COMSAE Phase 1 – Form ASA 112
(Comprehensive Pre-Clinical Evaluation Pool)
(2026 Edition): Comprehensive Multiple-
Choice Questions, Answers, and Detailed
Rationales
Question 1
A 22-year-old man develops recurrent respiratory infections.
Laboratory studies reveal defective microtubule function
resulting in immotile cilia. Which structure is most likely
affected?
A. Intermediate filament
B. Actin microfilament
C. Dynein arm
D. Desmin filament
E. Keratin filament
Answer: C. Dynein arm
Dynein arms generate movement of cilia through ATP-
dependent sliding of microtubules. Defects cause primary
ciliary dyskinesia, characterized by recurrent sinopulmonary
infections, infertility, and sometimes situs inversus.
Question 2
,A researcher administers a drug that selectively blocks
conversion of angiotensin I to angiotensin II. Which
physiologic change is expected?
A. Increased aldosterone secretion
B. Increased systemic vascular resistance
C. Increased sodium retention
D. Decreased efferent arteriolar constriction
E. Increased blood pressure
Answer: D. Decreased efferent arteriolar constriction
ACE inhibition decreases angiotensin II formation. Angiotensin
II normally constricts the efferent arteriole, helping maintain
glomerular filtration pressure. Blocking this effect decreases
efferent constriction.
Question 3
A 45-year-old woman has autoimmune destruction of parietal
cells. Which deficiency is most likely?
A. Vitamin C
B. Folate
C. Iron only
D. Vitamin K
E. Vitamin B12
Answer: E. Vitamin B12
Parietal cells produce intrinsic factor, which is required for
vitamin B12 absorption in the terminal ileum. Loss of intrinsic
factor causes pernicious anemia and neurologic deficits.
,Question 4
A patient experiences sudden inability to abduct the right
eye. Which cranial nerve is damaged?
A. CN III
B. CN IV
C. CN V1
D. CN VI
E. CN VII
Answer: D. CN VI
The abducens nerve innervates the lateral rectus muscle,
responsible for eye abduction. Damage results in medial
deviation and horizontal diplopia.
Question 5
A mutation causes replacement of glutamic acid by valine in
the β-globin chain. Which disorder results?
A. Thalassemia major
B. Hereditary spherocytosis
C. G6PD deficiency
D. Aplastic anemia
E. Sickle cell disease
Answer: E. Sickle cell disease
The classic point mutation in sickle cell disease substitutes
valine for glutamic acid at position six of the β-globin chain,
, promoting hemoglobin polymerization under low oxygen
conditions.
Question 6
Which hormone is secreted by the anterior pituitary?
A. ADH
B. Oxytocin
C. ACTH
D. Vasopressin
E. None of the above
Answer: C. ACTH
Adrenocorticotropic hormone (ACTH) is produced by
corticotrophs in the anterior pituitary. ADH and oxytocin are
synthesized in the hypothalamus and released from the
posterior pituitary.
Question 7
A patient presents with hypercalcemia and elevated
parathyroid hormone levels. Which cellular activity is
stimulated?
A. Osteoblast apoptosis
B. Calcitonin release
C. Osteoclast activation via osteoblast signaling
D. Reduced renal calcium reabsorption
E. Decreased vitamin D activation
(Comprehensive Pre-Clinical Evaluation Pool)
(2026 Edition): Comprehensive Multiple-
Choice Questions, Answers, and Detailed
Rationales
Question 1
A 22-year-old man develops recurrent respiratory infections.
Laboratory studies reveal defective microtubule function
resulting in immotile cilia. Which structure is most likely
affected?
A. Intermediate filament
B. Actin microfilament
C. Dynein arm
D. Desmin filament
E. Keratin filament
Answer: C. Dynein arm
Dynein arms generate movement of cilia through ATP-
dependent sliding of microtubules. Defects cause primary
ciliary dyskinesia, characterized by recurrent sinopulmonary
infections, infertility, and sometimes situs inversus.
Question 2
,A researcher administers a drug that selectively blocks
conversion of angiotensin I to angiotensin II. Which
physiologic change is expected?
A. Increased aldosterone secretion
B. Increased systemic vascular resistance
C. Increased sodium retention
D. Decreased efferent arteriolar constriction
E. Increased blood pressure
Answer: D. Decreased efferent arteriolar constriction
ACE inhibition decreases angiotensin II formation. Angiotensin
II normally constricts the efferent arteriole, helping maintain
glomerular filtration pressure. Blocking this effect decreases
efferent constriction.
Question 3
A 45-year-old woman has autoimmune destruction of parietal
cells. Which deficiency is most likely?
A. Vitamin C
B. Folate
C. Iron only
D. Vitamin K
E. Vitamin B12
Answer: E. Vitamin B12
Parietal cells produce intrinsic factor, which is required for
vitamin B12 absorption in the terminal ileum. Loss of intrinsic
factor causes pernicious anemia and neurologic deficits.
,Question 4
A patient experiences sudden inability to abduct the right
eye. Which cranial nerve is damaged?
A. CN III
B. CN IV
C. CN V1
D. CN VI
E. CN VII
Answer: D. CN VI
The abducens nerve innervates the lateral rectus muscle,
responsible for eye abduction. Damage results in medial
deviation and horizontal diplopia.
Question 5
A mutation causes replacement of glutamic acid by valine in
the β-globin chain. Which disorder results?
A. Thalassemia major
B. Hereditary spherocytosis
C. G6PD deficiency
D. Aplastic anemia
E. Sickle cell disease
Answer: E. Sickle cell disease
The classic point mutation in sickle cell disease substitutes
valine for glutamic acid at position six of the β-globin chain,
, promoting hemoglobin polymerization under low oxygen
conditions.
Question 6
Which hormone is secreted by the anterior pituitary?
A. ADH
B. Oxytocin
C. ACTH
D. Vasopressin
E. None of the above
Answer: C. ACTH
Adrenocorticotropic hormone (ACTH) is produced by
corticotrophs in the anterior pituitary. ADH and oxytocin are
synthesized in the hypothalamus and released from the
posterior pituitary.
Question 7
A patient presents with hypercalcemia and elevated
parathyroid hormone levels. Which cellular activity is
stimulated?
A. Osteoblast apoptosis
B. Calcitonin release
C. Osteoclast activation via osteoblast signaling
D. Reduced renal calcium reabsorption
E. Decreased vitamin D activation
