complete atrial emptying
before ventricular contraction.
Q6: On a standard ECG, the QRS complex represents which electrical event?
A. Atrial depolarization
B. Atrial repolarization
C. Ventricular depolarization [CORRECT]
D. Ventricular repolarization
Correct Answer: C
Rationale: The QRS complex on the electrocardiogram represents ventricular depolarization—the rapid,
coordinated spread of the action potential through the ventricular myocardium via the His-Purkinje
system. Because ventricular muscle mass is much greater than atrial mass, the QRS complex has a larger
amplitude than the P wave. The Q wave represents initial septal depolarization; the R wave represents
dominant ventricular depolarization; and the S wave represents terminal depolarization of the basal
ventricles. Ventricular repolarization is represented by the T wave; atrial repolarization is usually hidden
within the QRS complex due to its smaller amplitude and simultaneous occurrence.
Q7: The coronary arteries receive blood during which phase of the cardiac cycle?
A. Ventricular systole
B. Ventricular diastole [CORRECT]
C. Atrial systole only
D. Throughout the entire cardiac cycle equally
Correct Answer: B
Physiology II ACTUAL EXAM 2026/2027 |
BIOS 252 A&P II Exam 3 | Verified Q&A |
Pass Guaranteed - A+ Graded
Section 1: Cardiovascular System – Heart & Circulation (Q1–Q12)
Q1: If a patient has a heart rate of 120 bpm and stroke volume of 70 mL, what is the cardiac output?
A. 5.6 L/min
B. 7.0 L/min
C. 8.4 L/min [CORRECT]
D. 9.2 L/min
Correct Answer: C
Rationale: Cardiac output is calculated as heart rate multiplied by stroke volume (CO = HR × SV). With a
heart rate of 120 beats per minute and stroke volume of 70 mL per beat, the cardiac output equals 120
× 70 = 8,400 mL/min, or 8.4 L/min. This represents the total volume of blood pumped by each ventricle
per minute under the given conditions. During exercise or stress, increased heart rate and enhanced
stroke volume (through increased contractility and venous return) can raise cardiac output to 20–25
L/min in trained athletes.
Q2: The first heart sound (S1, "lub") is produced by the closure of which valves?
A. The aortic and pulmonary valves
B. The tricuspid and mitral (bicuspid) valves [CORRECT]
C. The pulmonary and tricuspid valves
D. The aortic and mitral valves
Correct Answer: B
Rationale: The first heart sound (S1) marks the beginning of systole and is produced by the closure of
the atrioventricular (AV) valves—the tricuspid valve (right side) and the mitral/bicuspid valve (left side).
,These valves close when ventricular pressure exceeds atrial pressure, preventing backflow into the atria
during ventricular contraction. The second heart sound (S2, "dub") is produced by closure of the
semilunar valves (aortic and pulmonary) at the end of systole when ventricular pressure falls below
aortic and pulmonary artery pressures.
Q3: Blood flows through the heart in which correct sequence? (Order the following: 1–5)
A. 1. Right atrium → 2. Right ventricle → 3. Pulmonary trunk → 4. Left atrium → 5. Left ventricle
[CORRECT]
B. 1. Left atrium → 2. Left ventricle → 3. Aorta → 4. Right atrium → 5. Right ventricle
C. 1. Right ventricle → 2. Left atrium → 3. Left ventricle → 4. Right atrium → 5. Pulmonary trunk
D. 1. Left ventricle → 2. Aorta → 3. Right atrium → 4. Right ventricle → 5. Pulmonary trunk
Correct Answer: A
Rationale: The systemic and pulmonary circulations are connected in series through the heart.
Deoxygenated blood returns from systemic circulation via the venae cavae into the right atrium (1),
passes through the tricuspid valve into the right ventricle (2), and is pumped through the pulmonary
valve into the pulmonary trunk (3) to the lungs for oxygenation. Oxygenated blood returns via
pulmonary veins to the left atrium (4), passes through the mitral valve into the left ventricle (5), and is
ejected through the aortic valve into systemic circulation. This unidirectional flow is maintained by
pressure gradients and competent valves.
Q4: During the cardiac cycle, ventricular filling occurs primarily during which phase?
A. Isovolumetric contraction
B. Ventricular ejection
C. Ventricular diastole [CORRECT]
D. Isovolumetric relaxation
Correct Answer: C
Rationale: Ventricular filling occurs during ventricular diastole, the period of ventricular relaxation when
myocardial fibers lengthen and chamber pressure drops below atrial pressure. The majority of
ventricular filling (approximately 70–80%) occurs passively during early diastole (rapid filling phase) as
blood flows down the pressure gradient from atria to ventricles. The remaining 20–30% of filling occurs
during atrial systole (the "atrial kick") at the end of diastole, just before ventricular contraction begins.
This passive filling mechanism explains why patients can tolerate atrial fibrillation (loss of atrial kick)
with only modest reduction in cardiac output.
, Q5: The sinoatrial (SA) node is located in which anatomical region of the heart?
A. The interventricular septum near the apex
B. The posterior wall of the left atrium
C. The right atrial wall near the opening of the superior vena cava [CORRECT]
D. The base of the aorta
Correct Answer: C
Rationale: The sinoatrial (SA) node is the primary pacemaker of the heart, located in the posterior wall
of the right atrium near the junction with the superior vena cava. It consists of specialized cardiac
muscle cells with unstable resting membrane potentials that spontaneously depolarize, generating
action potentials at a rate of 60–100 beats per minute under normal conditions. The SA node initiates
the electrical impulse that spreads through atrial myocardium (producing the P wave on ECG) and
reaches the atrioventricular (AV) node, which delays conduction to allow complete atrial emptying
before ventricular contraction.
Q6: On a standard ECG, the QRS complex represents which electrical event?
A. Atrial depolarization
B. Atrial repolarization
C. Ventricular depolarization [CORRECT]
D. Ventricular repolarization
Correct Answer: C
Rationale: The QRS complex on the electrocardiogram represents ventricular depolarization—the rapid,
coordinated spread of the action potential through the ventricular myocardium via the His-Purkinje
system. Because ventricular muscle mass is much greater than atrial mass, the QRS complex has a larger
amplitude than the P wave. The Q wave represents initial septal depolarization; the R wave represents
dominant ventricular depolarization; and the S wave represents terminal depolarization of the basal
ventricles. Ventricular repolarization is represented by the T wave; atrial repolarization is usually hidden
within the QRS complex due to its smaller amplitude and simultaneous occurrence.
Q7: The coronary arteries receive blood during which phase of the cardiac cycle?
A. Ventricular systole
B. Ventricular diastole [CORRECT]
C. Atrial systole only
D. Throughout the entire cardiac cycle equally
Correct Answer: B
