A 58-year-old male with long-standing type 2 diabetes presents with worsening peripheral
neuropathy. Laboratory analysis reveals persistent hyperglycemia with elevated intracellular
sorbitol levels in peripheral nerves. Which cellular injury mechanism is most responsible for
his progressive nerve damage?
A. Mitochondrial membrane permeability transition leading to cytochrome-c release
B. Increased polyol pathway flux causing osmotic stress and reduced NADPH availability
C. Irreversible lysosomal membrane rupture causing autophagic cell death
D. Excessive ATP production resulting in increased reactive oxygen species scavenging
Correct Answer: B
Rationale:
Hyperglycemia increases glucose shunting into the polyol (sorbitol) pathway, consuming
NADPH. This reduces glutathione regeneration, amplifying oxidative stress and osmotic
injury — the hallmark of diabetic neuropathy.
QUESTION 2 – Apoptosis vs Necrosis
Which intracellular event most reliably differentiates apoptosis from necrosis?
A. ATP depletion
B. DNA laddering into nucleosomal fragments
C. Cell swelling with membrane rupture
D. Increased intracellular calcium concentration
,Correct Answer: B
Rationale:
Apoptosis produces internucleosomal DNA fragmentation creating the ladder pattern.
Necrosis causes random DNA degradation.
QUESTION 3 – Metabolic Acidosis Interpretation
ABG:
pH 7.28, PaCO₂ 29 mmHg, HCO₃⁻ 14 mEq/L
Which acid–base disorder is present?
A. Uncompensated metabolic acidosis
B. Partially compensated metabolic acidosis
C. Fully compensated metabolic acidosis
D. Respiratory alkalosis with metabolic compensation
Correct Answer: B
Rationale:
Low pH + low HCO₃⁻ = metabolic acidosis. Low PaCO₂ = respiratory compensation is
present but pH not normalized.
QUESTION 4 – Clinical Liability Trap
, An NP independently evaluates a patient with exertional chest pain and new-onset dyspnea.
The ECG is normal. What is the most legally defensible next step?
A. Initiate beta-blocker therapy
B. Reassure patient symptoms are likely anxiety related
C. Order troponin and send to emergency department
D. Schedule outpatient stress test next week
Correct Answer: C
Rationale:
Normal ECG does NOT rule out ACS. Immediate escalation minimizes malpractice
exposure.
QUESTION 5 – Inflammatory Cascade
Which cytokine plays the most significant role in sustaining systemic inflammation in
chronic autoimmune disorders?
A. IL-4
B. IL-10
C. TNF-α
D. TGF-β
Correct Answer: C