WGU D236 Pathophysiology OA Actual Exam
2026/2027 | Questions with Verified Answers |
100% Correct | Pass Guaranteed
SECTION 1: Cellular Biology & Foundations
Q1: A patient presents with severe diarrhea. Arterial blood gas reveals: pH 7.28, PaCO₂
38 mm Hg, HCO₃⁻ 16 mEq/L. What is the primary pathophysiological process?
A. Respiratory acidosis
B. Respiratory alkalosis
C. Metabolic acidosis
D. Metabolic alkalosis
Correct Answer: C
Rationale: Disease/Process: Metabolic acidosis due to bicarbonate loss.
Pathophysiological Sequence: Severe diarrhea (etiology) causes excessive loss of
bicarbonate-rich intestinal fluids (pathogenesis). This depletes the body's base buffer
(HCO₃⁻), leading to an increase in H⁺ concentration and a low pH with a correspondingly
low HCO₃⁻ (clinical manifestation/ABG finding). The normal PaCO₂ indicates the lungs
are not compensating yet. Distractor Analysis: A & B are incorrect because the primary
disturbance is metabolic (abnormal HCO₃⁻), not respiratory (PaCO₂ is normal). D is
incorrect because diarrhea causes acid gain/base loss, not alkali gain.
,Q2: A patient with chronic kidney disease develops muscle weakness and cardiac
dysrhythmias. Lab results show K⁺ 5.8 mEq/L. Which pathophysiological mechanism is
primarily responsible for the cardiac effects?
A. Hypopolarization of cell membranes
B. Depolarization blockade due to decreased resting membrane potential
C. Increased sodium-potassium pump activity
D. Hyperpolarization of cardiac cells
Correct Answer: B
Rationale: Disease/Process: Hyperkalemia-induced cardiac toxicity. Pathophysiological
Sequence: Elevated serum K⁺ (etiology) reduces the transcellular K⁺ gradient, causing
the resting membrane potential to become less negative (depolarization, pathogenesis).
This inactivates voltage-gated Na⁺ channels, impairing cardiac action-potential
formation (conduction block), leading to arrhythmias (clinical manifestation). Distractor
Analysis: A is incorrect because hypopolarization implies increased excitability, whereas
hyperkalemic depolarization leads to inexcitability. C is incorrect because pump activity
is not increased. D is incorrect because hyperpolarization would result from
hypokalemia, not hyperkalemia.
Q3: A 55-year-old smoker presents with a chronic cough and is found to have
metaplasia of the bronchial epithelium on biopsy. Which underlying cellular adaptation
explains this finding?
A. Reversible change of one differentiated cell type to another due to chronic irritation
B. Irreversible dysplastic transformation
,C. Increased cell number (hyperplasia)
D. Decreased cell size (atrophy)
Correct Answer: A
Rationale: Disease/Process: Bronchial squamous metaplasia due to smoking.
Pathophysiological Sequence: Chronic cigarette smoke (etiology) exposes bronchial
columnar epithelium to irritants and toxins, triggering a protective but abnormal
differentiation switch (pathogenesis) whereby columnar cells transform into more
resilient squamous cells (metaplasia). This is reversible if the irritant is removed
(clinical implication). Distractor Analysis: B confuses metaplasia with dysplasia, which
involves disorganized growth and is potentially premalignant. C is hyperplasia
(increased number), not change in type. D is atrophy (decreased size), irrelevant here.
Q4: A patient with extensive burns develops generalized edema. Which Starling force
alteration is the primary cause?
A. Decreased plasma oncotic pressure
B. Increased capillary hydrostatic pressure and increased capillary permeability
C. Increased interstitial oncotic pressure
D. Decreased interstitial hydrostatic pressure
Correct Answer: B
Rationale: Disease/Process: Burn-induced edema. Pathophysiological Sequence:
Thermal injury (etiology) causes massive histamine and cytokine release, leading to
arteriolar dilation and increased capillary hydrostatic pressure, while simultaneously
damaging endothelial junctions, increasing capillary permeability (pathogenesis). Fluid
, leaks into interstitium, causing edema (clinical manifestation). Distractor Analysis: A is
a later consequence (protein loss), not the primary event. C and D are secondary shifts
due to protein leakage, not the initiating force.
Q5: A diabetic patient’s wound heals slowly. Microscopy shows decreased fibroblast
proliferation and reduced collagen deposition. Which pathophysiological mechanism is
most likely?
A. Hyperglycemia-induced non-enzymatic glycation impairing growth factor signaling
B. Increased apoptosis due to hypoxia
C. Autoimmune destruction of fibroblasts
D. Excessive glucocorticoid exposure
Correct Answer: A
Rationale: Disease/Process: Diabetic wound healing defect. Pathophysiological
Sequence: Chronic hyperglycemia (etiology) promotes advanced glycation end-products
(AGEs), which cross-link extracellular matrix and impair fibroblast migration and growth
factor binding (pathogenesis), resulting in poor granulation tissue formation (clinical
manifestation). Distractor Analysis: B is plausible in ischemic wounds but not the
primary mechanism in typical diabetic ulcers. C is not a feature of diabetes. D causes
healing impairment but is not inherent to diabetes unless exogenous steroids are used.
Q6: A patient with sepsis develops progressive oliguria and a BUN:Cr ratio >20:1. Urine
osmolality is >500 mOsm/kg. Which underlying renal pathophysiology is occurring?
A. Prerenal azotemia due to renal hypoperfusion
2026/2027 | Questions with Verified Answers |
100% Correct | Pass Guaranteed
SECTION 1: Cellular Biology & Foundations
Q1: A patient presents with severe diarrhea. Arterial blood gas reveals: pH 7.28, PaCO₂
38 mm Hg, HCO₃⁻ 16 mEq/L. What is the primary pathophysiological process?
A. Respiratory acidosis
B. Respiratory alkalosis
C. Metabolic acidosis
D. Metabolic alkalosis
Correct Answer: C
Rationale: Disease/Process: Metabolic acidosis due to bicarbonate loss.
Pathophysiological Sequence: Severe diarrhea (etiology) causes excessive loss of
bicarbonate-rich intestinal fluids (pathogenesis). This depletes the body's base buffer
(HCO₃⁻), leading to an increase in H⁺ concentration and a low pH with a correspondingly
low HCO₃⁻ (clinical manifestation/ABG finding). The normal PaCO₂ indicates the lungs
are not compensating yet. Distractor Analysis: A & B are incorrect because the primary
disturbance is metabolic (abnormal HCO₃⁻), not respiratory (PaCO₂ is normal). D is
incorrect because diarrhea causes acid gain/base loss, not alkali gain.
,Q2: A patient with chronic kidney disease develops muscle weakness and cardiac
dysrhythmias. Lab results show K⁺ 5.8 mEq/L. Which pathophysiological mechanism is
primarily responsible for the cardiac effects?
A. Hypopolarization of cell membranes
B. Depolarization blockade due to decreased resting membrane potential
C. Increased sodium-potassium pump activity
D. Hyperpolarization of cardiac cells
Correct Answer: B
Rationale: Disease/Process: Hyperkalemia-induced cardiac toxicity. Pathophysiological
Sequence: Elevated serum K⁺ (etiology) reduces the transcellular K⁺ gradient, causing
the resting membrane potential to become less negative (depolarization, pathogenesis).
This inactivates voltage-gated Na⁺ channels, impairing cardiac action-potential
formation (conduction block), leading to arrhythmias (clinical manifestation). Distractor
Analysis: A is incorrect because hypopolarization implies increased excitability, whereas
hyperkalemic depolarization leads to inexcitability. C is incorrect because pump activity
is not increased. D is incorrect because hyperpolarization would result from
hypokalemia, not hyperkalemia.
Q3: A 55-year-old smoker presents with a chronic cough and is found to have
metaplasia of the bronchial epithelium on biopsy. Which underlying cellular adaptation
explains this finding?
A. Reversible change of one differentiated cell type to another due to chronic irritation
B. Irreversible dysplastic transformation
,C. Increased cell number (hyperplasia)
D. Decreased cell size (atrophy)
Correct Answer: A
Rationale: Disease/Process: Bronchial squamous metaplasia due to smoking.
Pathophysiological Sequence: Chronic cigarette smoke (etiology) exposes bronchial
columnar epithelium to irritants and toxins, triggering a protective but abnormal
differentiation switch (pathogenesis) whereby columnar cells transform into more
resilient squamous cells (metaplasia). This is reversible if the irritant is removed
(clinical implication). Distractor Analysis: B confuses metaplasia with dysplasia, which
involves disorganized growth and is potentially premalignant. C is hyperplasia
(increased number), not change in type. D is atrophy (decreased size), irrelevant here.
Q4: A patient with extensive burns develops generalized edema. Which Starling force
alteration is the primary cause?
A. Decreased plasma oncotic pressure
B. Increased capillary hydrostatic pressure and increased capillary permeability
C. Increased interstitial oncotic pressure
D. Decreased interstitial hydrostatic pressure
Correct Answer: B
Rationale: Disease/Process: Burn-induced edema. Pathophysiological Sequence:
Thermal injury (etiology) causes massive histamine and cytokine release, leading to
arteriolar dilation and increased capillary hydrostatic pressure, while simultaneously
damaging endothelial junctions, increasing capillary permeability (pathogenesis). Fluid
, leaks into interstitium, causing edema (clinical manifestation). Distractor Analysis: A is
a later consequence (protein loss), not the primary event. C and D are secondary shifts
due to protein leakage, not the initiating force.
Q5: A diabetic patient’s wound heals slowly. Microscopy shows decreased fibroblast
proliferation and reduced collagen deposition. Which pathophysiological mechanism is
most likely?
A. Hyperglycemia-induced non-enzymatic glycation impairing growth factor signaling
B. Increased apoptosis due to hypoxia
C. Autoimmune destruction of fibroblasts
D. Excessive glucocorticoid exposure
Correct Answer: A
Rationale: Disease/Process: Diabetic wound healing defect. Pathophysiological
Sequence: Chronic hyperglycemia (etiology) promotes advanced glycation end-products
(AGEs), which cross-link extracellular matrix and impair fibroblast migration and growth
factor binding (pathogenesis), resulting in poor granulation tissue formation (clinical
manifestation). Distractor Analysis: B is plausible in ischemic wounds but not the
primary mechanism in typical diabetic ulcers. C is not a feature of diabetes. D causes
healing impairment but is not inherent to diabetes unless exogenous steroids are used.
Q6: A patient with sepsis develops progressive oliguria and a BUN:Cr ratio >20:1. Urine
osmolality is >500 mOsm/kg. Which underlying renal pathophysiology is occurring?
A. Prerenal azotemia due to renal hypoperfusion
