COMSAE PHASE 8 CLINICAL SCIENCES
EXAM 2026 EDITION Questions with
Answers and Concise Clinical
Rationales
Question 1
A 64-year-old man presents with progressive exertional
dyspnea and orthopnea. Examination reveals bilateral
pulmonary crackles and an S3 gallop. Echocardiography
shows an ejection fraction of 30%. Which neurohormonal
mechanism most directly contributes to progressive
ventricular remodeling in this patient?
A. Increased parasympathetic activity
B. Suppression of renin release
C. Chronic sympathetic and renin-angiotensin-aldosterone
activation
D. Increased atrial natriuretic peptide secretion
Answer: C. Chronic sympathetic and renin-angiotensin-
aldosterone activation
Chronic heart failure activates the sympathetic nervous
system and RAAS, promoting vasoconstriction, sodium
retention, hypertrophy, fibrosis, and adverse ventricular
remodeling.
,Question 2
A 23-year-old woman develops sudden pleuritic chest pain
and dyspnea 5 days after undergoing knee surgery. She is
tachycardic and mildly hypoxemic. CT angiography reveals a
pulmonary embolus. Which finding is most likely present?
A. Increased pulmonary vascular resistance
B. Decreased physiologic dead space
C. Increased pulmonary perfusion to the affected region
D. Decreased alveolar ventilation with normal perfusion
Answer: A. Increased pulmonary vascular resistance
Pulmonary embolism obstructs pulmonary blood flow,
increasing pulmonary vascular resistance and creating
ventilation-perfusion mismatch with increased dead space.
Question 3
A 7-year-old boy presents with recurrent respiratory
infections, steatorrhea, and poor weight gain. Sweat chloride
testing is markedly elevated. Which cellular defect is
responsible?
A. Defective α1-antitrypsin synthesis
B. Abnormal chloride transport across epithelial membranes
C. Impaired surfactant production
D. Defective ciliary dynein
Answer: B. Abnormal chloride transport across epithelial
membranes
,CFTR dysfunction impairs chloride and bicarbonate transport,
producing dehydrated airway secretions and pancreatic duct
obstruction.
Question 4
A 58-year-old woman develops painless jaundice and weight
loss. Imaging reveals a mass in the head of the pancreas.
Which structure is most likely compressed by the tumor?
A. Splenic artery
B. Common bile duct
C. Left gastric artery
D. Inferior mesenteric vein
Answer: B. Common bile duct
The common bile duct passes through or adjacent to the
pancreatic head; tumors in this region can obstruct bile flow
and cause painless obstructive jaundice.
Question 5
A patient with chronic kidney disease develops fatigue and
pallor. Laboratory studies show hemoglobin of 8.5 g/dL with
normal mean corpuscular volume. Which mechanism best
explains the anemia?
A. Increased erythropoietin production
B. Reduced erythropoietin production
C. Increased iron absorption
D. Excessive erythrocyte destruction
, Answer: B. Reduced erythropoietin production
Diseased kidneys produce insufficient erythropoietin, causing
decreased erythrocyte production and a normocytic anemia.
Question 6
A 35-year-old woman develops fever, hypotension, diffuse
erythema, and multiorgan dysfunction during menstruation.
She uses superabsorbent tampons. Which bacterial factor is
responsible?
A. Endotoxin-mediated complement activation
B. Superantigen-mediated T-cell activation
C. IgA protease production
D. Capsule-mediated phagocytosis inhibition
Answer: B. Superantigen-mediated T-cell activation
Staphylococcus aureus toxic shock syndrome is caused by
TSST-1, a superantigen that cross-links MHC II and T-cell
receptors, causing massive cytokine release.
Question 7
A 42-year-old man has severe epigastric pain radiating to the
back. Serum lipase is markedly elevated. Which additional
finding is most likely?
A. Decreased calcium concentration
B. Increased serum troponin
EXAM 2026 EDITION Questions with
Answers and Concise Clinical
Rationales
Question 1
A 64-year-old man presents with progressive exertional
dyspnea and orthopnea. Examination reveals bilateral
pulmonary crackles and an S3 gallop. Echocardiography
shows an ejection fraction of 30%. Which neurohormonal
mechanism most directly contributes to progressive
ventricular remodeling in this patient?
A. Increased parasympathetic activity
B. Suppression of renin release
C. Chronic sympathetic and renin-angiotensin-aldosterone
activation
D. Increased atrial natriuretic peptide secretion
Answer: C. Chronic sympathetic and renin-angiotensin-
aldosterone activation
Chronic heart failure activates the sympathetic nervous
system and RAAS, promoting vasoconstriction, sodium
retention, hypertrophy, fibrosis, and adverse ventricular
remodeling.
,Question 2
A 23-year-old woman develops sudden pleuritic chest pain
and dyspnea 5 days after undergoing knee surgery. She is
tachycardic and mildly hypoxemic. CT angiography reveals a
pulmonary embolus. Which finding is most likely present?
A. Increased pulmonary vascular resistance
B. Decreased physiologic dead space
C. Increased pulmonary perfusion to the affected region
D. Decreased alveolar ventilation with normal perfusion
Answer: A. Increased pulmonary vascular resistance
Pulmonary embolism obstructs pulmonary blood flow,
increasing pulmonary vascular resistance and creating
ventilation-perfusion mismatch with increased dead space.
Question 3
A 7-year-old boy presents with recurrent respiratory
infections, steatorrhea, and poor weight gain. Sweat chloride
testing is markedly elevated. Which cellular defect is
responsible?
A. Defective α1-antitrypsin synthesis
B. Abnormal chloride transport across epithelial membranes
C. Impaired surfactant production
D. Defective ciliary dynein
Answer: B. Abnormal chloride transport across epithelial
membranes
,CFTR dysfunction impairs chloride and bicarbonate transport,
producing dehydrated airway secretions and pancreatic duct
obstruction.
Question 4
A 58-year-old woman develops painless jaundice and weight
loss. Imaging reveals a mass in the head of the pancreas.
Which structure is most likely compressed by the tumor?
A. Splenic artery
B. Common bile duct
C. Left gastric artery
D. Inferior mesenteric vein
Answer: B. Common bile duct
The common bile duct passes through or adjacent to the
pancreatic head; tumors in this region can obstruct bile flow
and cause painless obstructive jaundice.
Question 5
A patient with chronic kidney disease develops fatigue and
pallor. Laboratory studies show hemoglobin of 8.5 g/dL with
normal mean corpuscular volume. Which mechanism best
explains the anemia?
A. Increased erythropoietin production
B. Reduced erythropoietin production
C. Increased iron absorption
D. Excessive erythrocyte destruction
, Answer: B. Reduced erythropoietin production
Diseased kidneys produce insufficient erythropoietin, causing
decreased erythrocyte production and a normocytic anemia.
Question 6
A 35-year-old woman develops fever, hypotension, diffuse
erythema, and multiorgan dysfunction during menstruation.
She uses superabsorbent tampons. Which bacterial factor is
responsible?
A. Endotoxin-mediated complement activation
B. Superantigen-mediated T-cell activation
C. IgA protease production
D. Capsule-mediated phagocytosis inhibition
Answer: B. Superantigen-mediated T-cell activation
Staphylococcus aureus toxic shock syndrome is caused by
TSST-1, a superantigen that cross-links MHC II and T-cell
receptors, causing massive cytokine release.
Question 7
A 42-year-old man has severe epigastric pain radiating to the
back. Serum lipase is markedly elevated. Which additional
finding is most likely?
A. Decreased calcium concentration
B. Increased serum troponin
