NR283 Exam 2 Pathophysiology
2026/2027 | Verified Q&A +
Rationales | Chamberlain A+ Guide
Guaranteed Pass (GRADED A+)
Question 1
A patient with systemic lupus erythematosus (SLE) develops
hemolytic anemia, thrombocytopenia, and renal injury. Which
mechanism best explains this constellation of findings?
A. IgE-mediated mast cell degranulation
B. Immune complex deposition activating complement
C. Antibody-mediated cellular destruction via Fc receptors
D. T-cell mediated direct cytotoxicity
Rationale: SLE is the prototypic type III hypersensitivity disorder.
Circulating immune complexes deposit in tissues such as the kidney
and blood vessels, then activate complement, producing
inflammation and cell destruction. Type I (IgE), type II (antibody
against fixed antigens), and type IV (T-cell) mechanisms do not
explain the multisystem pattern seen in SLE .
Question 2
,Which laboratory pattern most strongly suggests disseminated
intravascular coagulation (DIC) rather than immune
thrombocytopenic purpura (ITP)?
A. Isolated thrombocytopenia with normal PT/PTT and elevated
bleeding time
B. Thrombocytopenia with prolonged PT/PTT, low fibrinogen,
and elevated D-dimer
C. Thrombocytosis with elevated von Willebrand factor antigen
D. Prolonged bleeding time with normal platelet count and
normal coagulation studies
Rationale: DIC consumes platelets and clotting factors, producing
thrombocytopenia, prolonged PT/PTT, low fibrinogen, and elevated
D-dimer from secondary fibrinolysis. ITP causes isolated
thrombocytopenia with normal coagulation studies. The other
options describe different hemostatic disorders .
Question 3
In heart failure with reduced ejection fraction, which
compensatory mechanism ultimately worsens myocardial
workload and remodeling?
A. Increased parasympathetic vagal tone
B. Activation of the renin-angiotensin-aldosterone system
C. Upregulation of natriuretic peptides
,D. Decreased circulating catecholamines
Rationale: RAAS activation promotes vasoconstriction, sodium and
water retention, and aldosterone-mediated fibrosis, which increase
preload and afterload and drive adverse remodeling. Natriuretic
peptides are counter-regulatory, and parasympathetic tone and
reduced catecholamines would not worsen workload .
Question 4
A patient with chronic obstructive pulmonary disease has an
arterial blood gas showing pH 7.34, PaCO₂ 58 mm Hg, and HCO₃⁻
30 mEq/L. Which interpretation is most accurate?
A. Acute respiratory acidosis without compensation
B. Compensated respiratory acidosis
C. Metabolic alkalosis with respiratory compensation
D. Uncompensated metabolic acidosis
Rationale: The elevated PaCO₂ indicates respiratory acidosis. The
pH is only mildly decreased and the bicarbonate is elevated,
demonstrating renal compensation (metabolic alkalosis) that has
partially corrected the pH toward normal. In acute respiratory
acidosis without compensation, the bicarbonate would remain near
normal (24 mEq/L) .
, Question 5
During an acute asthma attack, what is the primary
pathophysiological event causing the initial expiratory wheezing?
A. Irreversible destruction of the alveolar basement membranes
B. Smooth muscle constriction, mucosal edema, and
hypersecretion of thick mucus
C. Microvascular thrombosis within the pulmonary capillary
network
D. Paradoxical collapse of the upper trachea during the inspiratory
phase
Rationale: Asthma is an IgE-mediated hypersensitivity reaction.
Exposure to an allergen triggers mast cell degranulation, releasing
histamine and leukotrienes. These mediators cause bronchospasm,
increase capillary permeability leading to mucosal edema, and
stimulate goblet cells to hypersecrete thick mucus, severely
narrowing the airway lumen .
Question 6
A patient with advanced emphysema exhibits a prominent barrel
chest. Which process directly underlies this anatomical alteration?
A. Hypertrophy of the intercostal muscles due to chronic non-
productive coughing
B. Fibrous scarring and contraction of the pleural membranes
2026/2027 | Verified Q&A +
Rationales | Chamberlain A+ Guide
Guaranteed Pass (GRADED A+)
Question 1
A patient with systemic lupus erythematosus (SLE) develops
hemolytic anemia, thrombocytopenia, and renal injury. Which
mechanism best explains this constellation of findings?
A. IgE-mediated mast cell degranulation
B. Immune complex deposition activating complement
C. Antibody-mediated cellular destruction via Fc receptors
D. T-cell mediated direct cytotoxicity
Rationale: SLE is the prototypic type III hypersensitivity disorder.
Circulating immune complexes deposit in tissues such as the kidney
and blood vessels, then activate complement, producing
inflammation and cell destruction. Type I (IgE), type II (antibody
against fixed antigens), and type IV (T-cell) mechanisms do not
explain the multisystem pattern seen in SLE .
Question 2
,Which laboratory pattern most strongly suggests disseminated
intravascular coagulation (DIC) rather than immune
thrombocytopenic purpura (ITP)?
A. Isolated thrombocytopenia with normal PT/PTT and elevated
bleeding time
B. Thrombocytopenia with prolonged PT/PTT, low fibrinogen,
and elevated D-dimer
C. Thrombocytosis with elevated von Willebrand factor antigen
D. Prolonged bleeding time with normal platelet count and
normal coagulation studies
Rationale: DIC consumes platelets and clotting factors, producing
thrombocytopenia, prolonged PT/PTT, low fibrinogen, and elevated
D-dimer from secondary fibrinolysis. ITP causes isolated
thrombocytopenia with normal coagulation studies. The other
options describe different hemostatic disorders .
Question 3
In heart failure with reduced ejection fraction, which
compensatory mechanism ultimately worsens myocardial
workload and remodeling?
A. Increased parasympathetic vagal tone
B. Activation of the renin-angiotensin-aldosterone system
C. Upregulation of natriuretic peptides
,D. Decreased circulating catecholamines
Rationale: RAAS activation promotes vasoconstriction, sodium and
water retention, and aldosterone-mediated fibrosis, which increase
preload and afterload and drive adverse remodeling. Natriuretic
peptides are counter-regulatory, and parasympathetic tone and
reduced catecholamines would not worsen workload .
Question 4
A patient with chronic obstructive pulmonary disease has an
arterial blood gas showing pH 7.34, PaCO₂ 58 mm Hg, and HCO₃⁻
30 mEq/L. Which interpretation is most accurate?
A. Acute respiratory acidosis without compensation
B. Compensated respiratory acidosis
C. Metabolic alkalosis with respiratory compensation
D. Uncompensated metabolic acidosis
Rationale: The elevated PaCO₂ indicates respiratory acidosis. The
pH is only mildly decreased and the bicarbonate is elevated,
demonstrating renal compensation (metabolic alkalosis) that has
partially corrected the pH toward normal. In acute respiratory
acidosis without compensation, the bicarbonate would remain near
normal (24 mEq/L) .
, Question 5
During an acute asthma attack, what is the primary
pathophysiological event causing the initial expiratory wheezing?
A. Irreversible destruction of the alveolar basement membranes
B. Smooth muscle constriction, mucosal edema, and
hypersecretion of thick mucus
C. Microvascular thrombosis within the pulmonary capillary
network
D. Paradoxical collapse of the upper trachea during the inspiratory
phase
Rationale: Asthma is an IgE-mediated hypersensitivity reaction.
Exposure to an allergen triggers mast cell degranulation, releasing
histamine and leukotrienes. These mediators cause bronchospasm,
increase capillary permeability leading to mucosal edema, and
stimulate goblet cells to hypersecrete thick mucus, severely
narrowing the airway lumen .
Question 6
A patient with advanced emphysema exhibits a prominent barrel
chest. Which process directly underlies this anatomical alteration?
A. Hypertrophy of the intercostal muscles due to chronic non-
productive coughing
B. Fibrous scarring and contraction of the pleural membranes
