COMSAE Phase 1 Questions with Answers &
Rationales
1. A 23-year-old male presents with fever, sore throat, and tender anterior
cervical lymph nodes. A rapid strep test is positive. The most likely causative
organism is:
A. Staphylococcus aureus
B. Streptococcus pyogenes
C. Streptococcus pneumoniae
D. Corynebacterium diphtheriae
Answer: B
Rationale: Group A β-hemolytic streptococci cause strep throat; treat with
penicillin to prevent rheumatic fever.
2. The drug that inhibits dihydrofolate reductase is:
A. Sulfamethoxazole
B. Trimethoprim
C. Penicillin
D. Isoniazid
Answer: B
Rationale: Trimethoprim blocks bacterial folate reduction; combined with
sulfa for synergy.
3. During exercise, skeletal muscle arterioles dilate mainly because of:
A. Sympathetic α-adrenergic activity
B. Local metabolites
C. Parasympathetic discharge
D. Circulating epinephrine only
, Answer: B
Rationale: ↑ CO₂, K⁺, adenosine, and lactate cause local vasodilation.
4. A 6-year-old has generalized edema, frothy urine, and hypoalbuminemia.
The renal lesion most consistent is:
A. Minimal-change disease
B. Focal segmental glomerulosclerosis
C. Acute post-streptococcal GN
D. Membranous nephropathy
Answer: A
Rationale: Common in children; podocyte foot-process effacement;
responds to steroids.
5. A patient with COPD retains CO₂ chronically. His kidneys compensate by:
A. Decreasing H⁺ excretion
B. Increasing HCO₃⁻ reabsorption
C. Decreasing ammonia production
D. Increasing phosphate excretion
Answer: B
Rationale: Renal compensation retains bicarbonate to normalize pH.
6. A 70-year-old with atrial fibrillation is started on warfarin. The best
parameter to monitor is:
A. aPTT
B. INR
C. Platelet count
D. Bleeding time
Answer: B
Rationale: INR monitors extrinsic pathway (factor VII) activity.
, 7. In OPP, the sacral axis engaged during cranial flexion is:
A. Superior transverse
B. Middle transverse
C. Inferior transverse
D. Oblique
Answer: A
Rationale: Cranial flexion → sacral base posterior about superior transverse
axis.
8. The mechanism of acetaminophen toxicity is:
A. COX inhibition
B. NAPQI formation causing hepatic necrosis
C. GABA receptor inhibition
D. Dopamine blockade
Answer: B
Rationale: NAPQI binds hepatocellular proteins; treat with N-acetylcysteine.
9. The cardiac output equals:
A. HR × Stroke Volume
B. SV ÷ HR
C. (MAP − CVP) ÷ TPR
D. HR × MAP
Answer: A
Rationale: CO = HR × SV; fundamental hemodynamic equation.
10. A newborn with continuous “machine-like” murmur likely has:
A. ASD
B. VSD
Rationales
1. A 23-year-old male presents with fever, sore throat, and tender anterior
cervical lymph nodes. A rapid strep test is positive. The most likely causative
organism is:
A. Staphylococcus aureus
B. Streptococcus pyogenes
C. Streptococcus pneumoniae
D. Corynebacterium diphtheriae
Answer: B
Rationale: Group A β-hemolytic streptococci cause strep throat; treat with
penicillin to prevent rheumatic fever.
2. The drug that inhibits dihydrofolate reductase is:
A. Sulfamethoxazole
B. Trimethoprim
C. Penicillin
D. Isoniazid
Answer: B
Rationale: Trimethoprim blocks bacterial folate reduction; combined with
sulfa for synergy.
3. During exercise, skeletal muscle arterioles dilate mainly because of:
A. Sympathetic α-adrenergic activity
B. Local metabolites
C. Parasympathetic discharge
D. Circulating epinephrine only
, Answer: B
Rationale: ↑ CO₂, K⁺, adenosine, and lactate cause local vasodilation.
4. A 6-year-old has generalized edema, frothy urine, and hypoalbuminemia.
The renal lesion most consistent is:
A. Minimal-change disease
B. Focal segmental glomerulosclerosis
C. Acute post-streptococcal GN
D. Membranous nephropathy
Answer: A
Rationale: Common in children; podocyte foot-process effacement;
responds to steroids.
5. A patient with COPD retains CO₂ chronically. His kidneys compensate by:
A. Decreasing H⁺ excretion
B. Increasing HCO₃⁻ reabsorption
C. Decreasing ammonia production
D. Increasing phosphate excretion
Answer: B
Rationale: Renal compensation retains bicarbonate to normalize pH.
6. A 70-year-old with atrial fibrillation is started on warfarin. The best
parameter to monitor is:
A. aPTT
B. INR
C. Platelet count
D. Bleeding time
Answer: B
Rationale: INR monitors extrinsic pathway (factor VII) activity.
, 7. In OPP, the sacral axis engaged during cranial flexion is:
A. Superior transverse
B. Middle transverse
C. Inferior transverse
D. Oblique
Answer: A
Rationale: Cranial flexion → sacral base posterior about superior transverse
axis.
8. The mechanism of acetaminophen toxicity is:
A. COX inhibition
B. NAPQI formation causing hepatic necrosis
C. GABA receptor inhibition
D. Dopamine blockade
Answer: B
Rationale: NAPQI binds hepatocellular proteins; treat with N-acetylcysteine.
9. The cardiac output equals:
A. HR × Stroke Volume
B. SV ÷ HR
C. (MAP − CVP) ÷ TPR
D. HR × MAP
Answer: A
Rationale: CO = HR × SV; fundamental hemodynamic equation.
10. A newborn with continuous “machine-like” murmur likely has:
A. ASD
B. VSD
