BIOS 255 Anatomy and Physiology III Exam 2 Complete
Guide Actual 2024/2025 with Detailed Rationales |
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Section 1: Cardiovascular System – Heart & Vessels (14 Questions)
Q1: The epicardium is anatomically synonymous with which of the following?
A. The endocardium lining the heart chambers
B. The fibrous pericardium surrounding the heart
C. The visceral layer of the serous pericardium [CORRECT]
D. The myocardium containing cardiac muscle
Correct Answer: C
Rationale: Correct because the epicardium is the outermost heart layer and is
identical to the visceral layer of the serous pericardium, which directly covers the
myocardium.
Q2: During which phase of the cardiac cycle do the atrioventricular (AV) valves close
and the semilunar valves remain closed?
A. Atrial systole
B. Ventricular ejection
C. Isovolumetric contraction [CORRECT]
D. Ventricular filling
Correct Answer: C
Rationale: Correct because isovolumetric contraction begins immediately after the
AV valves close; during this brief period, ventricular pressure rises with no change in
volume because all valves are closed.
Q3: Which component of the cardiac conduction system is responsible for the
spontaneous depolarization that initiates each heartbeat?
A. The atrioventricular (AV) node
B. The bundle of His
C. The sinoatrial (SA) node [CORRECT]
D. The Purkinje fibers
Correct Answer: C
,Rationale: Correct because the SA node has the fastest intrinsic firing rate (60–100
beats per minute) and serves as the normal pacemaker of the heart, initiating the
electrical impulse.
Q4: On a standard ECG tracing, the P wave corresponds to which physiological
event?
A. Ventricular depolarization
B. Atrial depolarization [CORRECT]
C. Ventricular repolarization
D. Atrial repolarization
Correct Answer: B
Rationale: Correct because the P wave represents the wave of depolarization
spreading through the atria, triggering atrial contraction.
Q5: If a patient has a heart rate of 75 beats per minute and an end-diastolic volume
of 140 mL with an end-systolic volume of 70 mL, what is the cardiac output?
A. 5.25 L/min [CORRECT]
B. 7.0 L/min
C. 10.5 L/min
D. 15.0 L/min
Correct Answer: A
Rationale: Correct because stroke volume = EDV − ESV = 140 − 70 = 70 mL; cardiac
output = SV × HR = 70 mL × 75 = 5,250 mL/min = 5.25 L/min.
Q6: Which layer of a blood vessel contains the smooth muscle and elastic fibers that
allow vasoconstriction and vasodilation?
A. Tunica intima
B. Tunica media [CORRECT]
C. Tunica externa
D. Tunica adventitia
Correct Answer: B
Rationale: Correct because the tunica media is the middle layer containing circular
smooth muscle and elastic tissue, which regulates vessel diameter and blood flow.
Q7: Arterioles are considered the primary site of which physiological function?
A. Blood reservoir storage
B. Exchange of gases and nutrients
C. Peripheral resistance regulation [CORRECT]
D. One-way blood return to the heart
, Correct Answer: C
Rationale: Correct because arterioles have thick muscular walls relative to their
diameter and are the major resistance vessels that control blood flow into capillary
beds.
Q8: According to the Starling forces, which pressure promotes fluid movement out of
the capillary at the arterial end?
A. Interstitial fluid hydrostatic pressure
B. Blood colloid osmotic pressure
C. Capillary hydrostatic pressure [CORRECT]
D. Interstitial fluid osmotic pressure
Correct Answer: C
Rationale: Correct because capillary hydrostatic pressure (blood pressure) is the
main filtration force that pushes fluid and solutes out of the capillary into the
interstitial space.
Q9: A sudden increase in blood pressure triggers baroreceptors in the carotid
sinuses. Which response occurs to restore homeostasis?
A. Increased sympathetic stimulation of the heart
B. Increased heart rate and contractility
C. Decreased parasympathetic stimulation of the SA node
D. Vasodilation and decreased cardiac output [CORRECT]
Correct Answer: D
Rationale: Correct because elevated baroreceptor firing inhibits sympathetic output
and enhances parasympathetic tone, resulting in vasodilation, bradycardia, and
reduced cardiac output to lower blood pressure.
Q10: (Data Question) A patient has the following hemodynamic measurements:
mean arterial pressure = 93 mmHg, central venous pressure = 2 mmHg, and cardiac
output = 5.0 L/min. What is the total peripheral resistance (TPR)?
A. 12.4 mmHg·min/L
B. 15.6 mmHg·min/L
C. 18.2 mmHg·min/L [CORRECT]
D. 22.8 mmHg·min/L
Correct Answer: C
Rationale: Correct because TPR = (MAP − CVP)/CO = (93 − 2)/5.0 = 91/5.0 = 18.2
mmHg·min/L, reflecting the resistance the heart must overcome to perfuse tissues.
Guide Actual 2024/2025 with Detailed Rationales |
100% Verified | Pass Guaranteed – A+ Graded
Section 1: Cardiovascular System – Heart & Vessels (14 Questions)
Q1: The epicardium is anatomically synonymous with which of the following?
A. The endocardium lining the heart chambers
B. The fibrous pericardium surrounding the heart
C. The visceral layer of the serous pericardium [CORRECT]
D. The myocardium containing cardiac muscle
Correct Answer: C
Rationale: Correct because the epicardium is the outermost heart layer and is
identical to the visceral layer of the serous pericardium, which directly covers the
myocardium.
Q2: During which phase of the cardiac cycle do the atrioventricular (AV) valves close
and the semilunar valves remain closed?
A. Atrial systole
B. Ventricular ejection
C. Isovolumetric contraction [CORRECT]
D. Ventricular filling
Correct Answer: C
Rationale: Correct because isovolumetric contraction begins immediately after the
AV valves close; during this brief period, ventricular pressure rises with no change in
volume because all valves are closed.
Q3: Which component of the cardiac conduction system is responsible for the
spontaneous depolarization that initiates each heartbeat?
A. The atrioventricular (AV) node
B. The bundle of His
C. The sinoatrial (SA) node [CORRECT]
D. The Purkinje fibers
Correct Answer: C
,Rationale: Correct because the SA node has the fastest intrinsic firing rate (60–100
beats per minute) and serves as the normal pacemaker of the heart, initiating the
electrical impulse.
Q4: On a standard ECG tracing, the P wave corresponds to which physiological
event?
A. Ventricular depolarization
B. Atrial depolarization [CORRECT]
C. Ventricular repolarization
D. Atrial repolarization
Correct Answer: B
Rationale: Correct because the P wave represents the wave of depolarization
spreading through the atria, triggering atrial contraction.
Q5: If a patient has a heart rate of 75 beats per minute and an end-diastolic volume
of 140 mL with an end-systolic volume of 70 mL, what is the cardiac output?
A. 5.25 L/min [CORRECT]
B. 7.0 L/min
C. 10.5 L/min
D. 15.0 L/min
Correct Answer: A
Rationale: Correct because stroke volume = EDV − ESV = 140 − 70 = 70 mL; cardiac
output = SV × HR = 70 mL × 75 = 5,250 mL/min = 5.25 L/min.
Q6: Which layer of a blood vessel contains the smooth muscle and elastic fibers that
allow vasoconstriction and vasodilation?
A. Tunica intima
B. Tunica media [CORRECT]
C. Tunica externa
D. Tunica adventitia
Correct Answer: B
Rationale: Correct because the tunica media is the middle layer containing circular
smooth muscle and elastic tissue, which regulates vessel diameter and blood flow.
Q7: Arterioles are considered the primary site of which physiological function?
A. Blood reservoir storage
B. Exchange of gases and nutrients
C. Peripheral resistance regulation [CORRECT]
D. One-way blood return to the heart
, Correct Answer: C
Rationale: Correct because arterioles have thick muscular walls relative to their
diameter and are the major resistance vessels that control blood flow into capillary
beds.
Q8: According to the Starling forces, which pressure promotes fluid movement out of
the capillary at the arterial end?
A. Interstitial fluid hydrostatic pressure
B. Blood colloid osmotic pressure
C. Capillary hydrostatic pressure [CORRECT]
D. Interstitial fluid osmotic pressure
Correct Answer: C
Rationale: Correct because capillary hydrostatic pressure (blood pressure) is the
main filtration force that pushes fluid and solutes out of the capillary into the
interstitial space.
Q9: A sudden increase in blood pressure triggers baroreceptors in the carotid
sinuses. Which response occurs to restore homeostasis?
A. Increased sympathetic stimulation of the heart
B. Increased heart rate and contractility
C. Decreased parasympathetic stimulation of the SA node
D. Vasodilation and decreased cardiac output [CORRECT]
Correct Answer: D
Rationale: Correct because elevated baroreceptor firing inhibits sympathetic output
and enhances parasympathetic tone, resulting in vasodilation, bradycardia, and
reduced cardiac output to lower blood pressure.
Q10: (Data Question) A patient has the following hemodynamic measurements:
mean arterial pressure = 93 mmHg, central venous pressure = 2 mmHg, and cardiac
output = 5.0 L/min. What is the total peripheral resistance (TPR)?
A. 12.4 mmHg·min/L
B. 15.6 mmHg·min/L
C. 18.2 mmHg·min/L [CORRECT]
D. 22.8 mmHg·min/L
Correct Answer: C
Rationale: Correct because TPR = (MAP − CVP)/CO = (93 − 2)/5.0 = 91/5.0 = 18.2
mmHg·min/L, reflecting the resistance the heart must overcome to perfuse tissues.
