COMSAE PHASE 1 ADVANCED INTEGRATED
PRACTICE EXAM WITH QUESTIONS AND
VERIFIED ANSWERS, PLUS DETAILED
RATIONALES/EXPERT VERIFIED FOR
GUARANTEED PASS 2026/LATEST
UPDATE/INSTANT DOWNLOAD PDF
1. A 24-year-old man presents with several months of episodic
palpitations, diaphoresis, tremulousness, and severe headaches. During
an episode, his blood pressure is 210/118 mm Hg. Plasma metanephrines
are markedly elevated. CT demonstrates a 4-cm adrenal medullary mass.
The tumor is composed of cells that contain abundant cytoplasmic
granules and stain positively for chromogranin. Which mechanism most
directly accounts for the patient's episodic hypertension?
A. Increased aldosterone-mediated sodium retention
B. Increased catecholamine synthesis and release from chromaffin cells
C. Increased renin secretion caused by renal artery compression
D. Constitutive activation of the mineralocorticoid receptor
E. Increased cortisol production from the zona fasciculata
Answer: B. Increased catecholamine synthesis and release from
chromaffin cells
Rationale: Pheochromocytoma is a catecholamine-secreting tumor of
adrenal chromaffin cells. Chromaffin cells are modified
postganglionic sympathetic neurons that release epinephrine and
norepinephrine into the circulation. Excess catecholamines cause
episodic α1-mediated vasoconstriction, producing severe hypertension,
while β1 stimulation contributes to tachycardia and palpitations.
Chromogranin positivity reflects the neuroendocrine secretory
granules within these cells. The zona glomerulosa produces
aldosterone, the zona fasciculata produces cortisol, and the zona
1
,reticularis produces adrenal androgens; therefore, the other adrenal
mechanisms do not explain this presentation.
2. A 67-year-old man with a 50-pack-year smoking history develops
progressive hoarseness and difficulty swallowing. Examination reveals
left vocal cord paralysis. CT shows a mass in the region of the left
pulmonary hilum. Which nerve is most likely being compressed?
A. Right recurrent laryngeal nerve
B. Left phrenic nerve
C. Left recurrent laryngeal nerve
D. Left vagus nerve distal to the recurrent branch
E. Hypoglossal nerve
Answer: C. Left recurrent laryngeal nerve
Rationale: The left recurrent laryngeal nerve loops under the aortic
arch near the ligamentum arteriosum before ascending in the
tracheoesophageal groove. Consequently, an enlarged left hilar or
mediastinal structure can compress this nerve and cause ipsilateral
vocal cord paralysis and hoarseness. The right recurrent laryngeal
nerve loops around the right subclavian artery and is therefore less
vulnerable to thoracic masses. The phrenic nerve supplies the
diaphragm and would produce diaphragmatic dysfunction rather than
isolated vocal cord paralysis.
3. A 19-year-old college student develops fever, headache, photophobia,
and neck stiffness. Cerebrospinal fluid demonstrates numerous
neutrophils, markedly elevated protein, and decreased glucose. Gram
stain reveals gram-negative diplococci. Which bacterial component is
primarily responsible for the severe systemic inflammatory response
associated with this organism?
2
,A. Lipoteichoic acid
B. Exotoxin A
C. Peptidoglycan cross-linking
D. Lipooligosaccharide/endotoxin
E. M protein
Answer: D. Lipooligosaccharide/endotoxin
Rationale: Neisseria meningitidis is a gram-negative diplococcus that
causes meningitis and meningococcemia. Its outer membrane contains
lipooligosaccharide, which functions similarly to lipopolysaccharide
endotoxin. Recognition of lipid A–containing endotoxin by innate
immune receptors stimulates macrophages and other cells to release
TNF, IL-1, IL-6, and other inflammatory mediators. This can produce
fever, vasodilation, capillary leakage, hypotension, disseminated
intravascular coagulation, and shock. M protein is characteristic of
Streptococcus pyogenes, whereas lipoteichoic acid is associated with
gram-positive organisms.
4. A 45-year-old woman has progressive proximal muscle weakness and
difficulty climbing stairs. Laboratory studies reveal elevated creatine
kinase. Muscle biopsy demonstrates perifascicular atrophy and
inflammatory infiltrates. She also has an erythematous rash over the
cheeks and a violaceous rash around the eyelids. Which mechanism best
explains the muscle injury?
A. Antibody-mediated destruction of postsynaptic acetylcholine
receptors
B. CD8+ T-cell destruction of individual muscle fibers
C. Immune complex deposition involving small vessels and complement
activation
D. IgE-mediated mast-cell degranulation
E. Antibody-mediated stimulation of skeletal muscle calcium channels
3
, Answer: C. Immune complex deposition involving small vessels and
complement activation
Rationale: Dermatomyositis is an inflammatory myopathy
characterized by proximal muscle weakness and characteristic
cutaneous findings such as heliotrope rash and Gottron papules. The
muscle pathology involves complement-mediated injury to small blood
vessels supplying muscle, resulting in ischemia and perifascicular
atrophy. Polymyositis differs mechanistically because CD8+ T cells
directly attack muscle fibers. Myasthenia gravis involves antibodies
against postsynaptic acetylcholine receptors or MuSK and produces
fatigable weakness without primary muscle fiber destruction.
5. A patient with severe asthma is treated with repeated doses of
albuterol. Shortly afterward, laboratory studies demonstrate a serum
potassium concentration of 2.9 mEq/L. Which mechanism best explains
this abnormality?
A. Increased urinary potassium excretion caused by aldosterone
B. Increased intracellular potassium uptake through β2-receptor
stimulation
C. Reduced distal sodium delivery
D. Direct destruction of potassium channels in the collecting duct
E. Increased gastrointestinal potassium loss
Answer: B. Increased intracellular potassium uptake through β2-
receptor stimulation
Rationale: β2-adrenergic stimulation activates Na+/K+-ATPase
activity and promotes movement of potassium from the extracellular
fluid into cells. High-dose β2 agonists such as albuterol can therefore
cause transient hypokalemia. This is a redistribution phenomenon
rather than a true depletion of total-body potassium. β2 stimulation is
4
PRACTICE EXAM WITH QUESTIONS AND
VERIFIED ANSWERS, PLUS DETAILED
RATIONALES/EXPERT VERIFIED FOR
GUARANTEED PASS 2026/LATEST
UPDATE/INSTANT DOWNLOAD PDF
1. A 24-year-old man presents with several months of episodic
palpitations, diaphoresis, tremulousness, and severe headaches. During
an episode, his blood pressure is 210/118 mm Hg. Plasma metanephrines
are markedly elevated. CT demonstrates a 4-cm adrenal medullary mass.
The tumor is composed of cells that contain abundant cytoplasmic
granules and stain positively for chromogranin. Which mechanism most
directly accounts for the patient's episodic hypertension?
A. Increased aldosterone-mediated sodium retention
B. Increased catecholamine synthesis and release from chromaffin cells
C. Increased renin secretion caused by renal artery compression
D. Constitutive activation of the mineralocorticoid receptor
E. Increased cortisol production from the zona fasciculata
Answer: B. Increased catecholamine synthesis and release from
chromaffin cells
Rationale: Pheochromocytoma is a catecholamine-secreting tumor of
adrenal chromaffin cells. Chromaffin cells are modified
postganglionic sympathetic neurons that release epinephrine and
norepinephrine into the circulation. Excess catecholamines cause
episodic α1-mediated vasoconstriction, producing severe hypertension,
while β1 stimulation contributes to tachycardia and palpitations.
Chromogranin positivity reflects the neuroendocrine secretory
granules within these cells. The zona glomerulosa produces
aldosterone, the zona fasciculata produces cortisol, and the zona
1
,reticularis produces adrenal androgens; therefore, the other adrenal
mechanisms do not explain this presentation.
2. A 67-year-old man with a 50-pack-year smoking history develops
progressive hoarseness and difficulty swallowing. Examination reveals
left vocal cord paralysis. CT shows a mass in the region of the left
pulmonary hilum. Which nerve is most likely being compressed?
A. Right recurrent laryngeal nerve
B. Left phrenic nerve
C. Left recurrent laryngeal nerve
D. Left vagus nerve distal to the recurrent branch
E. Hypoglossal nerve
Answer: C. Left recurrent laryngeal nerve
Rationale: The left recurrent laryngeal nerve loops under the aortic
arch near the ligamentum arteriosum before ascending in the
tracheoesophageal groove. Consequently, an enlarged left hilar or
mediastinal structure can compress this nerve and cause ipsilateral
vocal cord paralysis and hoarseness. The right recurrent laryngeal
nerve loops around the right subclavian artery and is therefore less
vulnerable to thoracic masses. The phrenic nerve supplies the
diaphragm and would produce diaphragmatic dysfunction rather than
isolated vocal cord paralysis.
3. A 19-year-old college student develops fever, headache, photophobia,
and neck stiffness. Cerebrospinal fluid demonstrates numerous
neutrophils, markedly elevated protein, and decreased glucose. Gram
stain reveals gram-negative diplococci. Which bacterial component is
primarily responsible for the severe systemic inflammatory response
associated with this organism?
2
,A. Lipoteichoic acid
B. Exotoxin A
C. Peptidoglycan cross-linking
D. Lipooligosaccharide/endotoxin
E. M protein
Answer: D. Lipooligosaccharide/endotoxin
Rationale: Neisseria meningitidis is a gram-negative diplococcus that
causes meningitis and meningococcemia. Its outer membrane contains
lipooligosaccharide, which functions similarly to lipopolysaccharide
endotoxin. Recognition of lipid A–containing endotoxin by innate
immune receptors stimulates macrophages and other cells to release
TNF, IL-1, IL-6, and other inflammatory mediators. This can produce
fever, vasodilation, capillary leakage, hypotension, disseminated
intravascular coagulation, and shock. M protein is characteristic of
Streptococcus pyogenes, whereas lipoteichoic acid is associated with
gram-positive organisms.
4. A 45-year-old woman has progressive proximal muscle weakness and
difficulty climbing stairs. Laboratory studies reveal elevated creatine
kinase. Muscle biopsy demonstrates perifascicular atrophy and
inflammatory infiltrates. She also has an erythematous rash over the
cheeks and a violaceous rash around the eyelids. Which mechanism best
explains the muscle injury?
A. Antibody-mediated destruction of postsynaptic acetylcholine
receptors
B. CD8+ T-cell destruction of individual muscle fibers
C. Immune complex deposition involving small vessels and complement
activation
D. IgE-mediated mast-cell degranulation
E. Antibody-mediated stimulation of skeletal muscle calcium channels
3
, Answer: C. Immune complex deposition involving small vessels and
complement activation
Rationale: Dermatomyositis is an inflammatory myopathy
characterized by proximal muscle weakness and characteristic
cutaneous findings such as heliotrope rash and Gottron papules. The
muscle pathology involves complement-mediated injury to small blood
vessels supplying muscle, resulting in ischemia and perifascicular
atrophy. Polymyositis differs mechanistically because CD8+ T cells
directly attack muscle fibers. Myasthenia gravis involves antibodies
against postsynaptic acetylcholine receptors or MuSK and produces
fatigable weakness without primary muscle fiber destruction.
5. A patient with severe asthma is treated with repeated doses of
albuterol. Shortly afterward, laboratory studies demonstrate a serum
potassium concentration of 2.9 mEq/L. Which mechanism best explains
this abnormality?
A. Increased urinary potassium excretion caused by aldosterone
B. Increased intracellular potassium uptake through β2-receptor
stimulation
C. Reduced distal sodium delivery
D. Direct destruction of potassium channels in the collecting duct
E. Increased gastrointestinal potassium loss
Answer: B. Increased intracellular potassium uptake through β2-
receptor stimulation
Rationale: β2-adrenergic stimulation activates Na+/K+-ATPase
activity and promotes movement of potassium from the extracellular
fluid into cells. High-dose β2 agonists such as albuterol can therefore
cause transient hypokalemia. This is a redistribution phenomenon
rather than a true depletion of total-body potassium. β2 stimulation is
4
