Comprehensive Pathophysiology and NR283
Exam Practice Exam – Updated 2026
(Graded A+)
Subject: Pathophysiology
Subtopic: Alterations in Fluid, Electrolyte, and Acid-Base Balance
Question 1: A 72-year-old patient with prolonged nasogastric suction develops weakness,
confusion, and shallow respirations. Arterial blood gases reveal pH 7.50, PaCO₂ 48 mmHg, and
HCO₃⁻ 36 mEq/L. Which compensatory response is most consistent with this disorder?
A) Increased respiratory rate resulting in decreased PaCO₂
B) Renal excretion of hydrogen ions with bicarbonate retention
C) Hypoventilation leading to carbon dioxide retention
D) Hyperventilation with increased oxygen consumption
Correct Answer: C - Hypoventilation leading to carbon dioxide retention
Rationale: The patient has metabolic alkalosis (elevated pH and HCO₃⁻). The primary
compensatory mechanism is hypoventilation, which retains CO₂ and increases carbonic acid
concentration. Option A would worsen alkalosis. Option B describes mechanisms that promote
alkalosis rather than compensate for it. Option D would further decrease carbonic acid and
exacerbate the alkalosis.
Question 2: A patient with severe diarrhea is most likely to develop which acid-base imbalance?
A) Respiratory acidosis
B) Metabolic acidosis due to bicarbonate loss
C) Metabolic alkalosis due to hydrogen ion loss
D) Respiratory alkalosis secondary to hyperventilation
Correct Answer: B - Metabolic acidosis due to bicarbonate loss
Rationale: Diarrhea causes significant loss of bicarbonate-rich intestinal secretions, producing
metabolic acidosis. Respiratory disorders are not primary consequences of diarrhea. Metabolic
alkalosis is more commonly associated with gastric fluid loss, such as vomiting or nasogastric
suction.
Question 3: A nurse notes flattened T waves, muscle weakness, and decreased bowel sounds in a
hospitalized patient. Which electrolyte imbalance is most likely present?
A) Hyperkalemia
B) Hypercalcemia
,C) Hypokalemia
D) Hyponatremia
Correct Answer: C - Hypokalemia
Rationale: Hypokalemia classically presents with muscle weakness, ileus, and ECG changes
including flattened T waves and U waves. Hyperkalemia typically produces peaked T waves.
Hypercalcemia and hyponatremia do not consistently produce this constellation of findings.
Question 4: A patient with syndrome of inappropriate antidiuretic hormone secretion (SIADH)
would be expected to demonstrate:
A) Hypernatremia with increased serum osmolality
B) Hyponatremia with decreased serum osmolality
C) Hyperkalemia with increased urine output
D) Hypocalcemia with metabolic alkalosis
Correct Answer: B - Hyponatremia with decreased serum osmolality
Rationale: SIADH causes excessive water retention, leading to dilutional hyponatremia and
decreased serum osmolality. Urine output is typically reduced, not increased. Potassium and
calcium abnormalities are not defining features of SIADH.
Question 5: A patient develops respiratory acidosis following opioid overdose. Which
pathophysiologic mechanism is responsible?
A) Increased renal bicarbonate excretion
B) Excessive loss of bicarbonate through the gastrointestinal tract
C) Alveolar hypoventilation causing carbon dioxide retention
D) Increased production of lactic acid
Correct Answer: C - Alveolar hypoventilation causing carbon dioxide retention
Rationale: Opioids depress the respiratory center, resulting in hypoventilation and retention of
CO₂, producing respiratory acidosis. Gastrointestinal bicarbonate loss causes metabolic
acidosis, while lactic acid accumulation represents a metabolic process.
Subtopic: Cellular Injury, Inflammation, and Immunity
Question 6: Reversible cellular injury is most commonly characterized by:
A) Cellular swelling due to ATP depletion
B) Nuclear fragmentation and membrane rupture
,C) Mitochondrial calcification
D) Extensive lysosomal destruction
Correct Answer: A - Cellular swelling due to ATP depletion
Rationale: Early reversible injury results from ATP depletion, impairing sodium-potassium
pumps and causing cellular swelling. Nuclear fragmentation and membrane rupture indicate
irreversible injury. Calcification and extensive lysosomal destruction occur later in severe
injury.
Question 7: Which event is considered a hallmark of apoptosis rather than necrosis?
A) Cellular swelling and inflammation
B) Membrane rupture with leakage of intracellular contents
C) Programmed cell death without inflammation
D) Random destruction of adjacent tissue
Correct Answer: C - Programmed cell death without inflammation
Rationale: Apoptosis is an organized, energy-dependent process causing minimal inflammation.
Necrosis involves membrane disruption, cellular swelling, and inflammatory responses.
Question 8: During acute inflammation, which mediator is primarily responsible for vasodilation
and increased capillary permeability?
A) Histamine
B) Erythropoietin
C) Albumin
D) Insulin
Correct Answer: A - Histamine
Rationale: Histamine released from mast cells promotes vasodilation and increased vascular
permeability during inflammation. The remaining substances do not play primary inflammatory
mediator roles.
Question 9: A patient experiences anaphylaxis after administration of penicillin. This reaction is
classified as:
A) Type I hypersensitivity
B) Type II hypersensitivity
C) Type III hypersensitivity
D) Type IV hypersensitivity
Correct Answer: A - Type I hypersensitivity
, Rationale: Anaphylaxis is an IgE-mediated immediate hypersensitivity reaction (Type I). Type II
reactions involve cytotoxic antibodies, Type III involves immune complexes, and Type IV
reactions are delayed T-cell mediated responses.
Question 10: Which leukocyte is most strongly associated with parasitic infections and allergic
disorders?
A) Neutrophil
B) Basophil
C) Eosinophil
D) Monocyte
Correct Answer: C - Eosinophil
Rationale: Eosinophils play major roles in parasitic defense and allergic responses. Neutrophils
primarily respond to bacterial infections, while monocytes and basophils serve different
immunologic functions.
Subtopic: Cardiovascular Disorders
Question 11: The primary pathophysiologic event underlying heart failure is:
A) Inability of the heart to pump sufficient blood to meet metabolic demands
B) Complete cessation of myocardial electrical activity
C) Increased erythrocyte production
D) Excessive systemic vasodilation without cardiac dysfunction
Correct Answer: A - Inability of the heart to pump sufficient blood to meet metabolic
demands
Rationale: Heart failure occurs when cardiac output is inadequate to satisfy tissue metabolic
needs. Electrical activity usually persists, and vasodilation alone does not define heart failure.
Question 12: A patient with left-sided heart failure is most likely to exhibit:
A) Peripheral edema only
B) Pulmonary congestion and dyspnea
C) Hepatomegaly without respiratory symptoms
D) Splenomegaly as the earliest sign
Correct Answer: B - Pulmonary congestion and dyspnea
Exam Practice Exam – Updated 2026
(Graded A+)
Subject: Pathophysiology
Subtopic: Alterations in Fluid, Electrolyte, and Acid-Base Balance
Question 1: A 72-year-old patient with prolonged nasogastric suction develops weakness,
confusion, and shallow respirations. Arterial blood gases reveal pH 7.50, PaCO₂ 48 mmHg, and
HCO₃⁻ 36 mEq/L. Which compensatory response is most consistent with this disorder?
A) Increased respiratory rate resulting in decreased PaCO₂
B) Renal excretion of hydrogen ions with bicarbonate retention
C) Hypoventilation leading to carbon dioxide retention
D) Hyperventilation with increased oxygen consumption
Correct Answer: C - Hypoventilation leading to carbon dioxide retention
Rationale: The patient has metabolic alkalosis (elevated pH and HCO₃⁻). The primary
compensatory mechanism is hypoventilation, which retains CO₂ and increases carbonic acid
concentration. Option A would worsen alkalosis. Option B describes mechanisms that promote
alkalosis rather than compensate for it. Option D would further decrease carbonic acid and
exacerbate the alkalosis.
Question 2: A patient with severe diarrhea is most likely to develop which acid-base imbalance?
A) Respiratory acidosis
B) Metabolic acidosis due to bicarbonate loss
C) Metabolic alkalosis due to hydrogen ion loss
D) Respiratory alkalosis secondary to hyperventilation
Correct Answer: B - Metabolic acidosis due to bicarbonate loss
Rationale: Diarrhea causes significant loss of bicarbonate-rich intestinal secretions, producing
metabolic acidosis. Respiratory disorders are not primary consequences of diarrhea. Metabolic
alkalosis is more commonly associated with gastric fluid loss, such as vomiting or nasogastric
suction.
Question 3: A nurse notes flattened T waves, muscle weakness, and decreased bowel sounds in a
hospitalized patient. Which electrolyte imbalance is most likely present?
A) Hyperkalemia
B) Hypercalcemia
,C) Hypokalemia
D) Hyponatremia
Correct Answer: C - Hypokalemia
Rationale: Hypokalemia classically presents with muscle weakness, ileus, and ECG changes
including flattened T waves and U waves. Hyperkalemia typically produces peaked T waves.
Hypercalcemia and hyponatremia do not consistently produce this constellation of findings.
Question 4: A patient with syndrome of inappropriate antidiuretic hormone secretion (SIADH)
would be expected to demonstrate:
A) Hypernatremia with increased serum osmolality
B) Hyponatremia with decreased serum osmolality
C) Hyperkalemia with increased urine output
D) Hypocalcemia with metabolic alkalosis
Correct Answer: B - Hyponatremia with decreased serum osmolality
Rationale: SIADH causes excessive water retention, leading to dilutional hyponatremia and
decreased serum osmolality. Urine output is typically reduced, not increased. Potassium and
calcium abnormalities are not defining features of SIADH.
Question 5: A patient develops respiratory acidosis following opioid overdose. Which
pathophysiologic mechanism is responsible?
A) Increased renal bicarbonate excretion
B) Excessive loss of bicarbonate through the gastrointestinal tract
C) Alveolar hypoventilation causing carbon dioxide retention
D) Increased production of lactic acid
Correct Answer: C - Alveolar hypoventilation causing carbon dioxide retention
Rationale: Opioids depress the respiratory center, resulting in hypoventilation and retention of
CO₂, producing respiratory acidosis. Gastrointestinal bicarbonate loss causes metabolic
acidosis, while lactic acid accumulation represents a metabolic process.
Subtopic: Cellular Injury, Inflammation, and Immunity
Question 6: Reversible cellular injury is most commonly characterized by:
A) Cellular swelling due to ATP depletion
B) Nuclear fragmentation and membrane rupture
,C) Mitochondrial calcification
D) Extensive lysosomal destruction
Correct Answer: A - Cellular swelling due to ATP depletion
Rationale: Early reversible injury results from ATP depletion, impairing sodium-potassium
pumps and causing cellular swelling. Nuclear fragmentation and membrane rupture indicate
irreversible injury. Calcification and extensive lysosomal destruction occur later in severe
injury.
Question 7: Which event is considered a hallmark of apoptosis rather than necrosis?
A) Cellular swelling and inflammation
B) Membrane rupture with leakage of intracellular contents
C) Programmed cell death without inflammation
D) Random destruction of adjacent tissue
Correct Answer: C - Programmed cell death without inflammation
Rationale: Apoptosis is an organized, energy-dependent process causing minimal inflammation.
Necrosis involves membrane disruption, cellular swelling, and inflammatory responses.
Question 8: During acute inflammation, which mediator is primarily responsible for vasodilation
and increased capillary permeability?
A) Histamine
B) Erythropoietin
C) Albumin
D) Insulin
Correct Answer: A - Histamine
Rationale: Histamine released from mast cells promotes vasodilation and increased vascular
permeability during inflammation. The remaining substances do not play primary inflammatory
mediator roles.
Question 9: A patient experiences anaphylaxis after administration of penicillin. This reaction is
classified as:
A) Type I hypersensitivity
B) Type II hypersensitivity
C) Type III hypersensitivity
D) Type IV hypersensitivity
Correct Answer: A - Type I hypersensitivity
, Rationale: Anaphylaxis is an IgE-mediated immediate hypersensitivity reaction (Type I). Type II
reactions involve cytotoxic antibodies, Type III involves immune complexes, and Type IV
reactions are delayed T-cell mediated responses.
Question 10: Which leukocyte is most strongly associated with parasitic infections and allergic
disorders?
A) Neutrophil
B) Basophil
C) Eosinophil
D) Monocyte
Correct Answer: C - Eosinophil
Rationale: Eosinophils play major roles in parasitic defense and allergic responses. Neutrophils
primarily respond to bacterial infections, while monocytes and basophils serve different
immunologic functions.
Subtopic: Cardiovascular Disorders
Question 11: The primary pathophysiologic event underlying heart failure is:
A) Inability of the heart to pump sufficient blood to meet metabolic demands
B) Complete cessation of myocardial electrical activity
C) Increased erythrocyte production
D) Excessive systemic vasodilation without cardiac dysfunction
Correct Answer: A - Inability of the heart to pump sufficient blood to meet metabolic
demands
Rationale: Heart failure occurs when cardiac output is inadequate to satisfy tissue metabolic
needs. Electrical activity usually persists, and vasodilation alone does not define heart failure.
Question 12: A patient with left-sided heart failure is most likely to exhibit:
A) Peripheral edema only
B) Pulmonary congestion and dyspnea
C) Hepatomegaly without respiratory symptoms
D) Splenomegaly as the earliest sign
Correct Answer: B - Pulmonary congestion and dyspnea
