COMSAE PHASE 1 FORM 114 Actual EXAM – 176
QUESTIONS AND ANSWERS | VERIFIED AND
WELL DETAILED ANSWERS | PLUS RATIONALES
| LATEST EXAM UPDATE this year STUDY GUIDE
| PRACTICE TEST
COMSAE Phase 1 is the NBOME’s self-assessment for foundational biomedical
sciences and osteopathic principles, aligned with COMLEX-USA Level 1.
Exam structure (official):
176 items, single best answer
4 blocks of 44 questions
Time: ~4 hours total (about 1 hour per block)
Content domains (approximate):
o Anatomy (including osteopathic manipulative medicine – OMM)
o Physiology
o Biochemistry / Molecular biology
o Microbiology / Immunology
o Pathology
o Pharmacology
o Behavioral sciences / Biostatistics / Epidemiology
o Osteopathic principles & OMT
Q1. A 24-year-old medical student develops sudden onset of right-sided facial
droop, inability to close the right eye, and loss of taste on the anterior
,two-thirds of the tongue after a recent viral illness. Which cranial nerve is most
likely affected in this patient?*
Answer: The facial nerve (cranial nerve VII) is most likely affected.
Explanation: CN VII controls muscles of facial expression, eyelid closure, and
taste from the anterior two-thirds of the tongue; peripheral lesions cause
ipsilateral facial weakness.
Q2. A 55-year-old man with chronic alcohol use presents with confusion, ataxia,
and ophthalmoplegia. Which vitamin deficiency is most likely responsible for
this classic clinical triad?*
Answer: Thiamine (vitamin B1) deficiency is most likely responsible.
Explanation: This triad describes Wernicke encephalopathy, caused by
thiamine deficiency in chronic alcoholism and malnutrition.
Q3. A 32-year-old woman has fatigue, pallor, and glossitis. Labs show low
hemoglobin, high MCV, and hypersegmented neutrophils. Which nutrient
deficiency is most consistent with these laboratory findings?*
Answer: Vitamin B12 or folate deficiency is most consistent.
Explanation: Macrocytic anemia with hypersegmented neutrophils suggests
impaired DNA synthesis from B12 or folate deficiency.
,Q4. A 45-year-old man with hypertension is started on a medication that
selectively blocks angiotensin II receptors. Which antihypertensive drug class
does this mechanism describe?*
Answer: This describes an angiotensin II receptor blocker (ARB).
Explanation: ARBs (e.g., losartan) selectively block AT1 receptors, reducing
vasoconstriction and aldosterone secretion.
Q5. A 28-year-old woman presents with primary amenorrhea, breast
development, but absent uterus on ultrasound. Karyotype is 46,XY. Which
diagnosis is most likely in this clinical scenario?*
Answer: Androgen insensitivity syndrome is most likely.
Explanation: 46,XY individuals with defective androgen receptors develop
female external genitalia, breast development (from aromatization), and no
uterus (due to anti-Müllerian hormone from testes).
Q6. A 60-year-old man has progressive memory loss, apraxia, and agnosia. MRI
shows diffuse cortical atrophy with enlarged ventricles. Which neurotransmitter
is most decreased in this neurodegenerative condition?*
Answer: Acetylcholine is most decreased in this condition.
Explanation: Alzheimer disease is associated with loss of cholinergic neurons
in the basal forebrain, contributing to cognitive decline.
, Q7. A 22-year-old man develops a sore throat, fever, and posterior cervical
lymphadenopathy. Peripheral smear shows atypical lymphocytes. Which virus is
most likely responsible for this syndrome?*
Answer: Epstein–Barr virus (EBV) is most likely responsible.
Explanation: EBV causes infectious mononucleosis, characterized by fever,
pharyngitis, lymphadenopathy, and atypical lymphocytes.
Q8. A 35-year-old woman has heat intolerance, weight loss, tremor, and
exophthalmos. TSH is suppressed and free T4 is elevated. Which autoantibody is
most specific for her endocrine disorder?*
Answer: Thyroid-stimulating immunoglobulin (TSI) is most specific.
Explanation: Graves disease is caused by TSI that activates TSH receptors,
leading to hyperthyroidism and orbitopathy.
Q9. A 50-year-old man with type 2 diabetes has numbness and burning pain in
his feet in a stocking distribution. Which type of nerve fiber is most commonly
affected early in this neuropathy?*
Answer: Small unmyelinated C fibers are most commonly affected early.
Explanation: Diabetic neuropathy often begins with small-fiber involvement,
causing pain, burning, and autonomic symptoms.
QUESTIONS AND ANSWERS | VERIFIED AND
WELL DETAILED ANSWERS | PLUS RATIONALES
| LATEST EXAM UPDATE this year STUDY GUIDE
| PRACTICE TEST
COMSAE Phase 1 is the NBOME’s self-assessment for foundational biomedical
sciences and osteopathic principles, aligned with COMLEX-USA Level 1.
Exam structure (official):
176 items, single best answer
4 blocks of 44 questions
Time: ~4 hours total (about 1 hour per block)
Content domains (approximate):
o Anatomy (including osteopathic manipulative medicine – OMM)
o Physiology
o Biochemistry / Molecular biology
o Microbiology / Immunology
o Pathology
o Pharmacology
o Behavioral sciences / Biostatistics / Epidemiology
o Osteopathic principles & OMT
Q1. A 24-year-old medical student develops sudden onset of right-sided facial
droop, inability to close the right eye, and loss of taste on the anterior
,two-thirds of the tongue after a recent viral illness. Which cranial nerve is most
likely affected in this patient?*
Answer: The facial nerve (cranial nerve VII) is most likely affected.
Explanation: CN VII controls muscles of facial expression, eyelid closure, and
taste from the anterior two-thirds of the tongue; peripheral lesions cause
ipsilateral facial weakness.
Q2. A 55-year-old man with chronic alcohol use presents with confusion, ataxia,
and ophthalmoplegia. Which vitamin deficiency is most likely responsible for
this classic clinical triad?*
Answer: Thiamine (vitamin B1) deficiency is most likely responsible.
Explanation: This triad describes Wernicke encephalopathy, caused by
thiamine deficiency in chronic alcoholism and malnutrition.
Q3. A 32-year-old woman has fatigue, pallor, and glossitis. Labs show low
hemoglobin, high MCV, and hypersegmented neutrophils. Which nutrient
deficiency is most consistent with these laboratory findings?*
Answer: Vitamin B12 or folate deficiency is most consistent.
Explanation: Macrocytic anemia with hypersegmented neutrophils suggests
impaired DNA synthesis from B12 or folate deficiency.
,Q4. A 45-year-old man with hypertension is started on a medication that
selectively blocks angiotensin II receptors. Which antihypertensive drug class
does this mechanism describe?*
Answer: This describes an angiotensin II receptor blocker (ARB).
Explanation: ARBs (e.g., losartan) selectively block AT1 receptors, reducing
vasoconstriction and aldosterone secretion.
Q5. A 28-year-old woman presents with primary amenorrhea, breast
development, but absent uterus on ultrasound. Karyotype is 46,XY. Which
diagnosis is most likely in this clinical scenario?*
Answer: Androgen insensitivity syndrome is most likely.
Explanation: 46,XY individuals with defective androgen receptors develop
female external genitalia, breast development (from aromatization), and no
uterus (due to anti-Müllerian hormone from testes).
Q6. A 60-year-old man has progressive memory loss, apraxia, and agnosia. MRI
shows diffuse cortical atrophy with enlarged ventricles. Which neurotransmitter
is most decreased in this neurodegenerative condition?*
Answer: Acetylcholine is most decreased in this condition.
Explanation: Alzheimer disease is associated with loss of cholinergic neurons
in the basal forebrain, contributing to cognitive decline.
, Q7. A 22-year-old man develops a sore throat, fever, and posterior cervical
lymphadenopathy. Peripheral smear shows atypical lymphocytes. Which virus is
most likely responsible for this syndrome?*
Answer: Epstein–Barr virus (EBV) is most likely responsible.
Explanation: EBV causes infectious mononucleosis, characterized by fever,
pharyngitis, lymphadenopathy, and atypical lymphocytes.
Q8. A 35-year-old woman has heat intolerance, weight loss, tremor, and
exophthalmos. TSH is suppressed and free T4 is elevated. Which autoantibody is
most specific for her endocrine disorder?*
Answer: Thyroid-stimulating immunoglobulin (TSI) is most specific.
Explanation: Graves disease is caused by TSI that activates TSH receptors,
leading to hyperthyroidism and orbitopathy.
Q9. A 50-year-old man with type 2 diabetes has numbness and burning pain in
his feet in a stocking distribution. Which type of nerve fiber is most commonly
affected early in this neuropathy?*
Answer: Small unmyelinated C fibers are most commonly affected early.
Explanation: Diabetic neuropathy often begins with small-fiber involvement,
causing pain, burning, and autonomic symptoms.
