COMSAE Comprehensive Midterm
Assessment Form CMA 105 Exam Practice
Questions & [Verified Answers], Plus
Explained Rationales|2026 Latest Update|
Instant Download PDF
1. A 58-year-old man presents with progressive fatigue, paresthesias
of the feet, and gait instability. He underwent a partial
gastrectomy 10 years ago for peptic ulcer disease. Examination
reveals decreased vibratory sensation, spasticity of the lower
extremities, and a smooth beefy-red tongue. Laboratory studies
show hemoglobin 8.9 g/dL, MCV 118 fL, elevated methylmalonic
acid, and elevated homocysteine. Which of the following best
explains his neurologic findings?
A. Impaired tetrahydrofolate synthesis
B. Defective methionine synthase activity causing demyelination
C. Iron deficiency causing posterior column degeneration
D. Deficiency of pyridoxine causing axonal neuropathy
E. Autoimmune destruction of Schwann cells
Answer: B. Defective methionine synthase activity causing
demyelination
Rationale: Vitamin B12 deficiency causes subacute combined
degeneration of the spinal cord involving the dorsal columns, lateral
corticospinal tracts, and spinocerebellar tracts. Elevated
methylmalonic acid distinguishes B12 deficiency from folate
deficiency. Neurologic symptoms result from impaired methylation
reactions causing abnormal myelin formation.
, 2. A 23-year-old woman develops fever, migratory polyarthritis,
hematuria, and pleuritic chest pain. Laboratory studies reveal ANA
positivity, anti-dsDNA antibodies, and decreased C3 and C4 levels.
Which hypersensitivity reaction is primarily responsible?
A. Type I
B. Type II
C. Type III
D. Type IV
E. Type V
Answer: C. Type III
Rationale: Systemic lupus erythematosus is caused by circulating
immune complexes depositing in tissues including glomeruli, skin, and
joints. Complement activation leads to inflammation and
consumption of complement proteins.
3. A newborn develops respiratory distress shortly after birth. Chest
radiograph demonstrates diffuse ground-glass opacities with air
bronchograms. Which fetal cell type failed to mature
appropriately?
A. Type I pneumocyte
B. Type II pneumocyte
C. Clara cell
D. Alveolar macrophage
E. Endothelial cell
Answer: B. Type II pneumocyte
Rationale: Type II pneumocytes synthesize surfactant, which lowers
alveolar surface tension. Prematurity results in surfactant deficiency
leading to neonatal respiratory distress syndrome characterized by
diffuse atelectasis and ground-glass infiltrates.
, 4. A 68-year-old smoker develops hematuria. Cystoscopy reveals a
papillary bladder mass. Histology shows malignant transitional
epithelial cells. Which risk factor is most strongly associated with
this tumor?
A. Epstein-Barr virus
B. Asbestos exposure
C. Cigarette smoking
D. Human herpesvirus-8
E. Helicobacter pylori
Answer: C. Cigarette smoking
Rationale: Cigarette smoking is the most significant risk factor for
urothelial carcinoma because carcinogens are concentrated in urine,
exposing the bladder epithelium to mutagenic compounds.
5. A patient with chronic alcoholism develops confusion,
ophthalmoplegia, and ataxia. MRI shows lesions in the
mammillary bodies. Which vitamin deficiency is responsible?
A. Vitamin B1
B. Vitamin B2
C. Vitamin B6
D. Vitamin B9
E. Vitamin E
Answer: A. Vitamin B1
Rationale: Thiamine deficiency causes Wernicke encephalopathy
characterized by confusion, ophthalmoplegia, and ataxia. Mammillary
body degeneration is a classic neuropathologic finding.
6. A 30-year-old woman develops palpitations, heat intolerance, and
weight loss. Laboratory findings include low TSH and elevated T4.
, She has exophthalmos and pretibial myxedema. Which antibody is
responsible?
A. Anti-thyroglobulin
B. Anti-TPO
C. TSH receptor stimulating antibody
D. Anti-dsDNA
E. Anti-centromere
Answer: C. TSH receptor stimulating antibody
Rationale: Graves disease results from IgG antibodies stimulating the
TSH receptor, increasing thyroid hormone synthesis and gland growth.
Pretibial myxedema and ophthalmopathy are unique features.
7. A 64-year-old man experiences crushing substernal chest pain for
2 hours. ECG demonstrates ST elevations in leads II, III, and aVF.
Occlusion of which vessel is most likely?
A. LAD
B. Circumflex artery
C. Right coronary artery
D. Left main coronary artery
E. Posterior descending branch of circumflex
Answer: C. Right coronary artery
Rationale: Inferior myocardial infarction with ST elevation in II, III, and
aVF is most commonly caused by right coronary artery occlusion. The
RCA often supplies the AV node and inferior left ventricle.
8. A diabetic patient presents with fruity breath, Kussmaul
respirations, and altered mental status. Which acid-base
disturbance is expected?
Assessment Form CMA 105 Exam Practice
Questions & [Verified Answers], Plus
Explained Rationales|2026 Latest Update|
Instant Download PDF
1. A 58-year-old man presents with progressive fatigue, paresthesias
of the feet, and gait instability. He underwent a partial
gastrectomy 10 years ago for peptic ulcer disease. Examination
reveals decreased vibratory sensation, spasticity of the lower
extremities, and a smooth beefy-red tongue. Laboratory studies
show hemoglobin 8.9 g/dL, MCV 118 fL, elevated methylmalonic
acid, and elevated homocysteine. Which of the following best
explains his neurologic findings?
A. Impaired tetrahydrofolate synthesis
B. Defective methionine synthase activity causing demyelination
C. Iron deficiency causing posterior column degeneration
D. Deficiency of pyridoxine causing axonal neuropathy
E. Autoimmune destruction of Schwann cells
Answer: B. Defective methionine synthase activity causing
demyelination
Rationale: Vitamin B12 deficiency causes subacute combined
degeneration of the spinal cord involving the dorsal columns, lateral
corticospinal tracts, and spinocerebellar tracts. Elevated
methylmalonic acid distinguishes B12 deficiency from folate
deficiency. Neurologic symptoms result from impaired methylation
reactions causing abnormal myelin formation.
, 2. A 23-year-old woman develops fever, migratory polyarthritis,
hematuria, and pleuritic chest pain. Laboratory studies reveal ANA
positivity, anti-dsDNA antibodies, and decreased C3 and C4 levels.
Which hypersensitivity reaction is primarily responsible?
A. Type I
B. Type II
C. Type III
D. Type IV
E. Type V
Answer: C. Type III
Rationale: Systemic lupus erythematosus is caused by circulating
immune complexes depositing in tissues including glomeruli, skin, and
joints. Complement activation leads to inflammation and
consumption of complement proteins.
3. A newborn develops respiratory distress shortly after birth. Chest
radiograph demonstrates diffuse ground-glass opacities with air
bronchograms. Which fetal cell type failed to mature
appropriately?
A. Type I pneumocyte
B. Type II pneumocyte
C. Clara cell
D. Alveolar macrophage
E. Endothelial cell
Answer: B. Type II pneumocyte
Rationale: Type II pneumocytes synthesize surfactant, which lowers
alveolar surface tension. Prematurity results in surfactant deficiency
leading to neonatal respiratory distress syndrome characterized by
diffuse atelectasis and ground-glass infiltrates.
, 4. A 68-year-old smoker develops hematuria. Cystoscopy reveals a
papillary bladder mass. Histology shows malignant transitional
epithelial cells. Which risk factor is most strongly associated with
this tumor?
A. Epstein-Barr virus
B. Asbestos exposure
C. Cigarette smoking
D. Human herpesvirus-8
E. Helicobacter pylori
Answer: C. Cigarette smoking
Rationale: Cigarette smoking is the most significant risk factor for
urothelial carcinoma because carcinogens are concentrated in urine,
exposing the bladder epithelium to mutagenic compounds.
5. A patient with chronic alcoholism develops confusion,
ophthalmoplegia, and ataxia. MRI shows lesions in the
mammillary bodies. Which vitamin deficiency is responsible?
A. Vitamin B1
B. Vitamin B2
C. Vitamin B6
D. Vitamin B9
E. Vitamin E
Answer: A. Vitamin B1
Rationale: Thiamine deficiency causes Wernicke encephalopathy
characterized by confusion, ophthalmoplegia, and ataxia. Mammillary
body degeneration is a classic neuropathologic finding.
6. A 30-year-old woman develops palpitations, heat intolerance, and
weight loss. Laboratory findings include low TSH and elevated T4.
, She has exophthalmos and pretibial myxedema. Which antibody is
responsible?
A. Anti-thyroglobulin
B. Anti-TPO
C. TSH receptor stimulating antibody
D. Anti-dsDNA
E. Anti-centromere
Answer: C. TSH receptor stimulating antibody
Rationale: Graves disease results from IgG antibodies stimulating the
TSH receptor, increasing thyroid hormone synthesis and gland growth.
Pretibial myxedema and ophthalmopathy are unique features.
7. A 64-year-old man experiences crushing substernal chest pain for
2 hours. ECG demonstrates ST elevations in leads II, III, and aVF.
Occlusion of which vessel is most likely?
A. LAD
B. Circumflex artery
C. Right coronary artery
D. Left main coronary artery
E. Posterior descending branch of circumflex
Answer: C. Right coronary artery
Rationale: Inferior myocardial infarction with ST elevation in II, III, and
aVF is most commonly caused by right coronary artery occlusion. The
RCA often supplies the AV node and inferior left ventricle.
8. A diabetic patient presents with fruity breath, Kussmaul
respirations, and altered mental status. Which acid-base
disturbance is expected?
