, Question 1
Which cellular change best explains the irreversible commitment to necrosis
following prolonged ischemia?
A. Reversible swelling of the endoplasmic reticulum
B. Severe ATP depletion with mitochondrial permeability transition pore
opening
C. Transient increase in intracellular calcium
D. Activation of caspase-9 without cytochrome c release
Correct Answer: B - Severe ATP depletion with mitochondrial
permeability transition pore opening
RATIONALE
Irreversible necrosis is triggered by profound ATP depletion, which
causes failure of ion pumps and opening of the mitochondrial
permeability transition pore, leading to loss of membrane integrity.
Reversible swelling and transient calcium increases are early,
reversible events. Caspase-9 activation without cytochrome c release
is not a recognized pathway.
Question 2
A patient with sepsis develops disseminated intravascular coagulation (DIC).
Which laboratory pattern is most characteristic?
A. Elevated platelet count and shortened PT
B. Decreased D-dimer and elevated fibrinogen
C. Thrombocytopenia, prolonged PT/INR, elevated D-dimer, and low
fibrinogen
D. Isolated prolonged aPTT with normal platelets
Correct Answer: C - Thrombocytopenia, prolonged PT/INR,
elevated D-dimer, and low fibrinogen
Page 2
, RATIONALE
DIC is characterized by widespread activation of coagulation, leading
to consumption of platelets and clotting factors, resulting in
thrombocytopenia, prolonged PT/INR, elevated D-dimer from
fibrinolysis, and low fibrinogen. The other options do not reflect the
consumptive coagulopathy of DIC.
Question 3
In heart failure with reduced ejection fraction (HFrEF), which mechanism
primarily contributes to reduced cardiac output?
A. Increased afterload due to systemic vasodilation
B. Impaired myocardial contractility and reduced stroke volume
C. Enhanced Frank-Starling mechanism
D. Decreased preload from venodilation
Correct Answer: B - Impaired myocardial contractility and
reduced stroke volume
RATIONALE
HFrEF is defined by reduced ejection fraction due to impaired
contractility, leading to decreased stroke volume and cardiac output.
Compensatory mechanisms such as the Frank-Starling mechanism
may initially help but eventually fail. The other options describe
opposite or compensatory changes.
Question 4
Which acid-base disturbance is most likely in a patient with prolonged
vomiting and volume depletion?
A. Metabolic acidosis with increased anion gap
B. Metabolic alkalosis with hypokalemia and hypochloremia
C. Respiratory alkalosis with decreased PaCO2
D. Mixed metabolic acidosis and respiratory acidosis
Correct Answer: B - Metabolic alkalosis with hypokalemia and
Page 3
, hypochloremia
RATIONALE
Prolonged vomiting leads to loss of hydrogen and chloride ions,
causing hypochloremic metabolic alkalosis, often with hypokalemia
due to renal potassium wasting. The other options do not match the
typical pattern of vomiting-induced alkalosis.
Question 5
Which immunoglobulin is primarily responsible for mediating immediate
hypersensitivity reactions?
A. IgA
B. IgG
C. IgE
D. IgM
Correct Answer: C - IgE
RATIONALE
IgE binds to mast cells and basophils, triggering degranulation and
release of histamine and other mediators in immediate hypersensitivity
(Type I) reactions. IgG and IgM are involved in other hypersensitivity
types, and IgA plays a role in mucosal immunity.
Question 6
Which renal change is most indicative of acute kidney injury (AKI) due to
acute tubular necrosis (ATN)?
A. Fractional excretion of sodium (FENa) < 1%
B. Urine osmolality > 500 mOsm/kg
C. FENa > 2% with muddy brown casts
D. BUN:creatinine ratio > 20:1
Correct Answer: C - FENa > 2% with muddy brown casts
Page 4
Which cellular change best explains the irreversible commitment to necrosis
following prolonged ischemia?
A. Reversible swelling of the endoplasmic reticulum
B. Severe ATP depletion with mitochondrial permeability transition pore
opening
C. Transient increase in intracellular calcium
D. Activation of caspase-9 without cytochrome c release
Correct Answer: B - Severe ATP depletion with mitochondrial
permeability transition pore opening
RATIONALE
Irreversible necrosis is triggered by profound ATP depletion, which
causes failure of ion pumps and opening of the mitochondrial
permeability transition pore, leading to loss of membrane integrity.
Reversible swelling and transient calcium increases are early,
reversible events. Caspase-9 activation without cytochrome c release
is not a recognized pathway.
Question 2
A patient with sepsis develops disseminated intravascular coagulation (DIC).
Which laboratory pattern is most characteristic?
A. Elevated platelet count and shortened PT
B. Decreased D-dimer and elevated fibrinogen
C. Thrombocytopenia, prolonged PT/INR, elevated D-dimer, and low
fibrinogen
D. Isolated prolonged aPTT with normal platelets
Correct Answer: C - Thrombocytopenia, prolonged PT/INR,
elevated D-dimer, and low fibrinogen
Page 2
, RATIONALE
DIC is characterized by widespread activation of coagulation, leading
to consumption of platelets and clotting factors, resulting in
thrombocytopenia, prolonged PT/INR, elevated D-dimer from
fibrinolysis, and low fibrinogen. The other options do not reflect the
consumptive coagulopathy of DIC.
Question 3
In heart failure with reduced ejection fraction (HFrEF), which mechanism
primarily contributes to reduced cardiac output?
A. Increased afterload due to systemic vasodilation
B. Impaired myocardial contractility and reduced stroke volume
C. Enhanced Frank-Starling mechanism
D. Decreased preload from venodilation
Correct Answer: B - Impaired myocardial contractility and
reduced stroke volume
RATIONALE
HFrEF is defined by reduced ejection fraction due to impaired
contractility, leading to decreased stroke volume and cardiac output.
Compensatory mechanisms such as the Frank-Starling mechanism
may initially help but eventually fail. The other options describe
opposite or compensatory changes.
Question 4
Which acid-base disturbance is most likely in a patient with prolonged
vomiting and volume depletion?
A. Metabolic acidosis with increased anion gap
B. Metabolic alkalosis with hypokalemia and hypochloremia
C. Respiratory alkalosis with decreased PaCO2
D. Mixed metabolic acidosis and respiratory acidosis
Correct Answer: B - Metabolic alkalosis with hypokalemia and
Page 3
, hypochloremia
RATIONALE
Prolonged vomiting leads to loss of hydrogen and chloride ions,
causing hypochloremic metabolic alkalosis, often with hypokalemia
due to renal potassium wasting. The other options do not match the
typical pattern of vomiting-induced alkalosis.
Question 5
Which immunoglobulin is primarily responsible for mediating immediate
hypersensitivity reactions?
A. IgA
B. IgG
C. IgE
D. IgM
Correct Answer: C - IgE
RATIONALE
IgE binds to mast cells and basophils, triggering degranulation and
release of histamine and other mediators in immediate hypersensitivity
(Type I) reactions. IgG and IgM are involved in other hypersensitivity
types, and IgA plays a role in mucosal immunity.
Question 6
Which renal change is most indicative of acute kidney injury (AKI) due to
acute tubular necrosis (ATN)?
A. Fractional excretion of sodium (FENa) < 1%
B. Urine osmolality > 500 mOsm/kg
C. FENa > 2% with muddy brown casts
D. BUN:creatinine ratio > 20:1
Correct Answer: C - FENa > 2% with muddy brown casts
Page 4
