COMSAE Phase 1 – Form ASA 101 Intensive
Review: Exam-Focused Practice Questions,
Detailed Answer Keys, and Step-by-Step
Rationales (PDF)
1. A 45-year-old male presents with acute onset of sharp
chest pain radiating to the back. Physical examination
reveals a widened mediastinum on chest X-ray and a
diastolic decrescendo murmur. Which of the following is
the most likely diagnosis?
A. Myocardial infarction
B. Aortic dissection
C. Pulmonary embolism
D. Pericarditis
Rationale: The presentation of tearing chest pain radiating to
the back, combined with a widened mediastinum and an
aortic regurgitation murmur (diastolic decrescendo), is classic
for aortic dissection. Myocardial infarction typically presents
with pressure-like pain, and pulmonary embolism usually
presents with pleuritic chest pain and dyspnea.
2. Which of the following cells is primarily responsible for
the secretion of intrinsic factor in the stomach?
A. Parietal cells
,B. Chief cells
C. G cells
D. Mucous neck cells
Rationale: Parietal cells are located in the oxyntic glands of
the stomach and secrete both hydrochloric acid and intrinsic
factor, which is essential for the absorption of vitamin B12 in
the terminal ileum.
3. A patient with chronic obstructive pulmonary disease
(COPD) develops respiratory acidosis. Which of the
following is the appropriate compensatory mechanism?
A. Decreased renal bicarbonate excretion
B. Increased renal bicarbonate reabsorption
C. Increased respiratory rate
D. Decreased hydrogen ion excretion
Rationale: In chronic respiratory acidosis, the kidneys
compensate by increasing the reabsorption of bicarbonate
and increasing the excretion of hydrogen ions to normalize
the blood pH over several days.
4. Which nerve is most commonly injured in a mid-shaft
fracture of the humerus?
A. Axillary nerve
B. Musculocutaneous nerve
C. Radial nerve
D. Ulnar nerve
,Rationale: The radial nerve runs in the spiral groove along the
posterior aspect of the mid-shaft of the humerus, making it
highly susceptible to injury during fractures in this anatomical
location, often resulting in wrist drop.
5. A patient is prescribed warfarin. Which of the following
laboratory values should be monitored to ensure
therapeutic efficacy?
A. INR
B. PTT
C. Bleeding time
D. Platelet count
Rationale: Warfarin acts by inhibiting the vitamin K-
dependent clotting factors (II, VII, IX, and X). The International
Normalized Ratio (INR), derived from the Prothrombin Time
(PT), is the standardized test used to monitor warfarin
therapy.
6. Which of the following organisms is the most common
cause of community-acquired pneumonia in adults?
A. Streptococcus pneumoniae
B. Mycoplasma pneumoniae
C. Haemophilus influenzae
D. Legionella pneumophila
Rationale: Streptococcus pneumoniae remains the most
frequent etiology of community-acquired pneumonia across
, all adult age groups, characterized by sudden onset of fever,
productive cough, and lobar consolidation.
7. A patient with a history of hypertension presents with
hematuria and proteinuria. A renal biopsy shows linear
IgG deposits along the glomerular basement membrane.
What is the diagnosis?
A. IgA nephropathy
B. Membranous nephropathy
C. Goodpasture syndrome
D. Post-streptococcal glomerulonephritis
Rationale: Goodpasture syndrome is caused by anti-
glomerular basement membrane antibodies, which manifest
on immunofluorescence as linear IgG deposition along the
glomerular basement membrane.
8. Which vitamin deficiency is associated with the clinical
triad of dementia, dermatitis, and diarrhea?
A. Vitamin B1
B. Vitamin B2
C. Vitamin B3
D. Vitamin B6
Rationale: Pellagra, caused by a deficiency of niacin (vitamin
B3), presents with the classic "3 Ds": dementia, dermatitis,
and diarrhea. If untreated, it can eventually lead to death.
9. What is the primary mechanism of action of
sulfonamides?
Review: Exam-Focused Practice Questions,
Detailed Answer Keys, and Step-by-Step
Rationales (PDF)
1. A 45-year-old male presents with acute onset of sharp
chest pain radiating to the back. Physical examination
reveals a widened mediastinum on chest X-ray and a
diastolic decrescendo murmur. Which of the following is
the most likely diagnosis?
A. Myocardial infarction
B. Aortic dissection
C. Pulmonary embolism
D. Pericarditis
Rationale: The presentation of tearing chest pain radiating to
the back, combined with a widened mediastinum and an
aortic regurgitation murmur (diastolic decrescendo), is classic
for aortic dissection. Myocardial infarction typically presents
with pressure-like pain, and pulmonary embolism usually
presents with pleuritic chest pain and dyspnea.
2. Which of the following cells is primarily responsible for
the secretion of intrinsic factor in the stomach?
A. Parietal cells
,B. Chief cells
C. G cells
D. Mucous neck cells
Rationale: Parietal cells are located in the oxyntic glands of
the stomach and secrete both hydrochloric acid and intrinsic
factor, which is essential for the absorption of vitamin B12 in
the terminal ileum.
3. A patient with chronic obstructive pulmonary disease
(COPD) develops respiratory acidosis. Which of the
following is the appropriate compensatory mechanism?
A. Decreased renal bicarbonate excretion
B. Increased renal bicarbonate reabsorption
C. Increased respiratory rate
D. Decreased hydrogen ion excretion
Rationale: In chronic respiratory acidosis, the kidneys
compensate by increasing the reabsorption of bicarbonate
and increasing the excretion of hydrogen ions to normalize
the blood pH over several days.
4. Which nerve is most commonly injured in a mid-shaft
fracture of the humerus?
A. Axillary nerve
B. Musculocutaneous nerve
C. Radial nerve
D. Ulnar nerve
,Rationale: The radial nerve runs in the spiral groove along the
posterior aspect of the mid-shaft of the humerus, making it
highly susceptible to injury during fractures in this anatomical
location, often resulting in wrist drop.
5. A patient is prescribed warfarin. Which of the following
laboratory values should be monitored to ensure
therapeutic efficacy?
A. INR
B. PTT
C. Bleeding time
D. Platelet count
Rationale: Warfarin acts by inhibiting the vitamin K-
dependent clotting factors (II, VII, IX, and X). The International
Normalized Ratio (INR), derived from the Prothrombin Time
(PT), is the standardized test used to monitor warfarin
therapy.
6. Which of the following organisms is the most common
cause of community-acquired pneumonia in adults?
A. Streptococcus pneumoniae
B. Mycoplasma pneumoniae
C. Haemophilus influenzae
D. Legionella pneumophila
Rationale: Streptococcus pneumoniae remains the most
frequent etiology of community-acquired pneumonia across
, all adult age groups, characterized by sudden onset of fever,
productive cough, and lobar consolidation.
7. A patient with a history of hypertension presents with
hematuria and proteinuria. A renal biopsy shows linear
IgG deposits along the glomerular basement membrane.
What is the diagnosis?
A. IgA nephropathy
B. Membranous nephropathy
C. Goodpasture syndrome
D. Post-streptococcal glomerulonephritis
Rationale: Goodpasture syndrome is caused by anti-
glomerular basement membrane antibodies, which manifest
on immunofluorescence as linear IgG deposition along the
glomerular basement membrane.
8. Which vitamin deficiency is associated with the clinical
triad of dementia, dermatitis, and diarrhea?
A. Vitamin B1
B. Vitamin B2
C. Vitamin B3
D. Vitamin B6
Rationale: Pellagra, caused by a deficiency of niacin (vitamin
B3), presents with the classic "3 Ds": dementia, dermatitis,
and diarrhea. If untreated, it can eventually lead to death.
9. What is the primary mechanism of action of
sulfonamides?
