MIDTERM 2 EXAM QUESTIONS AND CORRECT
ANSWERS WITH RATIONALES GRADED A+
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1. Which is the primary pathophysiologic mechanism in acute myocardial
infarction?
A. Coronary vasospasm
B. Plaque rupture → thrombus → ischemia
C. Viral infection
D. Aortic stenosis
Answer: B
Rationale: Most MIs result from atherosclerotic plaque rupture → thrombosis →
occlusion → myocardial ischemia.
2. Which arrhythmia is most commonly associated with acute MI?
A. Atrial fibrillation
B. Ventricular tachycardia/fibrillation
C. Sinus bradycardia
D. Junctional rhythm
Answer: B
Rationale: Ischemia causes electrical instability → life-threatening ventricular
arrhythmias.
3. In left-sided heart failure, which compensatory mechanism is initially
activated?
A. Decreased sympathetic tone
B. Frank-Starling mechanism (increased preload)
C. Parasympathetic activation
D. Decreased renin secretion
Answer: B
Rationale: Increased preload stretches myocardial fibers → stronger contraction to
,maintain CO.
4. Which lab marker is most specific for liver synthetic function?
A. ALT
B. AST
C. Albumin
D. Bilirubin
Answer: C
Rationale: Low albumin indicates impaired hepatic protein synthesis.
5. Which type of shock is characterized by low systemic vascular resistance
and warm extremities?
A. Hypovolemic
B. Cardiogenic
C. Obstructive
D. Distributive (septic)
Answer: D
Rationale: Vasodilation → hypotension with warm peripheries.
6. Which electrolyte imbalance is most commonly associated with chronic
kidney disease?
A. Hypokalemia
B. Hyperkalemia
C. Hypocalcemia only
D. Hypernatremia
Answer: B
Rationale: Reduced renal excretion → K⁺ retention.
7. Which type of necrosis is typical of ischemic heart tissue?
A. Coagulative
B. Liquefactive
C. Caseous
D. Fat
,Answer: A
Rationale: Ischemia preserves tissue architecture initially → coagulative necrosis.
8. Which acid-base disturbance occurs in COPD with CO₂ retention?
A. Metabolic acidosis
B. Chronic respiratory acidosis (compensated by ↑ HCO₃⁻)
C. Metabolic alkalosis
D. Respiratory alkalosis
Answer: B
Rationale: Chronic CO₂ retention → renal compensation → increased HCO₃⁻.
9. Which lab marker rises earliest after myocardial injury?
A. CK-MB
B. Troponin
C. Myoglobin
D. LDH
Answer: C
Rationale: Myoglobin rises 1–3 hours post-injury; troponins are more specific.
10. Which mechanism causes edema in nephrotic syndrome?
A. Increased hydrostatic pressure
B. Decreased oncotic pressure (protein loss)
C. Increased lymph drainage
D. Hypernatremia
Answer: B
Rationale: Proteinuria → hypoalbuminemia → fluid shifts into interstitial spaces.
11. Which lab value is most sensitive for early kidney injury?
A. BUN
B. Creatinine
C. Urine sodium
D. LDH
Answer: B
, Rationale: Creatinine rises early with decreased GFR.
12. Which electrolyte abnormality is associated with Addison’s disease?
A. Hypernatremia, hypokalemia
B. Hypokalemia only
C. Hyponatremia, hyperkalemia
D. Hypercalcemia
Answer: C
Rationale: Aldosterone deficiency → Na⁺ loss, K⁺ retention.
13. Which pathophysiologic mechanism underlies DKA?
A. Excess insulin → hypoglycemia
B. Insulin deficiency → hyperglycemia → lipolysis → ketone production →
metabolic acidosis
C. Chronic hyperglycemia → protein catabolism
D. Increased glucose uptake
Answer: B
Rationale: Insulin deficiency prevents glucose utilization → fat breakdown →
ketone accumulation.
14. Which acid-base disorder results from prolonged diarrhea?
A. Metabolic alkalosis
B. Metabolic acidosis (loss of HCO₃⁻)
C. Respiratory acidosis
D. Respiratory alkalosis
Answer: B
Rationale: Loss of bicarbonate in stool → decreased pH → acidosis.
15. Which compensatory mechanism occurs in chronic hypoxia?
A. Decreased RBC production
B. Increased erythropoietin → polycythemia
C. Hypercapnia
D. Decreased cardiac output
Answer: B