COMSAE Phase 1 ASA 101 Practice Questions
with Answers & Detailed Rationales | 100
Original COMLEX Level 1 Study Questions
Question 1 – Anatomy
A 62-year-old man undergoes surgery for a thyroid mass. Following the procedure, he develops a
hoarse voice. Laryngoscopy reveals paralysis of the right vocal cord.
Which nerve was most likely injured during surgery?
A. External branch of the superior laryngeal nerve
B. Internal branch of the superior laryngeal nerve
C. Recurrent laryngeal nerve
D. Glossopharyngeal nerve
E. Hypoglossal nerve
Answer: C. Recurrent laryngeal nerve
Rationale
The recurrent laryngeal nerve supplies all intrinsic muscles of the larynx except the cricothyroid
muscle. Injury during thyroid surgery can cause:
Hoarseness
Weak voice
Vocal cord paralysis
Difficulty speaking
The recurrent laryngeal nerve runs close to the inferior thyroid artery, making it vulnerable during
thyroidectomy.
Why the other answers are incorrect
A. External branch of the superior laryngeal nerve
Innervates the cricothyroid muscle.
Injury causes difficulty reaching high-pitched sounds rather than vocal cord paralysis.
B. Internal branch of the superior laryngeal nerve
Provides sensory innervation above the vocal cords.
D. Glossopharyngeal nerve
, Supplies the posterior one-third of the tongue and pharynx.
E. Hypoglossal nerve
Controls tongue movements.
High-Yield Pearl
Recurrent laryngeal nerve = Voice
External superior laryngeal nerve = Pitch
Question 2 – Physiology
A healthy volunteer donates one unit of blood. Two days later, his plasma erythropoietin level is
elevated.
Which cells produce erythropoietin?
A. Hepatocytes
B. Juxtaglomerular cells
C. Peritubular interstitial fibroblasts of the kidney
D. Macula densa cells
E. Bone marrow stromal cells
Answer: C. Peritubular interstitial fibroblasts of the kidney
Rationale
Erythropoietin (EPO) is produced primarily by peritubular interstitial fibroblasts in the renal cortex in
response to decreased oxygen delivery.
EPO stimulates:
Erythroid progenitor cells
Increased red blood cell production
Restoration of oxygen-carrying capacity
Why the other answers are incorrect
A. Hepatocytes
Produce EPO mainly during fetal life.
B. Juxtaglomerular cells
Produce renin.
D. Macula densa
Senses sodium concentration.
E. Bone marrow stromal cells
, Support hematopoiesis but do not produce EPO.
High-Yield Pearl
Kidney hormones:
Renin → Juxtaglomerular cells
EPO → Peritubular interstitial fibroblasts
Calcitriol activation → Proximal tubule
Question 3 – Biochemistry
A child is diagnosed with pyruvate dehydrogenase complex deficiency.
Which metabolic product will accumulate most directly?
A. Lactate
B. Acetyl-CoA
C. Citrate
D. Oxaloacetate
E. Malate
Answer: A. Lactate
Rationale
Pyruvate dehydrogenase converts pyruvate into acetyl-CoA.
When this enzyme is deficient:
Pyruvate cannot enter the citric acid cycle efficiently.
Excess pyruvate is converted to lactate by lactate dehydrogenase.
Patients develop lactic acidosis and neurologic dysfunction.
Treatment often includes:
Ketogenic diet
Thiamine supplementation (if responsive)
Why the other answers are incorrect
B. Acetyl-CoA
Production is decreased, not increased.
C–E.
These citric acid cycle intermediates are not the primary accumulating metabolite.
High-Yield Pearl
, Pyruvate can become:
Lactate
Alanine
Acetyl-CoA (via pyruvate dehydrogenase)
Question 4 – Microbiology
A 7-year-old boy presents with fever, sore throat, and a sandpaper-like rash. A throat culture grows
Gram-positive cocci in chains that are β-hemolytic and bacitracin sensitive.
Which organism is responsible?
A. Staphylococcus aureus
B. Streptococcus agalactiae
C. Streptococcus pyogenes
D. Streptococcus pneumoniae
E. Enterococcus faecalis
Answer: C. Streptococcus pyogenes
Rationale
The child has scarlet fever, caused by erythrogenic toxin-producing Streptococcus pyogenes (Group A
Streptococcus).
Key features:
Fever
Pharyngitis
Sandpaper rash
Strawberry tongue
Pastia lines
Laboratory findings:
Gram-positive cocci in chains
β-hemolytic
Bacitracin sensitive
PYR positive
Why the other answers are incorrect
A. S. aureus
Gram-positive cocci in clusters.
with Answers & Detailed Rationales | 100
Original COMLEX Level 1 Study Questions
Question 1 – Anatomy
A 62-year-old man undergoes surgery for a thyroid mass. Following the procedure, he develops a
hoarse voice. Laryngoscopy reveals paralysis of the right vocal cord.
Which nerve was most likely injured during surgery?
A. External branch of the superior laryngeal nerve
B. Internal branch of the superior laryngeal nerve
C. Recurrent laryngeal nerve
D. Glossopharyngeal nerve
E. Hypoglossal nerve
Answer: C. Recurrent laryngeal nerve
Rationale
The recurrent laryngeal nerve supplies all intrinsic muscles of the larynx except the cricothyroid
muscle. Injury during thyroid surgery can cause:
Hoarseness
Weak voice
Vocal cord paralysis
Difficulty speaking
The recurrent laryngeal nerve runs close to the inferior thyroid artery, making it vulnerable during
thyroidectomy.
Why the other answers are incorrect
A. External branch of the superior laryngeal nerve
Innervates the cricothyroid muscle.
Injury causes difficulty reaching high-pitched sounds rather than vocal cord paralysis.
B. Internal branch of the superior laryngeal nerve
Provides sensory innervation above the vocal cords.
D. Glossopharyngeal nerve
, Supplies the posterior one-third of the tongue and pharynx.
E. Hypoglossal nerve
Controls tongue movements.
High-Yield Pearl
Recurrent laryngeal nerve = Voice
External superior laryngeal nerve = Pitch
Question 2 – Physiology
A healthy volunteer donates one unit of blood. Two days later, his plasma erythropoietin level is
elevated.
Which cells produce erythropoietin?
A. Hepatocytes
B. Juxtaglomerular cells
C. Peritubular interstitial fibroblasts of the kidney
D. Macula densa cells
E. Bone marrow stromal cells
Answer: C. Peritubular interstitial fibroblasts of the kidney
Rationale
Erythropoietin (EPO) is produced primarily by peritubular interstitial fibroblasts in the renal cortex in
response to decreased oxygen delivery.
EPO stimulates:
Erythroid progenitor cells
Increased red blood cell production
Restoration of oxygen-carrying capacity
Why the other answers are incorrect
A. Hepatocytes
Produce EPO mainly during fetal life.
B. Juxtaglomerular cells
Produce renin.
D. Macula densa
Senses sodium concentration.
E. Bone marrow stromal cells
, Support hematopoiesis but do not produce EPO.
High-Yield Pearl
Kidney hormones:
Renin → Juxtaglomerular cells
EPO → Peritubular interstitial fibroblasts
Calcitriol activation → Proximal tubule
Question 3 – Biochemistry
A child is diagnosed with pyruvate dehydrogenase complex deficiency.
Which metabolic product will accumulate most directly?
A. Lactate
B. Acetyl-CoA
C. Citrate
D. Oxaloacetate
E. Malate
Answer: A. Lactate
Rationale
Pyruvate dehydrogenase converts pyruvate into acetyl-CoA.
When this enzyme is deficient:
Pyruvate cannot enter the citric acid cycle efficiently.
Excess pyruvate is converted to lactate by lactate dehydrogenase.
Patients develop lactic acidosis and neurologic dysfunction.
Treatment often includes:
Ketogenic diet
Thiamine supplementation (if responsive)
Why the other answers are incorrect
B. Acetyl-CoA
Production is decreased, not increased.
C–E.
These citric acid cycle intermediates are not the primary accumulating metabolite.
High-Yield Pearl
, Pyruvate can become:
Lactate
Alanine
Acetyl-CoA (via pyruvate dehydrogenase)
Question 4 – Microbiology
A 7-year-old boy presents with fever, sore throat, and a sandpaper-like rash. A throat culture grows
Gram-positive cocci in chains that are β-hemolytic and bacitracin sensitive.
Which organism is responsible?
A. Staphylococcus aureus
B. Streptococcus agalactiae
C. Streptococcus pyogenes
D. Streptococcus pneumoniae
E. Enterococcus faecalis
Answer: C. Streptococcus pyogenes
Rationale
The child has scarlet fever, caused by erythrogenic toxin-producing Streptococcus pyogenes (Group A
Streptococcus).
Key features:
Fever
Pharyngitis
Sandpaper rash
Strawberry tongue
Pastia lines
Laboratory findings:
Gram-positive cocci in chains
β-hemolytic
Bacitracin sensitive
PYR positive
Why the other answers are incorrect
A. S. aureus
Gram-positive cocci in clusters.
