COMSAE Phase 1 Complete Practice Exam (Forms
113–120) | 176 High-Yield Questions with Verified
Answers & Detailed Rationales (2025–2026)
1. Cardiovascular Physiology
A 65-year-old man has hypertension and left ventricular hypertrophy. Which change is
most likely to be seen in his myocardium?
A. Decreased afterload
B. Concentric hypertrophy
C. Decreased wall stress
D. Right ventricular dilation
Answer: B. Concentric hypertrophy
Rationale: Chronic pressure overload (hypertension) leads to increased afterload, causing
sarcomeres to be added in parallel → concentric hypertrophy.
2. Microbiology
A patient presents with watery diarrhea after eating undercooked poultry. Which organism
is most likely?
A. Salmonella typhi
B. Campylobacter jejuni
C. Shigella dysenteriae
D. E. Coli O157:H7
Answer: B. Campylobacter jejuni
Rationale: Campylobacter is associated with undercooked poultry and causes
inflammatory diarrhea, often with fever and abdominal pain.
3. Pharmacology
Which drug is most appropriate for treating acute anaphylaxis?
A. Diphenhydramine
,B. Epinephrine
C. Albuterol
D. Prednisone
Answer: B. Epinephrine
Rationale: Epinephrine is first-line due to α1 (vasoconstriction), β1 (cardiac stimulation),
and β2 (bronchodilation) effects.
4. Endocrinology
A patient has weight gain, moon face, and purple striae. Lab shows elevated cortisol. What
is the most likely cause?
A. Addison disease
B. Cushing syndrome
C. Hashimoto thyroiditis
D. Pheochromocytoma
Answer: B. Cushing syndrome
Rationale: Excess cortisol leads to central obesity, striae, hypertension, and glucose
intolerance.
5. Renal Physiology
Where is most sodium reabsorbed in the nephron?
A. Collecting duct
B. Distal convoluted tubule
C. Proximal convoluted tubule
D. Loop of Henle ascending limb
Answer: C. Proximal convoluted tubule
Rationale: ~65% of filtered sodium is reabsorbed in the PCT via Na⁺/K⁺ ATPase and co-
transporters.
6. Neurology
A lesion in the lateral medulla would most likely cause:
,A. Loss of vibration sense
B. Ipsilateral facial paralysis
C. Dysphagia and hoarseness
D. Contralateral hemiplegia only
Answer: C. Dysphagia and hoarseness
Rationale: Lateral medullary (Wallenberg) syndrome affects nucleus ambiguus →
swallowing and voice deficits.
7. Immunology
Which cell type is primarily responsible for antibody production?
A. T cytotoxic cells
B. B lymphocytes
C. Macrophages
D. NK cells
Answer: B. B lymphocytes
Rationale: B cells differentiate into plasma cells, which secrete antibodies.
8. Biostatistics
A study shows a p-value of 0.03. What does this mean?
A. 3% probability the null hypothesis is true
B. 97% chance results are valid
C. 3% probability results are due to chance assuming null is true
D. Study is clinically significant
Answer: C
Rationale: P-value is the probability of observing results as extreme assuming the null
hypothesis is true.
9. OMM
Which spinal level is associated with the spleen?
A. T1–T2
, B. T4–T6
C. T7–T9
D. T10–L2
Answer: C. T7–T9
Rationale: Sympathetics to spleen arise from T7–T9 levels.
10. Pathology
Which condition is associated with caseating granulomas?
A. Sarcoidosis
B. Tuberculosis
C. Rheumatoid arthritis
D. Asthma
Answer: B. Tuberculosis
Rationale: TB causes caseating granulomas due to delayed-type hypersensitivity reaction.
11. Cardiology
A patient has aortic stenosis. Which murmur is expected?
A. Holosystolic at apex
B. Crescendo-decrescendo systolic at right upper sternal border
C. Diastolic rumble
D. Continuous machinery murmur
Answer: B
Rationale: Aortic stenosis causes an ejection systolic murmur at the right upper sternal
border.
12. Microbiology
Which organism causes “rice-water” diarrhea?
A. Vibrio cholerae
B. Clostridium difficile
113–120) | 176 High-Yield Questions with Verified
Answers & Detailed Rationales (2025–2026)
1. Cardiovascular Physiology
A 65-year-old man has hypertension and left ventricular hypertrophy. Which change is
most likely to be seen in his myocardium?
A. Decreased afterload
B. Concentric hypertrophy
C. Decreased wall stress
D. Right ventricular dilation
Answer: B. Concentric hypertrophy
Rationale: Chronic pressure overload (hypertension) leads to increased afterload, causing
sarcomeres to be added in parallel → concentric hypertrophy.
2. Microbiology
A patient presents with watery diarrhea after eating undercooked poultry. Which organism
is most likely?
A. Salmonella typhi
B. Campylobacter jejuni
C. Shigella dysenteriae
D. E. Coli O157:H7
Answer: B. Campylobacter jejuni
Rationale: Campylobacter is associated with undercooked poultry and causes
inflammatory diarrhea, often with fever and abdominal pain.
3. Pharmacology
Which drug is most appropriate for treating acute anaphylaxis?
A. Diphenhydramine
,B. Epinephrine
C. Albuterol
D. Prednisone
Answer: B. Epinephrine
Rationale: Epinephrine is first-line due to α1 (vasoconstriction), β1 (cardiac stimulation),
and β2 (bronchodilation) effects.
4. Endocrinology
A patient has weight gain, moon face, and purple striae. Lab shows elevated cortisol. What
is the most likely cause?
A. Addison disease
B. Cushing syndrome
C. Hashimoto thyroiditis
D. Pheochromocytoma
Answer: B. Cushing syndrome
Rationale: Excess cortisol leads to central obesity, striae, hypertension, and glucose
intolerance.
5. Renal Physiology
Where is most sodium reabsorbed in the nephron?
A. Collecting duct
B. Distal convoluted tubule
C. Proximal convoluted tubule
D. Loop of Henle ascending limb
Answer: C. Proximal convoluted tubule
Rationale: ~65% of filtered sodium is reabsorbed in the PCT via Na⁺/K⁺ ATPase and co-
transporters.
6. Neurology
A lesion in the lateral medulla would most likely cause:
,A. Loss of vibration sense
B. Ipsilateral facial paralysis
C. Dysphagia and hoarseness
D. Contralateral hemiplegia only
Answer: C. Dysphagia and hoarseness
Rationale: Lateral medullary (Wallenberg) syndrome affects nucleus ambiguus →
swallowing and voice deficits.
7. Immunology
Which cell type is primarily responsible for antibody production?
A. T cytotoxic cells
B. B lymphocytes
C. Macrophages
D. NK cells
Answer: B. B lymphocytes
Rationale: B cells differentiate into plasma cells, which secrete antibodies.
8. Biostatistics
A study shows a p-value of 0.03. What does this mean?
A. 3% probability the null hypothesis is true
B. 97% chance results are valid
C. 3% probability results are due to chance assuming null is true
D. Study is clinically significant
Answer: C
Rationale: P-value is the probability of observing results as extreme assuming the null
hypothesis is true.
9. OMM
Which spinal level is associated with the spleen?
A. T1–T2
, B. T4–T6
C. T7–T9
D. T10–L2
Answer: C. T7–T9
Rationale: Sympathetics to spleen arise from T7–T9 levels.
10. Pathology
Which condition is associated with caseating granulomas?
A. Sarcoidosis
B. Tuberculosis
C. Rheumatoid arthritis
D. Asthma
Answer: B. Tuberculosis
Rationale: TB causes caseating granulomas due to delayed-type hypersensitivity reaction.
11. Cardiology
A patient has aortic stenosis. Which murmur is expected?
A. Holosystolic at apex
B. Crescendo-decrescendo systolic at right upper sternal border
C. Diastolic rumble
D. Continuous machinery murmur
Answer: B
Rationale: Aortic stenosis causes an ejection systolic murmur at the right upper sternal
border.
12. Microbiology
Which organism causes “rice-water” diarrhea?
A. Vibrio cholerae
B. Clostridium difficile
