COMSAE Phase 1 Form 103 Questions With
Correct Answers (Verified Answers) Plus
Rationales 2026 Q&A | Instant Download Pdf
1. A 45-year-old man presents with crushing substernal chest pain
radiating to his left arm. ECG shows ST elevation in leads II, III, and
aVF. Which coronary artery is most likely occluded?
A. Left anterior descending artery
B. Left circumflex artery
C. Right coronary artery
D. Posterior descending artery
Correct answer: C
Inferior wall myocardial infarctions involving leads II, III, and aVF are
most commonly due to occlusion of the right coronary artery, which
supplies the inferior portion of the left ventricle in most individuals.
2. A 23-year-old woman presents with fatigue and pallor. Lab tests
show microcytic hypochromic anemia. Which lab finding is most
consistent with iron deficiency anemia?
, A. Increased ferritin
B. Decreased total iron-binding capacity (TIBC)
C. Increased transferrin saturation
D. Decreased ferritin
Correct answer: D
Iron deficiency anemia is characterized by depleted iron stores,
leading to decreased ferritin, increased TIBC, and decreased
transferrin saturation.
3. A patient has difficulty extending his wrist after a midshaft
humeral fracture. Which nerve is most likely injured?
A. Median nerve
B. Radial nerve
C. Ulnar nerve
D. Musculocutaneous nerve
Correct answer: B
The radial nerve travels in the radial groove of the humerus and
controls wrist extension; injury leads to wrist drop.
, 4. Which structure is primarily responsible for maintaining resting
membrane potential in neurons?
A. Sodium leak channels
B. Sodium-potassium ATPase pump
C. Voltage-gated calcium channels
D. Potassium voltage-gated channels
Correct answer: B
The Na⁺/K⁺ ATPase pump maintains electrochemical gradients by
pumping 3 Na⁺ out and 2 K⁺ into the cell.
5. A 60-year-old man with chronic smoking develops centrilobular
emphysema. Which enzyme deficiency contributes most to this
condition?
A. Alpha-1 antitrypsin deficiency
B. Cystic fibrosis transmembrane conductance regulator deficiency
C. Surfactant protein deficiency
D. Myeloperoxidase deficiency
Correct answer: A
Alpha-1 antitrypsin inhibits neutrophil elastase; deficiency leads to
lung tissue destruction and emphysema.
, 6. A child presents with fever, conjunctivitis, and a “strawberry
tongue.” Which pathogen is most likely responsible?
A. Staphylococcus aureus
B. Streptococcus pyogenes
C. Corynebacterium diphtheriae
D. Epstein-Barr virus
Correct answer: B
Streptococcus pyogenes causes scarlet fever due to erythrogenic toxin.
7. Which vitamin deficiency is associated with Wernicke-Korsakoff
syndrome?
A. Vitamin B1 (thiamine)
B. Vitamin B6 (pyridoxine)
C. Vitamin B12 (cobalamin)
D. Vitamin B3 (niacin)
Correct answer: A
Thiamine deficiency leads to Wernicke encephalopathy and Korsakoff
psychosis, especially in alcohol use disorder.
Correct Answers (Verified Answers) Plus
Rationales 2026 Q&A | Instant Download Pdf
1. A 45-year-old man presents with crushing substernal chest pain
radiating to his left arm. ECG shows ST elevation in leads II, III, and
aVF. Which coronary artery is most likely occluded?
A. Left anterior descending artery
B. Left circumflex artery
C. Right coronary artery
D. Posterior descending artery
Correct answer: C
Inferior wall myocardial infarctions involving leads II, III, and aVF are
most commonly due to occlusion of the right coronary artery, which
supplies the inferior portion of the left ventricle in most individuals.
2. A 23-year-old woman presents with fatigue and pallor. Lab tests
show microcytic hypochromic anemia. Which lab finding is most
consistent with iron deficiency anemia?
, A. Increased ferritin
B. Decreased total iron-binding capacity (TIBC)
C. Increased transferrin saturation
D. Decreased ferritin
Correct answer: D
Iron deficiency anemia is characterized by depleted iron stores,
leading to decreased ferritin, increased TIBC, and decreased
transferrin saturation.
3. A patient has difficulty extending his wrist after a midshaft
humeral fracture. Which nerve is most likely injured?
A. Median nerve
B. Radial nerve
C. Ulnar nerve
D. Musculocutaneous nerve
Correct answer: B
The radial nerve travels in the radial groove of the humerus and
controls wrist extension; injury leads to wrist drop.
, 4. Which structure is primarily responsible for maintaining resting
membrane potential in neurons?
A. Sodium leak channels
B. Sodium-potassium ATPase pump
C. Voltage-gated calcium channels
D. Potassium voltage-gated channels
Correct answer: B
The Na⁺/K⁺ ATPase pump maintains electrochemical gradients by
pumping 3 Na⁺ out and 2 K⁺ into the cell.
5. A 60-year-old man with chronic smoking develops centrilobular
emphysema. Which enzyme deficiency contributes most to this
condition?
A. Alpha-1 antitrypsin deficiency
B. Cystic fibrosis transmembrane conductance regulator deficiency
C. Surfactant protein deficiency
D. Myeloperoxidase deficiency
Correct answer: A
Alpha-1 antitrypsin inhibits neutrophil elastase; deficiency leads to
lung tissue destruction and emphysema.
, 6. A child presents with fever, conjunctivitis, and a “strawberry
tongue.” Which pathogen is most likely responsible?
A. Staphylococcus aureus
B. Streptococcus pyogenes
C. Corynebacterium diphtheriae
D. Epstein-Barr virus
Correct answer: B
Streptococcus pyogenes causes scarlet fever due to erythrogenic toxin.
7. Which vitamin deficiency is associated with Wernicke-Korsakoff
syndrome?
A. Vitamin B1 (thiamine)
B. Vitamin B6 (pyridoxine)
C. Vitamin B12 (cobalamin)
D. Vitamin B3 (niacin)
Correct answer: A
Thiamine deficiency leads to Wernicke encephalopathy and Korsakoff
psychosis, especially in alcohol use disorder.
