NR 507 Exam 2 Actual Exam V3 | NR 507 Advanced Pathophysiology
(NR507 Exam 2) [PDF] | Chamberlain University
1. A 68-year-old patient with chronic hypertension presents with signs of left heart failure.
Which mechanism primarily contributes to the increased myocardial oxygen demand in this
patient?
A. Decreased systemic vascular resistance
B. Decreased left ventricular end-diastolic volume
C. Increased afterload from peripheral vasoconstriction
D. Increased parasympathetic stimulation
Answer: C
Rationale: Chronic hypertension increases systemic vascular resistance, which directly
raises the afterload the left ventricle must overcome to eject blood. This increased
workload forces the myocardium to consume more oxygen to maintain cardiac output.
Over time, this stress leads to compensatory hypertrophy and eventual heart failure.
2. A patient is diagnosed with a massive pulmonary embolism. Which of the following
ventilation-perfusion (V/Q) abnormalities is most likely occurring in the affected lung
segments?
A. Low V/Q ratio (Shunt)
B. Silent unit (no ventilation or perfusion)
C. Normal V/Q ratio
D. High V/Q ratio (Dead space)
Answer: D
Rationale: A pulmonary embolism obstructs blood flow to the alveoli, creating an area that
is ventilated but not perfused. This condition is known as alveolar dead space, represented
by a high V/Q ratio. This mismatch prevents gas exchange in the affected areas, leading to
acute hypoxemia.
3. In the early stages of septic shock, why does a patient often exhibit a high cardiac output
and low systemic vascular resistance?
A. Compensatory vasoconstriction due to catecholamine release
B. Profound vasodilation caused by inflammatory mediators
C. Increased blood viscosity from capillary leak
D. Primary myocardial depression from bacterial toxins
,Answer: B
Rationale: Sepsis triggers a systemic inflammatory response that releases mediators like
nitric oxide, causing profound peripheral vasodilation. This reduction in systemic vascular
resistance (SVR) initially leads to a compensatory increase in heart rate and stroke volume,
resulting in a high cardiac output state often called ‘warm shock’. This hemodynamic
profile distinguishes early distributive shock from hypovolemic or cardiogenic shock.
4. Which statement best describes the Bohr effect in the context of oxygen transport to
tissues?
A. Increased pH shifts the oxyhemoglobin curve to the right
B. Decreased pH and increased PCO2 decrease hemoglobin’s affinity for oxygen
C. Decreased PCO2 increases oxygen unloading at the tissue level
D. Lower temperatures enhance oxygen release from hemoglobin
Answer: B
Rationale: The Bohr effect describes how hydrogen ions (low pH) and carbon dioxide
affect hemoglobin’s affinity for oxygen. In metabolically active tissues, high levels of CO2
and H+ cause the oxyhemoglobin dissociation curve to shift to the right. This physiological
response facilitates the unloading of oxygen where it is most needed for cellular
respiration.
5. A patient presents with arterial blood gas results: pH 7.30, PaCO2 55 mmHg, and HCO3 26
mEq/L. Which of the following is the most likely cause?
A. Respiratory alkalosis from hyperventilation
B. Compensated metabolic acidosis
C. Acute respiratory acidosis due to hypoventilation
D. Chronic metabolic alkalosis with respiratory compensation
Answer: C
Rationale: The pH is low, indicating acidosis, and the PaCO2 is high, indicating a
respiratory cause. Since the bicarbonate is within or near the normal range, the body has
not yet significantly compensated for the imbalance. This pattern is characteristic of acute
hypoventilation, which could be caused by CNS depression or obstructive airway disease.
6. What is the primary pathophysiology behind the development of Disseminated
Intravascular Coagulation (DIC)?
A. Selective inhibition of the fibrinolytic system
B. Isolated deficiency of Vitamin K-dependent factors
C. Increased platelet production by the bone marrow
, D. Systemic activation of the coagulation cascade resulting in microthrombi
Answer: D
Rationale: DIC involves the widespread, systemic activation of coagulation, typically
triggered by sepsis, trauma, or malignancy. This results in the formation of microthrombi
throughout the microvasculature, consuming platelets and clotting factors. Consequently,
the patient is paradoxically at high risk for both thrombosis and severe hemorrhage.
7. During an acute myocardial infarction, how does the release of catecholamines affect the
heart’s workload?
A. It decreases heart rate to allow for better filling
B. It increases heart rate and contractility, further increasing oxygen demand
C. It promotes coronary vasodilation to improve perfusion
D. It reduces afterload by dilating peripheral arteries
Answer: B
Rationale: The stress of a myocardial infarction triggers a sympathetic nervous system
response, releasing epinephrine and norepinephrine. These catecholamines increase heart
rate and myocardial contractility via beta-1 receptors. While this is a compensatory
attempt to maintain cardiac output, it significantly increases the oxygen demand of already
ischemic tissue, potentially expanding the area of injury.
8. A patient with chronic obstructive pulmonary disease (COPD) develops pulmonary
hypertension. What is the most likely underlying mechanism?
A. Left-sided heart failure causing venous congestion
B. Excessive production of nitric oxide by the pulmonary endothelium
C. Hypoxic pulmonary vasoconstriction in response to chronic alveolar hypoxia
D. Decreased pulmonary vascular resistance from capillary recruitment
Answer: C
Rationale: In COPD, chronic alveolar hypoxia triggers the pulmonary arteries to constrict
in an effort to divert blood to better-ventilated areas. This hypoxic pulmonary
vasoconstriction, when widespread and chronic, leads to permanent structural remodeling
of the vessels. The resulting increase in pulmonary vascular resistance causes pulmonary
hypertension and can eventually lead to right heart failure (cor pulmonale).
9. A patient with severe burns is at high risk for which type of shock?
A. Cardiogenic shock
B. Neurogenic shock
(NR507 Exam 2) [PDF] | Chamberlain University
1. A 68-year-old patient with chronic hypertension presents with signs of left heart failure.
Which mechanism primarily contributes to the increased myocardial oxygen demand in this
patient?
A. Decreased systemic vascular resistance
B. Decreased left ventricular end-diastolic volume
C. Increased afterload from peripheral vasoconstriction
D. Increased parasympathetic stimulation
Answer: C
Rationale: Chronic hypertension increases systemic vascular resistance, which directly
raises the afterload the left ventricle must overcome to eject blood. This increased
workload forces the myocardium to consume more oxygen to maintain cardiac output.
Over time, this stress leads to compensatory hypertrophy and eventual heart failure.
2. A patient is diagnosed with a massive pulmonary embolism. Which of the following
ventilation-perfusion (V/Q) abnormalities is most likely occurring in the affected lung
segments?
A. Low V/Q ratio (Shunt)
B. Silent unit (no ventilation or perfusion)
C. Normal V/Q ratio
D. High V/Q ratio (Dead space)
Answer: D
Rationale: A pulmonary embolism obstructs blood flow to the alveoli, creating an area that
is ventilated but not perfused. This condition is known as alveolar dead space, represented
by a high V/Q ratio. This mismatch prevents gas exchange in the affected areas, leading to
acute hypoxemia.
3. In the early stages of septic shock, why does a patient often exhibit a high cardiac output
and low systemic vascular resistance?
A. Compensatory vasoconstriction due to catecholamine release
B. Profound vasodilation caused by inflammatory mediators
C. Increased blood viscosity from capillary leak
D. Primary myocardial depression from bacterial toxins
,Answer: B
Rationale: Sepsis triggers a systemic inflammatory response that releases mediators like
nitric oxide, causing profound peripheral vasodilation. This reduction in systemic vascular
resistance (SVR) initially leads to a compensatory increase in heart rate and stroke volume,
resulting in a high cardiac output state often called ‘warm shock’. This hemodynamic
profile distinguishes early distributive shock from hypovolemic or cardiogenic shock.
4. Which statement best describes the Bohr effect in the context of oxygen transport to
tissues?
A. Increased pH shifts the oxyhemoglobin curve to the right
B. Decreased pH and increased PCO2 decrease hemoglobin’s affinity for oxygen
C. Decreased PCO2 increases oxygen unloading at the tissue level
D. Lower temperatures enhance oxygen release from hemoglobin
Answer: B
Rationale: The Bohr effect describes how hydrogen ions (low pH) and carbon dioxide
affect hemoglobin’s affinity for oxygen. In metabolically active tissues, high levels of CO2
and H+ cause the oxyhemoglobin dissociation curve to shift to the right. This physiological
response facilitates the unloading of oxygen where it is most needed for cellular
respiration.
5. A patient presents with arterial blood gas results: pH 7.30, PaCO2 55 mmHg, and HCO3 26
mEq/L. Which of the following is the most likely cause?
A. Respiratory alkalosis from hyperventilation
B. Compensated metabolic acidosis
C. Acute respiratory acidosis due to hypoventilation
D. Chronic metabolic alkalosis with respiratory compensation
Answer: C
Rationale: The pH is low, indicating acidosis, and the PaCO2 is high, indicating a
respiratory cause. Since the bicarbonate is within or near the normal range, the body has
not yet significantly compensated for the imbalance. This pattern is characteristic of acute
hypoventilation, which could be caused by CNS depression or obstructive airway disease.
6. What is the primary pathophysiology behind the development of Disseminated
Intravascular Coagulation (DIC)?
A. Selective inhibition of the fibrinolytic system
B. Isolated deficiency of Vitamin K-dependent factors
C. Increased platelet production by the bone marrow
, D. Systemic activation of the coagulation cascade resulting in microthrombi
Answer: D
Rationale: DIC involves the widespread, systemic activation of coagulation, typically
triggered by sepsis, trauma, or malignancy. This results in the formation of microthrombi
throughout the microvasculature, consuming platelets and clotting factors. Consequently,
the patient is paradoxically at high risk for both thrombosis and severe hemorrhage.
7. During an acute myocardial infarction, how does the release of catecholamines affect the
heart’s workload?
A. It decreases heart rate to allow for better filling
B. It increases heart rate and contractility, further increasing oxygen demand
C. It promotes coronary vasodilation to improve perfusion
D. It reduces afterload by dilating peripheral arteries
Answer: B
Rationale: The stress of a myocardial infarction triggers a sympathetic nervous system
response, releasing epinephrine and norepinephrine. These catecholamines increase heart
rate and myocardial contractility via beta-1 receptors. While this is a compensatory
attempt to maintain cardiac output, it significantly increases the oxygen demand of already
ischemic tissue, potentially expanding the area of injury.
8. A patient with chronic obstructive pulmonary disease (COPD) develops pulmonary
hypertension. What is the most likely underlying mechanism?
A. Left-sided heart failure causing venous congestion
B. Excessive production of nitric oxide by the pulmonary endothelium
C. Hypoxic pulmonary vasoconstriction in response to chronic alveolar hypoxia
D. Decreased pulmonary vascular resistance from capillary recruitment
Answer: C
Rationale: In COPD, chronic alveolar hypoxia triggers the pulmonary arteries to constrict
in an effort to divert blood to better-ventilated areas. This hypoxic pulmonary
vasoconstriction, when widespread and chronic, leads to permanent structural remodeling
of the vessels. The resulting increase in pulmonary vascular resistance causes pulmonary
hypertension and can eventually lead to right heart failure (cor pulmonale).
9. A patient with severe burns is at high risk for which type of shock?
A. Cardiogenic shock
B. Neurogenic shock
