COMSAE Form ASA 115
Comprehensive Osteopathic Medical
Practice Exam with Verified Questions,
Detailed Answers a 2026 editon
1. A 67-year-old man presents with resting tremor,
bradykinesia, and cogwheel rigidity. Degeneration of which
structure is most responsible for his symptoms?
A. Caudate nucleus
B. Globus pallidus
C. Substantia nigra pars compacta
D. Subthalamic nucleus
E. Red nucleus
Correct Answer: C. Substantia nigra pars compacta
Rationale: Parkinson disease results from degeneration of
dopaminergic neurons in the substantia nigra pars
compacta. Dopamine normally stimulates the direct
pathway and inhibits the indirect pathway, facilitating
movement. Loss of dopamine produces bradykinesia,
rigidity, resting tremor, and postural instability.
2. A patient develops severe chest pain radiating to the left
arm. Troponin levels are elevated. Which cellular process is
most directly responsible for irreversible myocardial injury?
,A. ATP depletion alone
B. Cellular swelling
C. Ribosomal detachment
D. Membrane damage with calcium influx
E. Glycogen depletion
Correct Answer: D. Membrane damage with calcium influx
Rationale: Irreversible cell injury occurs when membrane
integrity is lost. Calcium influx activates destructive enzymes
including phospholipases, proteases, and endonucleases,
leading to cell death. ATP depletion and swelling are
potentially reversible changes.
3. A 23-year-old woman has fatigue and pallor. Laboratory
studies reveal microcytic hypochromic anemia and low
ferritin. Which laboratory finding is most likely present?
A. Increased transferrin saturation
B. Increased serum iron
C. Increased total iron-binding capacity
D. Increased ferritin
E. Decreased transferrin
Correct Answer: C. Increased total iron-binding capacity
Rationale: Iron deficiency anemia is characterized by
decreased serum iron and ferritin with compensatory
elevation of total iron-binding capacity (TIBC) due to
increased transferrin production.
,4. A patient with nephrotic syndrome develops generalized
edema. What is the primary mechanism?
A. Increased plasma oncotic pressure
B. Decreased hydrostatic pressure
C. Decreased plasma oncotic pressure
D. Increased lymphatic drainage
E. Increased serum albumin
Correct Answer: C. Decreased plasma oncotic pressure
Rationale: Massive urinary protein loss decreases serum
albumin concentration, reducing plasma oncotic pressure.
Fluid shifts from the intravascular compartment into
interstitial tissues, causing edema.
5. A child presents with recurrent respiratory infections and
abnormal chloride transport. Which defect is responsible?
A. Defective sodium channel
B. Defective potassium channel
C. Defective chloride channel
D. Defective calcium channel
E. Defective bicarbonate transporter
Correct Answer: C. Defective chloride channel
Rationale: Cystic fibrosis results from mutations in the CFTR
gene encoding a chloride channel. Dysfunction leads to thick
secretions in the lungs, pancreas, and other organs.
, 6. A patient develops sudden vision loss in one eye.
Fundoscopy reveals a cherry-red spot on the macula. What
is the diagnosis?
A. Central retinal vein occlusion
B. Retinal detachment
C. Acute glaucoma
D. Central retinal artery occlusion
E. Macular degeneration
Correct Answer: D. Central retinal artery occlusion
Rationale: Central retinal artery occlusion classically
presents with painless monocular vision loss and a cherry-
red macula due to preservation of the choroidal circulation
beneath the fovea.
7. Which neurotransmitter is deficient in Alzheimer disease?
A. Dopamine
B. Acetylcholine
C. GABA
D. Serotonin
E. Glycine
Correct Answer: B. Acetylcholine
Rationale: Degeneration of cholinergic neurons in the
nucleus basalis of Meynert contributes to cognitive decline
in Alzheimer disease. Cholinesterase inhibitors increase
acetylcholine availability.
Comprehensive Osteopathic Medical
Practice Exam with Verified Questions,
Detailed Answers a 2026 editon
1. A 67-year-old man presents with resting tremor,
bradykinesia, and cogwheel rigidity. Degeneration of which
structure is most responsible for his symptoms?
A. Caudate nucleus
B. Globus pallidus
C. Substantia nigra pars compacta
D. Subthalamic nucleus
E. Red nucleus
Correct Answer: C. Substantia nigra pars compacta
Rationale: Parkinson disease results from degeneration of
dopaminergic neurons in the substantia nigra pars
compacta. Dopamine normally stimulates the direct
pathway and inhibits the indirect pathway, facilitating
movement. Loss of dopamine produces bradykinesia,
rigidity, resting tremor, and postural instability.
2. A patient develops severe chest pain radiating to the left
arm. Troponin levels are elevated. Which cellular process is
most directly responsible for irreversible myocardial injury?
,A. ATP depletion alone
B. Cellular swelling
C. Ribosomal detachment
D. Membrane damage with calcium influx
E. Glycogen depletion
Correct Answer: D. Membrane damage with calcium influx
Rationale: Irreversible cell injury occurs when membrane
integrity is lost. Calcium influx activates destructive enzymes
including phospholipases, proteases, and endonucleases,
leading to cell death. ATP depletion and swelling are
potentially reversible changes.
3. A 23-year-old woman has fatigue and pallor. Laboratory
studies reveal microcytic hypochromic anemia and low
ferritin. Which laboratory finding is most likely present?
A. Increased transferrin saturation
B. Increased serum iron
C. Increased total iron-binding capacity
D. Increased ferritin
E. Decreased transferrin
Correct Answer: C. Increased total iron-binding capacity
Rationale: Iron deficiency anemia is characterized by
decreased serum iron and ferritin with compensatory
elevation of total iron-binding capacity (TIBC) due to
increased transferrin production.
,4. A patient with nephrotic syndrome develops generalized
edema. What is the primary mechanism?
A. Increased plasma oncotic pressure
B. Decreased hydrostatic pressure
C. Decreased plasma oncotic pressure
D. Increased lymphatic drainage
E. Increased serum albumin
Correct Answer: C. Decreased plasma oncotic pressure
Rationale: Massive urinary protein loss decreases serum
albumin concentration, reducing plasma oncotic pressure.
Fluid shifts from the intravascular compartment into
interstitial tissues, causing edema.
5. A child presents with recurrent respiratory infections and
abnormal chloride transport. Which defect is responsible?
A. Defective sodium channel
B. Defective potassium channel
C. Defective chloride channel
D. Defective calcium channel
E. Defective bicarbonate transporter
Correct Answer: C. Defective chloride channel
Rationale: Cystic fibrosis results from mutations in the CFTR
gene encoding a chloride channel. Dysfunction leads to thick
secretions in the lungs, pancreas, and other organs.
, 6. A patient develops sudden vision loss in one eye.
Fundoscopy reveals a cherry-red spot on the macula. What
is the diagnosis?
A. Central retinal vein occlusion
B. Retinal detachment
C. Acute glaucoma
D. Central retinal artery occlusion
E. Macular degeneration
Correct Answer: D. Central retinal artery occlusion
Rationale: Central retinal artery occlusion classically
presents with painless monocular vision loss and a cherry-
red macula due to preservation of the choroidal circulation
beneath the fovea.
7. Which neurotransmitter is deficient in Alzheimer disease?
A. Dopamine
B. Acetylcholine
C. GABA
D. Serotonin
E. Glycine
Correct Answer: B. Acetylcholine
Rationale: Degeneration of cholinergic neurons in the
nucleus basalis of Meynert contributes to cognitive decline
in Alzheimer disease. Cholinesterase inhibitors increase
acetylcholine availability.
