WGU Pathophysiology D236 Exam
ACTUAL EXAM 2026/2027 | WGU D236
Pathophysiology | Verified Q&A | Pass
Guaranteed - A+ Graded
Section 1 – Cellular Adaptation, Injury, Inflammation, Immunity (Questions 1–20)
Q1. A 45-year-old patient presents with fatigue, low-grade fever, and generalized muscle aches 10 days
after a viral upper respiratory infection. Labs show elevated erythrocyte sedimentation rate (ESR) and C-
reactive protein (CRP). Which of the following best describes the underlying pathophysiology?
A. Chronic inflammation with tissue necrosis and scarring.
B. Acute inflammation mediated by histamine and neutrophil infiltration. [CORRECT]
C. Autoimmune response targeting nuclear antigens.
D. Ischemic injury from microvascular thrombosis.
Correct Answer: B
Rationale: The correct answer describes acute inflammation, which is the normal physiological response
to infection and tissue injury. Symptoms and elevated ESR/CRP 10 days post-viral illness indicate an
ongoing acute inflammatory response, not chronic inflammation. The option about chronic
inflammation with necrosis is incorrect because no evidence of persistent tissue damage or scarring is
described in the presentation. The autoimmune option fits systemic lupus erythematosus, not a post-
viral syndrome. The ischemic option suggests clot-related injury, which is not supported by the clinical
presentation.
Q2. A patient with chronic hypertension has left ventricular wall thickening on echocardiogram. This
cellular adaptation is best described as:
A. Atrophy
B. Hyperplasia
C. Hypertrophy [CORRECT]
, D. Metaplasia
Correct Answer: C
Rationale: The correct answer is hypertrophy, which is an increase in cell size resulting in enlarged tissue
mass. The heart muscle responds to increased workload from chronic hypertension by enlarging
individual cardiomyocytes, not increasing cell number. The option describing atrophy is incorrect
because that involves decrease in cell size, the opposite of what occurs with increased workload. The
option about hyperplasia is incorrect because that refers to increased cell number, not cell size; cardiac
muscle cannot undergo hyperplasia because cardiomyocytes are terminally differentiated cells. The
metaplasia option is incorrect because that involves replacement of one mature cell type with another,
which does not occur in pressure-overloaded cardiac muscle.
Q3. A patient presents with yellowing of the sclera and skin, dark urine, and pale stools. Laboratory
studies reveal elevated direct bilirubin. The most likely underlying mechanism is:
A. Excessive red blood cell hemolysis
B. Impaired hepatocyte uptake of unconjugated bilirubin
C. Obstruction of bile flow from the liver to the duodenum [CORRECT]
D. Inherited deficiency of UDP-glucuronosyltransferase enzyme
Correct Answer: C
Rationale: The correct answer describes obstructive jaundice, where blockage of bile flow prevents
bilirubin excretion into the intestine, causing conjugated bilirubin to back up into blood. Dark urine
reflects water-soluble conjugated bilirubin being excreted by kidneys, while pale stools result from
absence of bilirubin in the intestinal tract. The hemolysis option is incorrect because that causes
unconjugated hyperbilirubinemia without dark urine or pale stools. The impaired hepatocyte uptake
option describes Gilbert syndrome, which causes mild unconjugated jaundice without cholestatic
symptoms. The inherited enzyme deficiency option describes Crigler-Najjar syndrome, which also
produces unconjugated hyperbilirubinemia without the characteristic urinary and stool changes of
obstruction.
Q4. A 62-year-old smoker is found to have squamous cell carcinoma of the lung. Biopsy reveals normal
columnar epithelium replaced by stratified squamous epithelium in the bronchial lining. This change
represents:
A. Dysplasia
B. Metaplasia [CORRECT]
, C. Anaplasia
D. Hypertrophy
Correct Answer: B
Rationale: The correct answer is metaplasia, which is the reversible replacement of one differentiated
cell type with another that can better withstand a particular stressor. Chronic smoking irritation causes
bronchial columnar epithelium to transform into squamous epithelium as a protective adaptation. The
dysplasia option is incorrect because that describes disordered, pre-neoplastic cellular growth with
nuclear atypia, not a complete cell type change. The anaplasia option is incorrect because that refers to
loss of cellular differentiation characteristic of malignant tumors, not an adaptive change. The
hypertrophy option is incorrect because that involves enlargement of existing cells, not replacement
with a different cell type.
Q5. A patient with severe sepsis develops multiple organ dysfunction. Laboratory studies show elevated
lactate and metabolic acidosis. The cellular mechanism primarily responsible for organ failure is:
A. Apoptosis triggered by caspase activation
B. ATP depletion and cellular swelling from impaired oxidative phosphorylation [CORRECT]
C. Programmed cell death from tumor necrosis factor signaling
D. Lysosomal enzyme release causing autodigestion
Correct Answer: B
Rationale: The correct answer describes the core mechanism of septic shock-induced cellular injury,
where inadequate tissue perfusion and mitochondrial dysfunction lead to anaerobic metabolism, ATP
depletion, ion pump failure, and cellular swelling. The apoptosis option is incorrect because although
apoptosis occurs in sepsis, the acute organ dysfunction in severe sepsis is primarily from reversible
cellular injury due to energy failure, not programmed cell death. The programmed cell death from TNF
option is incorrect because while inflammatory cytokines contribute to sepsis pathophysiology, the
immediate organ failure stems from metabolic crisis, not TNF-mediated apoptosis. The lysosomal
enzyme option describes autophagy or autolysis, which occurs in late irreversible injury, not the primary
mechanism of acute sepsis-induced organ dysfunction.
Q6. A patient with systemic lupus erythematosus has a positive antinuclear antibody (ANA) test with
anti-double-stranded DNA specificity. The pathophysiology of this autoimmune disease involves:
A. Type I hypersensitivity mediated by IgE and mast cell degranulation
B. Type II hypersensitivity with antibody-mediated cytotoxicity
, C. Type III hypersensitivity from immune complex deposition [CORRECT]
D. Type IV hypersensitivity with T-cell mediated delayed response
Correct Answer: C
Rationale: The correct answer describes type III hypersensitivity, where autoantibodies form immune
complexes with nuclear antigens that deposit in tissues, activate complement, and cause inflammation
in kidneys, skin, and joints. The type I option is incorrect because that describes allergic reactions like
anaphylaxis and asthma, not SLE. The type II option is incorrect because although some SLE
manifestations involve antibody-mediated cytotoxicity, the primary mechanism is immune complex
deposition, not direct cell surface antibody attack. The type IV option is incorrect because that describes
T-cell mediated reactions like contact dermatitis and tuberculin response, not the autoantibody-driven
pathophysiology of lupus.
Q7. A patient develops anaphylaxis after eating shellfish. Within minutes, the patient experiences
hypotension, bronchospasm, and urticaria. The initial mediator released from mast cells is:
A. Interleukin-2
B. Histamine [CORRECT]
C. Tumor necrosis factor-alpha
D. Interferon-gamma
Correct Answer: B
Rationale: The correct answer is histamine, which is the primary preformed mediator released from
mast cell granules during IgE-mediated degranulation, causing vasodilation, increased vascular
permeability, bronchial smooth muscle contraction, and pruritus. The interleukin-2 option is incorrect
because that is a T-cell growth factor produced during adaptive immune responses, not an immediate
hypersensitivity mediator. The TNF-alpha option is incorrect because although it is produced in late-
phase reactions, it is not the initial rapid-release mediator responsible for acute anaphylaxis symptoms.
The interferon-gamma option is incorrect because that is a Th1 cytokine involved in macrophage
activation and intracellular pathogen defense, not allergic degranulation.
Q8. A patient with HIV infection has a CD4 count of 180 cells/mm³. The patient develops Pneumocystis
jirovecii pneumonia. This opportunistic infection occurs because:
A. B-lymphocyte antibody production is completely absent
B. Macrophage phagocytic function is selectively impaired
C. Helper T-cell mediated immunity is severely compromised [CORRECT]
ACTUAL EXAM 2026/2027 | WGU D236
Pathophysiology | Verified Q&A | Pass
Guaranteed - A+ Graded
Section 1 – Cellular Adaptation, Injury, Inflammation, Immunity (Questions 1–20)
Q1. A 45-year-old patient presents with fatigue, low-grade fever, and generalized muscle aches 10 days
after a viral upper respiratory infection. Labs show elevated erythrocyte sedimentation rate (ESR) and C-
reactive protein (CRP). Which of the following best describes the underlying pathophysiology?
A. Chronic inflammation with tissue necrosis and scarring.
B. Acute inflammation mediated by histamine and neutrophil infiltration. [CORRECT]
C. Autoimmune response targeting nuclear antigens.
D. Ischemic injury from microvascular thrombosis.
Correct Answer: B
Rationale: The correct answer describes acute inflammation, which is the normal physiological response
to infection and tissue injury. Symptoms and elevated ESR/CRP 10 days post-viral illness indicate an
ongoing acute inflammatory response, not chronic inflammation. The option about chronic
inflammation with necrosis is incorrect because no evidence of persistent tissue damage or scarring is
described in the presentation. The autoimmune option fits systemic lupus erythematosus, not a post-
viral syndrome. The ischemic option suggests clot-related injury, which is not supported by the clinical
presentation.
Q2. A patient with chronic hypertension has left ventricular wall thickening on echocardiogram. This
cellular adaptation is best described as:
A. Atrophy
B. Hyperplasia
C. Hypertrophy [CORRECT]
, D. Metaplasia
Correct Answer: C
Rationale: The correct answer is hypertrophy, which is an increase in cell size resulting in enlarged tissue
mass. The heart muscle responds to increased workload from chronic hypertension by enlarging
individual cardiomyocytes, not increasing cell number. The option describing atrophy is incorrect
because that involves decrease in cell size, the opposite of what occurs with increased workload. The
option about hyperplasia is incorrect because that refers to increased cell number, not cell size; cardiac
muscle cannot undergo hyperplasia because cardiomyocytes are terminally differentiated cells. The
metaplasia option is incorrect because that involves replacement of one mature cell type with another,
which does not occur in pressure-overloaded cardiac muscle.
Q3. A patient presents with yellowing of the sclera and skin, dark urine, and pale stools. Laboratory
studies reveal elevated direct bilirubin. The most likely underlying mechanism is:
A. Excessive red blood cell hemolysis
B. Impaired hepatocyte uptake of unconjugated bilirubin
C. Obstruction of bile flow from the liver to the duodenum [CORRECT]
D. Inherited deficiency of UDP-glucuronosyltransferase enzyme
Correct Answer: C
Rationale: The correct answer describes obstructive jaundice, where blockage of bile flow prevents
bilirubin excretion into the intestine, causing conjugated bilirubin to back up into blood. Dark urine
reflects water-soluble conjugated bilirubin being excreted by kidneys, while pale stools result from
absence of bilirubin in the intestinal tract. The hemolysis option is incorrect because that causes
unconjugated hyperbilirubinemia without dark urine or pale stools. The impaired hepatocyte uptake
option describes Gilbert syndrome, which causes mild unconjugated jaundice without cholestatic
symptoms. The inherited enzyme deficiency option describes Crigler-Najjar syndrome, which also
produces unconjugated hyperbilirubinemia without the characteristic urinary and stool changes of
obstruction.
Q4. A 62-year-old smoker is found to have squamous cell carcinoma of the lung. Biopsy reveals normal
columnar epithelium replaced by stratified squamous epithelium in the bronchial lining. This change
represents:
A. Dysplasia
B. Metaplasia [CORRECT]
, C. Anaplasia
D. Hypertrophy
Correct Answer: B
Rationale: The correct answer is metaplasia, which is the reversible replacement of one differentiated
cell type with another that can better withstand a particular stressor. Chronic smoking irritation causes
bronchial columnar epithelium to transform into squamous epithelium as a protective adaptation. The
dysplasia option is incorrect because that describes disordered, pre-neoplastic cellular growth with
nuclear atypia, not a complete cell type change. The anaplasia option is incorrect because that refers to
loss of cellular differentiation characteristic of malignant tumors, not an adaptive change. The
hypertrophy option is incorrect because that involves enlargement of existing cells, not replacement
with a different cell type.
Q5. A patient with severe sepsis develops multiple organ dysfunction. Laboratory studies show elevated
lactate and metabolic acidosis. The cellular mechanism primarily responsible for organ failure is:
A. Apoptosis triggered by caspase activation
B. ATP depletion and cellular swelling from impaired oxidative phosphorylation [CORRECT]
C. Programmed cell death from tumor necrosis factor signaling
D. Lysosomal enzyme release causing autodigestion
Correct Answer: B
Rationale: The correct answer describes the core mechanism of septic shock-induced cellular injury,
where inadequate tissue perfusion and mitochondrial dysfunction lead to anaerobic metabolism, ATP
depletion, ion pump failure, and cellular swelling. The apoptosis option is incorrect because although
apoptosis occurs in sepsis, the acute organ dysfunction in severe sepsis is primarily from reversible
cellular injury due to energy failure, not programmed cell death. The programmed cell death from TNF
option is incorrect because while inflammatory cytokines contribute to sepsis pathophysiology, the
immediate organ failure stems from metabolic crisis, not TNF-mediated apoptosis. The lysosomal
enzyme option describes autophagy or autolysis, which occurs in late irreversible injury, not the primary
mechanism of acute sepsis-induced organ dysfunction.
Q6. A patient with systemic lupus erythematosus has a positive antinuclear antibody (ANA) test with
anti-double-stranded DNA specificity. The pathophysiology of this autoimmune disease involves:
A. Type I hypersensitivity mediated by IgE and mast cell degranulation
B. Type II hypersensitivity with antibody-mediated cytotoxicity
, C. Type III hypersensitivity from immune complex deposition [CORRECT]
D. Type IV hypersensitivity with T-cell mediated delayed response
Correct Answer: C
Rationale: The correct answer describes type III hypersensitivity, where autoantibodies form immune
complexes with nuclear antigens that deposit in tissues, activate complement, and cause inflammation
in kidneys, skin, and joints. The type I option is incorrect because that describes allergic reactions like
anaphylaxis and asthma, not SLE. The type II option is incorrect because although some SLE
manifestations involve antibody-mediated cytotoxicity, the primary mechanism is immune complex
deposition, not direct cell surface antibody attack. The type IV option is incorrect because that describes
T-cell mediated reactions like contact dermatitis and tuberculin response, not the autoantibody-driven
pathophysiology of lupus.
Q7. A patient develops anaphylaxis after eating shellfish. Within minutes, the patient experiences
hypotension, bronchospasm, and urticaria. The initial mediator released from mast cells is:
A. Interleukin-2
B. Histamine [CORRECT]
C. Tumor necrosis factor-alpha
D. Interferon-gamma
Correct Answer: B
Rationale: The correct answer is histamine, which is the primary preformed mediator released from
mast cell granules during IgE-mediated degranulation, causing vasodilation, increased vascular
permeability, bronchial smooth muscle contraction, and pruritus. The interleukin-2 option is incorrect
because that is a T-cell growth factor produced during adaptive immune responses, not an immediate
hypersensitivity mediator. The TNF-alpha option is incorrect because although it is produced in late-
phase reactions, it is not the initial rapid-release mediator responsible for acute anaphylaxis symptoms.
The interferon-gamma option is incorrect because that is a Th1 cytokine involved in macrophage
activation and intracellular pathogen defense, not allergic degranulation.
Q8. A patient with HIV infection has a CD4 count of 180 cells/mm³. The patient develops Pneumocystis
jirovecii pneumonia. This opportunistic infection occurs because:
A. B-lymphocyte antibody production is completely absent
B. Macrophage phagocytic function is selectively impaired
C. Helper T-cell mediated immunity is severely compromised [CORRECT]
