COMSAE Phase 1 Form 110 Questions With
Correct Answers (Verified Answers) Plus
Rationales 2026 Q&A | Instant Download Pdf
1. A 45-year-old man presents with chest pain that improves when
leaning forward and worsens when lying flat. ECG shows diffuse ST
elevation. Which of the following is the most likely diagnosis?
A. Myocardial infarction
B. Pulmonary embolism
C. Acute pericarditis
D. Aortic dissection
Answer: C
The positional chest pain (better leaning forward, worse supine)
combined with diffuse ST elevation is classic for acute pericarditis. MI
typically shows localized ST elevation and elevated troponins with
regional wall motion abnormalities. PE presents with dyspnea and
tachycardia, while aortic dissection presents with tearing chest pain
radiating to the back.
, 2. A patient has weakness that worsens with activity and improves
with rest. Edrophonium test is positive. What is the most likely
diagnosis?
A. Lambert-Eaton syndrome
B. Myasthenia gravis
C. Multiple sclerosis
D. Botulism
Answer: B
Myasthenia gravis is an autoimmune disorder against acetylcholine
receptors causing fatigable weakness. Improvement with
edrophonium (an acetylcholinesterase inhibitor) supports the
diagnosis. Lambert-Eaton improves with activity, not rest.
3. Which structure is primarily responsible for producing
cerebrospinal fluid?
A. Arachnoid villi
B. Choroid plexus
C. Dura mater
D. Ependymal cells of cortex
,Answer: B
The choroid plexus in the ventricles produces CSF by filtering plasma
and secreting fluid. Arachnoid villi absorb CSF into venous circulation.
4. A 60-year-old smoker has hypercalcemia, weight loss, and a lung
mass. Which mechanism most likely explains his hypercalcemia?
A. Increased vitamin D production
B. PTHrP secretion
C. Bone metastasis only
D. Increased calcitonin
Answer: B
Squamous cell carcinoma of the lung often secretes parathyroid
hormone-related peptide (PTHrP), causing hypercalcemia of
malignancy.
5. Which enzyme is deficient in Tay-Sachs disease?
A. Hexosaminidase A
B. Glucocerebrosidase
C. Sphingomyelinase
D. Arylsulfatase A
, Answer: A
Tay-Sachs is caused by deficiency of hexosaminidase A leading to GM2
ganglioside accumulation and neurodegeneration.
6. A patient presents with fatty acid oxidation deficiency and
hypoketotic hypoglycemia. Which enzyme is most likely deficient?
A. Carnitine shuttle enzyme
B. Glycogen phosphorylase
C. Pyruvate carboxylase
D. Lactate dehydrogenase
Answer: A
Defects in carnitine transport impair fatty acid oxidation, leading to
hypoketotic hypoglycemia because the body cannot generate ketones.
7. Which heart sound is associated with mitral valve prolapse?
A. S3
B. Mid-systolic click
C. Opening snap
D. Pericardial knock
Correct Answers (Verified Answers) Plus
Rationales 2026 Q&A | Instant Download Pdf
1. A 45-year-old man presents with chest pain that improves when
leaning forward and worsens when lying flat. ECG shows diffuse ST
elevation. Which of the following is the most likely diagnosis?
A. Myocardial infarction
B. Pulmonary embolism
C. Acute pericarditis
D. Aortic dissection
Answer: C
The positional chest pain (better leaning forward, worse supine)
combined with diffuse ST elevation is classic for acute pericarditis. MI
typically shows localized ST elevation and elevated troponins with
regional wall motion abnormalities. PE presents with dyspnea and
tachycardia, while aortic dissection presents with tearing chest pain
radiating to the back.
, 2. A patient has weakness that worsens with activity and improves
with rest. Edrophonium test is positive. What is the most likely
diagnosis?
A. Lambert-Eaton syndrome
B. Myasthenia gravis
C. Multiple sclerosis
D. Botulism
Answer: B
Myasthenia gravis is an autoimmune disorder against acetylcholine
receptors causing fatigable weakness. Improvement with
edrophonium (an acetylcholinesterase inhibitor) supports the
diagnosis. Lambert-Eaton improves with activity, not rest.
3. Which structure is primarily responsible for producing
cerebrospinal fluid?
A. Arachnoid villi
B. Choroid plexus
C. Dura mater
D. Ependymal cells of cortex
,Answer: B
The choroid plexus in the ventricles produces CSF by filtering plasma
and secreting fluid. Arachnoid villi absorb CSF into venous circulation.
4. A 60-year-old smoker has hypercalcemia, weight loss, and a lung
mass. Which mechanism most likely explains his hypercalcemia?
A. Increased vitamin D production
B. PTHrP secretion
C. Bone metastasis only
D. Increased calcitonin
Answer: B
Squamous cell carcinoma of the lung often secretes parathyroid
hormone-related peptide (PTHrP), causing hypercalcemia of
malignancy.
5. Which enzyme is deficient in Tay-Sachs disease?
A. Hexosaminidase A
B. Glucocerebrosidase
C. Sphingomyelinase
D. Arylsulfatase A
, Answer: A
Tay-Sachs is caused by deficiency of hexosaminidase A leading to GM2
ganglioside accumulation and neurodegeneration.
6. A patient presents with fatty acid oxidation deficiency and
hypoketotic hypoglycemia. Which enzyme is most likely deficient?
A. Carnitine shuttle enzyme
B. Glycogen phosphorylase
C. Pyruvate carboxylase
D. Lactate dehydrogenase
Answer: A
Defects in carnitine transport impair fatty acid oxidation, leading to
hypoketotic hypoglycemia because the body cannot generate ketones.
7. Which heart sound is associated with mitral valve prolapse?
A. S3
B. Mid-systolic click
C. Opening snap
D. Pericardial knock
