1
WGU D115 Advanced Pathophysiology
Rapid Review | 100-Question Practice
Exam | Units 2-7 Mixed Graduate MCQs
with Rationales | OA Ready 2025/2026
1. Which best explains why the β-globin Glu→Val mutation produces sickling under
deoxygenated conditions?
A. Val adds a negative charge → electrostatic repulsion
B. Val is hydrophobic → accepts a complementary pocket on an adjacent deoxy-HbS →
polymer
C. Val forms a new hydrogen bond with α-chain
D. Val increases 2,3-BPG affinity → left-shifted curve
Key: B | Rationale: Hydrophobic valine allows longitudinal polymerization of deoxy-
HbS, rigidifying the RBC.
2. A renal graft biopsy shows “muddy-brown” granular casts. The patient received NSAIDs
for gout yesterday. Which mechanism caused the cast?
A. Afferent arteriole dilatation → hyper-filtration injury
B. Efferent vasoconstriction → prerenal azotemia → ischemic ATN → sloughed tubule
cells in TAL
C. Direct tubular toxicity by NSAID metabolites
D. Crystal obstruction by uric acid
Key: B | Rationale: NSAIDs block renal prostaglandins → lose afferent vasodilatory
brake → cortical ischemia → ATN.
3. Microscopic polyangiitis is strongly associated with which auto-antibody?
A. Anti-PR3
B. Anti-MPO
C. Anti-GBM
D. Anti-CCP
Key: B | Rationale: p-ANCA (anti-myeloperoxidase) is characteristic of microscopic
polyangiitis.
, 2
4. A 30-year-old woman with RRMS has new T2 lesions on MRI. Which cytokine
predominates in her acute plaques?
A. IL-4
B. IL-10
C. IL-17
D. TGF-β
Key: C | Rationale: Th17/IL-17 drives neutrophil recruitment and blood-brain-barrier
breakdown in MS.
5. The “pink puffer” COPD phenotype is linked to which underlying pathophysiology?
A. Centrilobular emphysema with α-1-antitrypsin deficiency
B. Pan-acinar emphysema with preserved airway elastic recoil
C. Chronic bronchitis with mucous gland hyperplasia
D. Small-airway fibrosis without parenchymal destruction
Key: B | Rationale: Pan-acinar loss increases lung compliance → patient breathes at high
lung volumes to maintain flow.
6. In cardiogenic shock, which Starling curve shift best describes the ventricle?
A. Up and to the left (increased contractility)
B. Down and to the right (decreased contractility)
C. Up and to the right (increased afterload)
D. Down and to the left (volume depletion)
Key: B | Rationale: Primary pump failure flattens the curve → lower stroke volume at
any filling pressure.
7. A patient with Addisonian crisis has Na 124 mmol/L and K 6.2 mmol/L. The
hyperkalemia is primarily due to:
A. Reduced distal Na delivery →↓K secretion
B. Aldosterone deficiency →↓ENaC expression →↓K excretion
C. Metabolic acidosis → K shift out of cells
D. Increased urine flow → K loss → total-body depletion
Key: B | Rationale: Aldosterone normally up-regulates ENaC and ROMK; lack thereof
blocks K secretion.
, 3
8. Which mutation produces the “gain-of-function” in the ACTH receptor seen in primary
bilateral macronodular adrenal hyperplasia?
A. GNAS
B. MC2R (activating)
C. PRKAR1A
D. TP53
Key: B | Rationale: Activating MC2R mutations cause ACTH-independent cortisol over-
production.
9. A 2-day-old newborn has bilious vomiting and a “double-bubble” X-ray. Which
embryologic mechanism failed?
A. Recanalization of the duodenum
B. Rotation of the midgut around SMA
C. Fusion of the pancreatic buds
D. Septation of cloaca
Key: A | Rationale: Failure of duodenal recanalization → congenital duodenal atresia.
10. Which clotting factor is NOT in the intrinsic pathway yet its deficiency prolongs the
aPTT?
A. VIII
B. IX
C. XII
D. VII
Key: D | Rationale: High-dose factor VIIa can shorten aPTT in vitro; physiologic levels
do not, but severe VII deficiency (<1 %) can mildly prolong aPTT because tissue-factor
pathway feeds IX.
11. A patient with CLL develops warm-antibody autoimmune hemolysis. The antibody
isotype is:
A. IgM
B. IgG
C. IgA
D. IgE
Key: B | Rationale: Warm autoantibodies are typically IgG, detected by DAT.
WGU D115 Advanced Pathophysiology
Rapid Review | 100-Question Practice
Exam | Units 2-7 Mixed Graduate MCQs
with Rationales | OA Ready 2025/2026
1. Which best explains why the β-globin Glu→Val mutation produces sickling under
deoxygenated conditions?
A. Val adds a negative charge → electrostatic repulsion
B. Val is hydrophobic → accepts a complementary pocket on an adjacent deoxy-HbS →
polymer
C. Val forms a new hydrogen bond with α-chain
D. Val increases 2,3-BPG affinity → left-shifted curve
Key: B | Rationale: Hydrophobic valine allows longitudinal polymerization of deoxy-
HbS, rigidifying the RBC.
2. A renal graft biopsy shows “muddy-brown” granular casts. The patient received NSAIDs
for gout yesterday. Which mechanism caused the cast?
A. Afferent arteriole dilatation → hyper-filtration injury
B. Efferent vasoconstriction → prerenal azotemia → ischemic ATN → sloughed tubule
cells in TAL
C. Direct tubular toxicity by NSAID metabolites
D. Crystal obstruction by uric acid
Key: B | Rationale: NSAIDs block renal prostaglandins → lose afferent vasodilatory
brake → cortical ischemia → ATN.
3. Microscopic polyangiitis is strongly associated with which auto-antibody?
A. Anti-PR3
B. Anti-MPO
C. Anti-GBM
D. Anti-CCP
Key: B | Rationale: p-ANCA (anti-myeloperoxidase) is characteristic of microscopic
polyangiitis.
, 2
4. A 30-year-old woman with RRMS has new T2 lesions on MRI. Which cytokine
predominates in her acute plaques?
A. IL-4
B. IL-10
C. IL-17
D. TGF-β
Key: C | Rationale: Th17/IL-17 drives neutrophil recruitment and blood-brain-barrier
breakdown in MS.
5. The “pink puffer” COPD phenotype is linked to which underlying pathophysiology?
A. Centrilobular emphysema with α-1-antitrypsin deficiency
B. Pan-acinar emphysema with preserved airway elastic recoil
C. Chronic bronchitis with mucous gland hyperplasia
D. Small-airway fibrosis without parenchymal destruction
Key: B | Rationale: Pan-acinar loss increases lung compliance → patient breathes at high
lung volumes to maintain flow.
6. In cardiogenic shock, which Starling curve shift best describes the ventricle?
A. Up and to the left (increased contractility)
B. Down and to the right (decreased contractility)
C. Up and to the right (increased afterload)
D. Down and to the left (volume depletion)
Key: B | Rationale: Primary pump failure flattens the curve → lower stroke volume at
any filling pressure.
7. A patient with Addisonian crisis has Na 124 mmol/L and K 6.2 mmol/L. The
hyperkalemia is primarily due to:
A. Reduced distal Na delivery →↓K secretion
B. Aldosterone deficiency →↓ENaC expression →↓K excretion
C. Metabolic acidosis → K shift out of cells
D. Increased urine flow → K loss → total-body depletion
Key: B | Rationale: Aldosterone normally up-regulates ENaC and ROMK; lack thereof
blocks K secretion.
, 3
8. Which mutation produces the “gain-of-function” in the ACTH receptor seen in primary
bilateral macronodular adrenal hyperplasia?
A. GNAS
B. MC2R (activating)
C. PRKAR1A
D. TP53
Key: B | Rationale: Activating MC2R mutations cause ACTH-independent cortisol over-
production.
9. A 2-day-old newborn has bilious vomiting and a “double-bubble” X-ray. Which
embryologic mechanism failed?
A. Recanalization of the duodenum
B. Rotation of the midgut around SMA
C. Fusion of the pancreatic buds
D. Septation of cloaca
Key: A | Rationale: Failure of duodenal recanalization → congenital duodenal atresia.
10. Which clotting factor is NOT in the intrinsic pathway yet its deficiency prolongs the
aPTT?
A. VIII
B. IX
C. XII
D. VII
Key: D | Rationale: High-dose factor VIIa can shorten aPTT in vitro; physiologic levels
do not, but severe VII deficiency (<1 %) can mildly prolong aPTT because tissue-factor
pathway feeds IX.
11. A patient with CLL develops warm-antibody autoimmune hemolysis. The antibody
isotype is:
A. IgM
B. IgG
C. IgA
D. IgE
Key: B | Rationale: Warm autoantibodies are typically IgG, detected by DAT.
