D115 Advanced
Pathophysiology Practice
Questions with Rationales
1. Cellular Injury
A patient experiences prolonged tissue hypoxia after septic shock. Which cellular
process is most directly impaired first?
A. DNA replication
B. ATP production
C. Protein synthesis
D. Lysosomal digestion
Answer: B. ATP production
Rationale:
Hypoxia decreases oxygen availability for oxidative phosphorylation in
mitochondria, causing rapid ATP depletion. ATP failure leads to sodium-potassium
pump dysfunction, cellular swelling, and eventually necrosis.
2. Inflammation
Which mediator is primarily responsible for increased vascular permeability
during acute inflammation?
A. Histamine
B. Insulin
C. Dopamine
D. Albumin
Answer: A. Histamine
,Rationale:
Histamine released from mast cells causes vasodilation and increased capillary
permeability, producing redness, warmth, and edema.
3. Apoptosis vs. Necrosis
Which statement best describes apoptosis?
A. It always causes inflammation
B. It results from traumatic injury only
C. It is programmed cell death
D. It causes extensive tissue swelling
Answer: C. It is programmed cell death
Rationale:
Apoptosis is a controlled cellular self-destruction process that typically occurs
without inflammation. Necrosis, in contrast, involves uncontrolled injury and
inflammation.
4. Genetics
A child inherits cystic fibrosis after receiving one abnormal CFTR gene from each
parent. This pattern is:
A. X-linked dominant
B. Autosomal recessive
C. Autosomal dominant
D. Mitochondrial inheritance
Answer: B. Autosomal recessive
Rationale:
Autosomal recessive disorders require two mutated alleles for disease expression.
5. Acid–Base Balance
,A patient has:
• pH = 7.28
• HCO₃⁻ = 18 mEq/L
• PaCO₂ = 32 mmHg
This indicates:
A. Respiratory acidosis
B. Respiratory alkalosis
C. Metabolic acidosis with compensation
D. Metabolic alkalosis
Answer: C. Metabolic acidosis with compensation
Rationale:
The low pH indicates acidosis, and the low bicarbonate confirms metabolic origin.
The reduced PaCO₂ shows respiratory compensation through hyperventilation.
6. Heart Failure
Which mechanism contributes most directly to pulmonary edema in left-sided
heart failure?
A. Reduced systemic vascular resistance
B. Increased pulmonary capillary hydrostatic pressure
C. Increased oncotic pressure
D. Bronchoconstriction
Answer: B. Increased pulmonary capillary hydrostatic pressure
Rationale:
Left ventricular dysfunction causes blood to back up into pulmonary circulation,
increasing hydrostatic pressure and forcing fluid into alveoli.
7. COPD Pathophysiology
A patient with emphysema develops air trapping primarily because of:
, A. Increased alveolar elasticity
B. Bronchial smooth muscle hypertrophy only
C. Destruction of alveolar walls
D. Pulmonary embolism
Answer: C. Destruction of alveolar walls
Rationale:
Loss of elastic recoil prevents effective exhalation, causing air trapping and
hyperinflation.
8. Diabetes Mellitus
In type 2 diabetes mellitus, hyperglycemia primarily results from:
A. Absolute insulin deficiency only
B. Autoimmune beta-cell destruction
C. Insulin resistance
D. Excess glucagon deficiency
Answer: C. Insulin resistance
Rationale:
Type 2 diabetes is characterized mainly by insulin resistance with relative insulin
deficiency over time.
9. Renal Disease
Why does chronic kidney disease commonly cause metabolic acidosis?
A. Excess bicarbonate retention
B. Impaired hydrogen ion excretion
C. Increased respiratory drive
D. Excess insulin production
Answer: B. Impaired hydrogen ion excretion
Rationale:
Damaged kidneys cannot effectively excrete acids or regenerate bicarbonate.
Pathophysiology Practice
Questions with Rationales
1. Cellular Injury
A patient experiences prolonged tissue hypoxia after septic shock. Which cellular
process is most directly impaired first?
A. DNA replication
B. ATP production
C. Protein synthesis
D. Lysosomal digestion
Answer: B. ATP production
Rationale:
Hypoxia decreases oxygen availability for oxidative phosphorylation in
mitochondria, causing rapid ATP depletion. ATP failure leads to sodium-potassium
pump dysfunction, cellular swelling, and eventually necrosis.
2. Inflammation
Which mediator is primarily responsible for increased vascular permeability
during acute inflammation?
A. Histamine
B. Insulin
C. Dopamine
D. Albumin
Answer: A. Histamine
,Rationale:
Histamine released from mast cells causes vasodilation and increased capillary
permeability, producing redness, warmth, and edema.
3. Apoptosis vs. Necrosis
Which statement best describes apoptosis?
A. It always causes inflammation
B. It results from traumatic injury only
C. It is programmed cell death
D. It causes extensive tissue swelling
Answer: C. It is programmed cell death
Rationale:
Apoptosis is a controlled cellular self-destruction process that typically occurs
without inflammation. Necrosis, in contrast, involves uncontrolled injury and
inflammation.
4. Genetics
A child inherits cystic fibrosis after receiving one abnormal CFTR gene from each
parent. This pattern is:
A. X-linked dominant
B. Autosomal recessive
C. Autosomal dominant
D. Mitochondrial inheritance
Answer: B. Autosomal recessive
Rationale:
Autosomal recessive disorders require two mutated alleles for disease expression.
5. Acid–Base Balance
,A patient has:
• pH = 7.28
• HCO₃⁻ = 18 mEq/L
• PaCO₂ = 32 mmHg
This indicates:
A. Respiratory acidosis
B. Respiratory alkalosis
C. Metabolic acidosis with compensation
D. Metabolic alkalosis
Answer: C. Metabolic acidosis with compensation
Rationale:
The low pH indicates acidosis, and the low bicarbonate confirms metabolic origin.
The reduced PaCO₂ shows respiratory compensation through hyperventilation.
6. Heart Failure
Which mechanism contributes most directly to pulmonary edema in left-sided
heart failure?
A. Reduced systemic vascular resistance
B. Increased pulmonary capillary hydrostatic pressure
C. Increased oncotic pressure
D. Bronchoconstriction
Answer: B. Increased pulmonary capillary hydrostatic pressure
Rationale:
Left ventricular dysfunction causes blood to back up into pulmonary circulation,
increasing hydrostatic pressure and forcing fluid into alveoli.
7. COPD Pathophysiology
A patient with emphysema develops air trapping primarily because of:
, A. Increased alveolar elasticity
B. Bronchial smooth muscle hypertrophy only
C. Destruction of alveolar walls
D. Pulmonary embolism
Answer: C. Destruction of alveolar walls
Rationale:
Loss of elastic recoil prevents effective exhalation, causing air trapping and
hyperinflation.
8. Diabetes Mellitus
In type 2 diabetes mellitus, hyperglycemia primarily results from:
A. Absolute insulin deficiency only
B. Autoimmune beta-cell destruction
C. Insulin resistance
D. Excess glucagon deficiency
Answer: C. Insulin resistance
Rationale:
Type 2 diabetes is characterized mainly by insulin resistance with relative insulin
deficiency over time.
9. Renal Disease
Why does chronic kidney disease commonly cause metabolic acidosis?
A. Excess bicarbonate retention
B. Impaired hydrogen ion excretion
C. Increased respiratory drive
D. Excess insulin production
Answer: B. Impaired hydrogen ion excretion
Rationale:
Damaged kidneys cannot effectively excrete acids or regenerate bicarbonate.
