WGU D115 OA Advanced Pathophysiology
Exam (Latest 2026) Actual Questions with
Detailed Answers and OA Readiness Practice
Exam
WGU D115 — Advanced Pathophysiology for the Advanced Practice Nurse
Advanced Pathophysiology (Graduate Nursing / APRN)
SECTION I: FOUNDATIONAL MECHANISMS AND MULTISYSTEM
PATHOPHYSIOLOGY
1. A 58-year-old male with a 40-pack-year smoking history undergoes bronchial
biopsy. Pathology reports replacement of normal pseudostratified ciliated
columnar epithelium with stratified squamous epithelium. Which cellular
adaptation does this represent?
A) Hyperplasia
B) Metaplasia
C) Dysplasia
D) Atrophy
Rationale: Metaplasia is the reversible replacement of one mature epithelial cell
type with another better suited to withstand chronic irritation. Squamous
metaplasia in the smoker's airway is an adaptive response, but it creates a field
vulnerable to progression to dysplasia and carcinoma.
2. A 62-year-old female with long-standing hypertension has increased left
ventricular wall thickness documented on echocardiogram. The myocytes are
larger but not more numerous. Which adaptation is this?
A) Hypertrophy
B) Hyperplasia
,C) Metaplasia
D) Dysplasia
Rationale: Cardiac myocytes are permanent cells and cannot divide. In response to
increased afterload, they increase in size (hypertrophy) rather than number
(hyperplasia).
3. A 24-year-old male sustains a crush injury to the thigh. Several days later he
develops dark urine, elevated creatine kinase, and acute kidney injury. Which
mechanism best explains the renal injury?
A) Myoglobin-induced acute tubular necrosis
B) Postrenal obstruction from hematoma
C) Prerenal azotemia from hemorrhage alone
D) Acute interstitial nephritis
Rationale: Rhabdomyolysis releases myoglobin, which is filtered by the glomerulus
and is directly toxic to tubular epithelial cells, causing acute tubular necrosis.
Myoglobin also casts and obstructs tubules.
4. A 70-year-old female with a hip fracture after a fall has a hemoglobin of 10.8
g/dL, MCV 92 fL, and reticulocyte count 3.5%. Which classification best describes
this anemia?
A) Acute blood loss anemia, normocytic
B) Iron deficiency anemia, microcytic
C) Megaloblastic anemia, macrocytic
D) Aplastic anemia
Rationale: Acute blood loss produces a normocytic, normochromic anemia. The
reticulocyte count rises as the marrow responds, provided iron stores and
erythropoietin are adequate.
5. A 35-year-old female presents with fatigue, weight gain, cold intolerance, and
constipation. TSH is elevated and free T4 is low. Which mechanism explains these
findings?
A) Primary hypothyroidism with loss of negative feedback
B) Secondary hypothyroidism from pituitary failure
C) Tertiary hypothyroidism from hypothalamic failure
,D) Subclinical hyperthyroidism
Rationale: In primary hypothyroidism, the thyroid gland cannot produce T4. The
resulting low T4 removes negative feedback on the pituitary, causing TSH to rise.
In secondary and tertiary hypothyroidism, TSH is low or inappropriately normal.
6. A patient with severe vomiting has an ABG showing pH 7.52, PaCO₂ 50 mm Hg,
and HCO₃⁻ 38 mEq/L. Which interpretation is correct?
A) Metabolic alkalosis with respiratory compensation
B) Respiratory alkalosis with metabolic compensation
C) Metabolic acidosis with respiratory compensation
D) Mixed respiratory and metabolic alkalosis
Rationale: The pH is alkalemic and the bicarbonate is elevated, indicating a
metabolic alkalosis. The PaCO₂ is elevated as the lungs hypoventilate to retain CO₂
and bring pH toward normal—an appropriate respiratory compensation.
7. A 68-year-old male with benign prostatic hyperplasia presents with a distended
bladder, bilateral hydronephrosis, and rising creatinine. Which category of acute
kidney injury is this?
A) Prerenal
B) Postrenal
C) Intrarenal
D) Intrinsic
Rationale: Postrenal AKI results from obstruction to urine flow distal to the kidney.
Bladder outlet obstruction from BPH causes bilateral hydronephrosis and rising
creatinine.
8. A 22-year-old with type 1 diabetes presents with nausea, vomiting, abdominal
pain, and Kussmaul respirations. Glucose is 480 mg/dL, pH 7.18, PaCO₂ 22 mm Hg,
HCO₃⁻ 8 mEq/L, and urine ketones are large. Which pathophysiologic sequence is
most accurate?
A) Insulin deficiency → lipolysis → ketone production → high anion gap
metabolic acidosis
B) Insulin resistance → hyperglycemia → osmotic diuresis → hypochloremic
metabolic alkalosis
, C) Glucagon deficiency → hypoglycemia → lactic acidosis
D) Excess insulin → cellular potassium uptake → respiratory acidosis
Rationale: Absolute insulin deficiency permits unrestrained lipolysis and hepatic
ketogenesis. Ketone bodies are acids that consume bicarbonate, producing a high
anion gap metabolic acidosis. Kussmaul breathing is the respiratory
compensation.
9. A patient with advanced COPD has an ABG of pH 7.35, PaCO₂ 62 mm Hg, and
HCO₃⁻ 34 mEq/L. Which interpretation is most accurate?
A) Compensated respiratory acidosis
B) Uncompensated respiratory acidosis
C) Primary metabolic alkalosis
D) Acute respiratory alkalosis
Rationale: The PaCO₂ is elevated, indicating respiratory acidosis. The pH is near
normal, and the bicarbonate is elevated, indicating renal compensation (metabolic
alkalosis) that has restored the pH toward the normal range.
10. A 55-year-old male with cirrhosis has ascites, jaundice, and confusion.
Albumin is 2.1 g/dL and INR is 1.9. Which combination best explains ascites
formation?
A) Portal hypertension increases hydrostatic pressure and hypoalbuminemia
decreases oncotic pressure
B) Increased capillary permeability from histamine release
C) Lymphatic obstruction by tumor
D) Isolated sodium retention with normal Starling forces
Rationale: Ascites in cirrhosis reflects two Starling forces acting together: elevated
portal hydrostatic pressure drives fluid into the peritoneum, and reduced plasma
oncotic pressure from hypoalbuminemia favors fluid leaving the vasculature.
11. A 28-year-old female presents with fever, flank pain, and costovertebral angle
tenderness after several days of dysuria. Urinalysis shows pyuria and bacteriuria.
Which diagnosis is most likely?
A) Cystitis
B) Pyelonephritis
Exam (Latest 2026) Actual Questions with
Detailed Answers and OA Readiness Practice
Exam
WGU D115 — Advanced Pathophysiology for the Advanced Practice Nurse
Advanced Pathophysiology (Graduate Nursing / APRN)
SECTION I: FOUNDATIONAL MECHANISMS AND MULTISYSTEM
PATHOPHYSIOLOGY
1. A 58-year-old male with a 40-pack-year smoking history undergoes bronchial
biopsy. Pathology reports replacement of normal pseudostratified ciliated
columnar epithelium with stratified squamous epithelium. Which cellular
adaptation does this represent?
A) Hyperplasia
B) Metaplasia
C) Dysplasia
D) Atrophy
Rationale: Metaplasia is the reversible replacement of one mature epithelial cell
type with another better suited to withstand chronic irritation. Squamous
metaplasia in the smoker's airway is an adaptive response, but it creates a field
vulnerable to progression to dysplasia and carcinoma.
2. A 62-year-old female with long-standing hypertension has increased left
ventricular wall thickness documented on echocardiogram. The myocytes are
larger but not more numerous. Which adaptation is this?
A) Hypertrophy
B) Hyperplasia
,C) Metaplasia
D) Dysplasia
Rationale: Cardiac myocytes are permanent cells and cannot divide. In response to
increased afterload, they increase in size (hypertrophy) rather than number
(hyperplasia).
3. A 24-year-old male sustains a crush injury to the thigh. Several days later he
develops dark urine, elevated creatine kinase, and acute kidney injury. Which
mechanism best explains the renal injury?
A) Myoglobin-induced acute tubular necrosis
B) Postrenal obstruction from hematoma
C) Prerenal azotemia from hemorrhage alone
D) Acute interstitial nephritis
Rationale: Rhabdomyolysis releases myoglobin, which is filtered by the glomerulus
and is directly toxic to tubular epithelial cells, causing acute tubular necrosis.
Myoglobin also casts and obstructs tubules.
4. A 70-year-old female with a hip fracture after a fall has a hemoglobin of 10.8
g/dL, MCV 92 fL, and reticulocyte count 3.5%. Which classification best describes
this anemia?
A) Acute blood loss anemia, normocytic
B) Iron deficiency anemia, microcytic
C) Megaloblastic anemia, macrocytic
D) Aplastic anemia
Rationale: Acute blood loss produces a normocytic, normochromic anemia. The
reticulocyte count rises as the marrow responds, provided iron stores and
erythropoietin are adequate.
5. A 35-year-old female presents with fatigue, weight gain, cold intolerance, and
constipation. TSH is elevated and free T4 is low. Which mechanism explains these
findings?
A) Primary hypothyroidism with loss of negative feedback
B) Secondary hypothyroidism from pituitary failure
C) Tertiary hypothyroidism from hypothalamic failure
,D) Subclinical hyperthyroidism
Rationale: In primary hypothyroidism, the thyroid gland cannot produce T4. The
resulting low T4 removes negative feedback on the pituitary, causing TSH to rise.
In secondary and tertiary hypothyroidism, TSH is low or inappropriately normal.
6. A patient with severe vomiting has an ABG showing pH 7.52, PaCO₂ 50 mm Hg,
and HCO₃⁻ 38 mEq/L. Which interpretation is correct?
A) Metabolic alkalosis with respiratory compensation
B) Respiratory alkalosis with metabolic compensation
C) Metabolic acidosis with respiratory compensation
D) Mixed respiratory and metabolic alkalosis
Rationale: The pH is alkalemic and the bicarbonate is elevated, indicating a
metabolic alkalosis. The PaCO₂ is elevated as the lungs hypoventilate to retain CO₂
and bring pH toward normal—an appropriate respiratory compensation.
7. A 68-year-old male with benign prostatic hyperplasia presents with a distended
bladder, bilateral hydronephrosis, and rising creatinine. Which category of acute
kidney injury is this?
A) Prerenal
B) Postrenal
C) Intrarenal
D) Intrinsic
Rationale: Postrenal AKI results from obstruction to urine flow distal to the kidney.
Bladder outlet obstruction from BPH causes bilateral hydronephrosis and rising
creatinine.
8. A 22-year-old with type 1 diabetes presents with nausea, vomiting, abdominal
pain, and Kussmaul respirations. Glucose is 480 mg/dL, pH 7.18, PaCO₂ 22 mm Hg,
HCO₃⁻ 8 mEq/L, and urine ketones are large. Which pathophysiologic sequence is
most accurate?
A) Insulin deficiency → lipolysis → ketone production → high anion gap
metabolic acidosis
B) Insulin resistance → hyperglycemia → osmotic diuresis → hypochloremic
metabolic alkalosis
, C) Glucagon deficiency → hypoglycemia → lactic acidosis
D) Excess insulin → cellular potassium uptake → respiratory acidosis
Rationale: Absolute insulin deficiency permits unrestrained lipolysis and hepatic
ketogenesis. Ketone bodies are acids that consume bicarbonate, producing a high
anion gap metabolic acidosis. Kussmaul breathing is the respiratory
compensation.
9. A patient with advanced COPD has an ABG of pH 7.35, PaCO₂ 62 mm Hg, and
HCO₃⁻ 34 mEq/L. Which interpretation is most accurate?
A) Compensated respiratory acidosis
B) Uncompensated respiratory acidosis
C) Primary metabolic alkalosis
D) Acute respiratory alkalosis
Rationale: The PaCO₂ is elevated, indicating respiratory acidosis. The pH is near
normal, and the bicarbonate is elevated, indicating renal compensation (metabolic
alkalosis) that has restored the pH toward the normal range.
10. A 55-year-old male with cirrhosis has ascites, jaundice, and confusion.
Albumin is 2.1 g/dL and INR is 1.9. Which combination best explains ascites
formation?
A) Portal hypertension increases hydrostatic pressure and hypoalbuminemia
decreases oncotic pressure
B) Increased capillary permeability from histamine release
C) Lymphatic obstruction by tumor
D) Isolated sodium retention with normal Starling forces
Rationale: Ascites in cirrhosis reflects two Starling forces acting together: elevated
portal hydrostatic pressure drives fluid into the peritoneum, and reduced plasma
oncotic pressure from hypoalbuminemia favors fluid leaving the vasculature.
11. A 28-year-old female presents with fever, flank pain, and costovertebral angle
tenderness after several days of dysuria. Urinalysis shows pyuria and bacteriuria.
Which diagnosis is most likely?
A) Cystitis
B) Pyelonephritis
