NSG 530 Exam 2 Actual Exam V3 | NSG 530 Advanced
Pathophysiology (NSG530 Exam 2) [PDF] | Wilkes University
1. A 68-year-old patient with chronic hypertension presents with signs of left ventricular
failure. Which pathophysiological change in the endothelium most directly contributes to
increased systemic vascular resistance in this patient?
A. Increased production of Nitric Oxide
B. Downregulation of Endothelin-1 receptors
C. Reduced bioavailability of Nitric Oxide due to reactive oxygen species
D. Increased synthesis of prostacyclin
Answer: C
Rationale: Endothelial dysfunction in hypertension is often characterized by oxidative
stress, where reactive oxygen species (ROS) neutralize nitric oxide. This loss of a potent
vasodilator leads to impaired vasodilation and increased systemic vascular resistance. Over
time, this process contributes to the structural remodeling of the vasculature and
exacerbates afterload on the heart.
2. Which of the following factors is most critical in the initial formation of a venous thrombus
according to Virchow’s Triad?
A. Stasis of blood flow
B. High shear stress in the arterial system
C. Decreased platelet count
D. Increased Vitamin K levels
Answer: A
Rationale: Virchow’s Triad identifies three categories of factors that contribute to
thrombosis: stasis, endothelial injury, and hypercoagulability. In the venous system, stasis
of blood flow allows for the accumulation of clotting factors and prevents their dilution by
fresh blood. This environment significantly promotes the formation of a thrombus,
particularly in deep veins during periods of immobility.
3. A patient is diagnosed with severe aortic stenosis. How does this condition primarily affect
the components of cardiac output?
A. Increases preload by reducing venous return
B. Increases afterload, leading to left ventricular hypertrophy
C. Decreases contractility via the Frank-Starling mechanism
,D. Decreases heart rate to compensate for pressure overload
Answer: B
Rationale: Aortic stenosis creates a mechanical obstruction to blood flow leaving the left
ventricle, which significantly increases the afterload the ventricle must overcome. The
myocardium responds to this chronic pressure overload by developing concentric
hypertrophy to maintain wall stress. Eventually, this compensatory mechanism may fail,
leading to reduced stroke volume and heart failure.
4. In a patient with Acute Respiratory Distress Syndrome (ARDS), what is the primary
mechanism leading to severe hypoxemia?
A. Right-to-left intrapulmonary shunting
B. Alveolar dead space ventilation
C. Increased lung compliance
D. Respiratory alkalosis due to hypoventilation
Answer: A
Rationale: ARDS involves widespread inflammation and damage to the alveolar-capillary
membrane, leading to protein-rich fluid filling the alveoli. This results in areas of the lung
being perfused but not ventilated, known as a right-to-left intrapulmonary shunt. Because
the blood bypassing these alveoli is not oxygenated, the resulting hypoxemia is typically
refractory to supplemental oxygen therapy.
5. A 55-year-old male with a history of smoking presents with a pH of 7.32, PaCO2 of 55
mmHg, and HCO3 of 28 mEq/L. How would you describe this acid-base status?
A. Metabolic acidosis with respiratory compensation
B. Respiratory alkalosis with renal compensation
C. Fully compensated metabolic alkalosis
D. Respiratory acidosis with partial renal compensation
Answer: D
Rationale: The pH is below 7.35, indicating acidosis, and the PaCO2 is elevated above 45
mmHg, identifying the cause as respiratory. The HCO3 is slightly elevated above the normal
range of 22-26 mEq/L, suggesting the kidneys have begun to retain bicarbonate to
compensate. However, because the pH has not returned to the normal range, the
compensation is only partial.
6. Which compensatory mechanism is activated in response to a sudden decrease in mean
arterial pressure (MAP)?
A. Inhibition of the Renin-Angiotensin-Aldosterone System (RAAS)
, B. Parasympathetic stimulation of the sinoatrial node
C. Release of Atrial Natriuretic Peptide (ANP)
D. Activation of the baroreceptor reflex
Answer: D
Rationale: The baroreceptor reflex is a rapid-response mechanism triggered by a decrease
in stretch within the carotid sinuses and aortic arch. This leads to increased sympathetic
outflow, which increases heart rate, contractility, and peripheral vasoconstriction. These
actions collectively work to restore mean arterial pressure and maintain perfusion to vital
organs.
7. What is the role of B-type Natriuretic Peptide (BNP) in the pathophysiology of heart
failure?
A. It causes peripheral vasoconstriction to increase blood pressure
B. It promotes diuresis and vasodilation to reduce ventricular wall stretch
C. It promotes sodium and water retention to increase preload
D. It increases heart rate by stimulating the sympathetic nervous system
Answer: B
Rationale: BNP is synthesized and released by the ventricles in response to increased wall
tension and volume overload. Its primary actions include promoting natriuresis (sodium
excretion) and diuresis, as well as inducing systemic vasodilation. By antagonizing the
effects of the RAAS and SNS, BNP serves as a crucial compensatory hormone to reduce
cardiac workload.
8. During exercise, how does the body ensure adequate oxygen delivery to skeletal muscles?
A. Leftward shift of the oxyhemoglobin dissociation curve
B. Rightward shift of the oxyhemoglobin dissociation curve
C. Decreased production of 2,3-DPG
D. Reduced cardiac output to preserve energy
Answer: B
Rationale: During exercise, increased CO2 production, local acidosis (low pH), and rising
temperatures occur in active tissues. These conditions cause a rightward shift in the
oxyhemoglobin dissociation curve, known as the Bohr effect. This shift decreases
hemoglobin’s affinity for oxygen, facilitating the release of oxygen to the tissues that need it
most.
Pathophysiology (NSG530 Exam 2) [PDF] | Wilkes University
1. A 68-year-old patient with chronic hypertension presents with signs of left ventricular
failure. Which pathophysiological change in the endothelium most directly contributes to
increased systemic vascular resistance in this patient?
A. Increased production of Nitric Oxide
B. Downregulation of Endothelin-1 receptors
C. Reduced bioavailability of Nitric Oxide due to reactive oxygen species
D. Increased synthesis of prostacyclin
Answer: C
Rationale: Endothelial dysfunction in hypertension is often characterized by oxidative
stress, where reactive oxygen species (ROS) neutralize nitric oxide. This loss of a potent
vasodilator leads to impaired vasodilation and increased systemic vascular resistance. Over
time, this process contributes to the structural remodeling of the vasculature and
exacerbates afterload on the heart.
2. Which of the following factors is most critical in the initial formation of a venous thrombus
according to Virchow’s Triad?
A. Stasis of blood flow
B. High shear stress in the arterial system
C. Decreased platelet count
D. Increased Vitamin K levels
Answer: A
Rationale: Virchow’s Triad identifies three categories of factors that contribute to
thrombosis: stasis, endothelial injury, and hypercoagulability. In the venous system, stasis
of blood flow allows for the accumulation of clotting factors and prevents their dilution by
fresh blood. This environment significantly promotes the formation of a thrombus,
particularly in deep veins during periods of immobility.
3. A patient is diagnosed with severe aortic stenosis. How does this condition primarily affect
the components of cardiac output?
A. Increases preload by reducing venous return
B. Increases afterload, leading to left ventricular hypertrophy
C. Decreases contractility via the Frank-Starling mechanism
,D. Decreases heart rate to compensate for pressure overload
Answer: B
Rationale: Aortic stenosis creates a mechanical obstruction to blood flow leaving the left
ventricle, which significantly increases the afterload the ventricle must overcome. The
myocardium responds to this chronic pressure overload by developing concentric
hypertrophy to maintain wall stress. Eventually, this compensatory mechanism may fail,
leading to reduced stroke volume and heart failure.
4. In a patient with Acute Respiratory Distress Syndrome (ARDS), what is the primary
mechanism leading to severe hypoxemia?
A. Right-to-left intrapulmonary shunting
B. Alveolar dead space ventilation
C. Increased lung compliance
D. Respiratory alkalosis due to hypoventilation
Answer: A
Rationale: ARDS involves widespread inflammation and damage to the alveolar-capillary
membrane, leading to protein-rich fluid filling the alveoli. This results in areas of the lung
being perfused but not ventilated, known as a right-to-left intrapulmonary shunt. Because
the blood bypassing these alveoli is not oxygenated, the resulting hypoxemia is typically
refractory to supplemental oxygen therapy.
5. A 55-year-old male with a history of smoking presents with a pH of 7.32, PaCO2 of 55
mmHg, and HCO3 of 28 mEq/L. How would you describe this acid-base status?
A. Metabolic acidosis with respiratory compensation
B. Respiratory alkalosis with renal compensation
C. Fully compensated metabolic alkalosis
D. Respiratory acidosis with partial renal compensation
Answer: D
Rationale: The pH is below 7.35, indicating acidosis, and the PaCO2 is elevated above 45
mmHg, identifying the cause as respiratory. The HCO3 is slightly elevated above the normal
range of 22-26 mEq/L, suggesting the kidneys have begun to retain bicarbonate to
compensate. However, because the pH has not returned to the normal range, the
compensation is only partial.
6. Which compensatory mechanism is activated in response to a sudden decrease in mean
arterial pressure (MAP)?
A. Inhibition of the Renin-Angiotensin-Aldosterone System (RAAS)
, B. Parasympathetic stimulation of the sinoatrial node
C. Release of Atrial Natriuretic Peptide (ANP)
D. Activation of the baroreceptor reflex
Answer: D
Rationale: The baroreceptor reflex is a rapid-response mechanism triggered by a decrease
in stretch within the carotid sinuses and aortic arch. This leads to increased sympathetic
outflow, which increases heart rate, contractility, and peripheral vasoconstriction. These
actions collectively work to restore mean arterial pressure and maintain perfusion to vital
organs.
7. What is the role of B-type Natriuretic Peptide (BNP) in the pathophysiology of heart
failure?
A. It causes peripheral vasoconstriction to increase blood pressure
B. It promotes diuresis and vasodilation to reduce ventricular wall stretch
C. It promotes sodium and water retention to increase preload
D. It increases heart rate by stimulating the sympathetic nervous system
Answer: B
Rationale: BNP is synthesized and released by the ventricles in response to increased wall
tension and volume overload. Its primary actions include promoting natriuresis (sodium
excretion) and diuresis, as well as inducing systemic vasodilation. By antagonizing the
effects of the RAAS and SNS, BNP serves as a crucial compensatory hormone to reduce
cardiac workload.
8. During exercise, how does the body ensure adequate oxygen delivery to skeletal muscles?
A. Leftward shift of the oxyhemoglobin dissociation curve
B. Rightward shift of the oxyhemoglobin dissociation curve
C. Decreased production of 2,3-DPG
D. Reduced cardiac output to preserve energy
Answer: B
Rationale: During exercise, increased CO2 production, local acidosis (low pH), and rising
temperatures occur in active tissues. These conditions cause a rightward shift in the
oxyhemoglobin dissociation curve, known as the Bohr effect. This shift decreases
hemoglobin’s affinity for oxygen, facilitating the release of oxygen to the tissues that need it
most.
