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WGU D236 PATHOPHYSIOLOGY FINAL EXAM
2026 ALL QUESTIONS AND CORRECT
DETAILED ANSWERS WITH RATIONALES
ALREADY A GRADED WITH EXPERT
FEEDBACK |NEW AND REVISED
1. A patient with chronic alcoholism presents with ascites, jaundice, and peripheral
edema. Which pathophysiological mechanism best explains the development of
ascites in this patient?
A. Increased plasma oncotic pressure from hypoalbuminemia
B. Decreased synthesis of albumin leading to reduced plasma oncotic pressure
C. Increased antidiuretic hormone secretion causing water retention
D. Obstructive uropathy resulting in sodium retention
Rationale: In cirrhosis, hepatocyte damage impairs albumin synthesis, reducing
plasma oncotic pressure. This decreases the force that retains fluid within
capillaries, allowing fluid to leak into the peritoneal space. Options A is incorrect
because oncotic pressure is decreased, not increased. C and D are not primary
mechanisms for ascites in alcoholic liver disease.
2. A 65-year-old patient with heart failure is receiving furosemide. Laboratory
results show sodium 128 mEq/L, potassium 3.1 mEq/L, and chloride 90 mEq/L.
Which acid-base disturbance is most likely?
A. Metabolic acidosis
B. Metabolic alkalosis
C. Respiratory acidosis
D. Respiratory alkalosis
Rationale: Loop diuretics like furosemide increase renal excretion of chloride,
sodium, and potassium, leading to contraction alkalosis. Hypochloremia and
hypokalemia maintain metabolic alkalosis by stimulating hydrogen ion secretion.
Metabolic acidosis (A) would present with low bicarbonate. Respiratory disorders
(C, D) require primary pCO2 changes.
3. A patient with type 1 diabetes mellitus presents with nausea, vomiting, deep
rapid breathing, and a fruity odor on the breath. Arterial blood gas reveals pH 7.25,
pCO2 30 mmHg, HCO3- 12 mEq/L. What is the primary compensatory
,2|Page
mechanism occurring?
A. Increased alveolar ventilation to lower pCO2
B. Renal retention of bicarbonate
C. Increased cardiac output to buffer acids
D. Hepatic production of ketone bodies
Rationale: In diabetic ketoacidosis, metabolic acidosis triggers peripheral
chemoreceptors, increasing respiratory rate and depth (Kussmaul breathing) to
lower pCO2 as respiratory compensation. Renal compensation (B) takes hours to
days. Hepatic ketogenesis (D) causes, not compensates for, acidosis.
4. A patient sustains a traumatic injury with significant blood loss. Which cellular
response occurs within minutes to maintain mean arterial pressure?
A. Baroreceptor-mediated vasoconstriction and increased heart rate
B. Release of atrial natriuretic peptide causing diuresis
C. Activation of the renin-angiotensin-aldosterone system
D. Increased capillary hydrostatic pressure
Rationale: Baroreceptors in the carotid sinus and aortic arch detect decreased
pressure and trigger sympathetic activation, causing vasoconstriction and
tachycardia within seconds. RAAS activation (C) occurs but takes longer. ANP
(B) would lower pressure further.
5. A 52-year-old man with a 30-pack-year smoking history presents with a chronic
cough producing bloody sputum and unintentional weight loss. A chest CT reveals
a central lung mass. Which genetic abnormality is most commonly associated with
this presentation?
A. BRCA1 mutation
B. p53 tumor suppressor gene mutation
C. HER2/neu amplification
D. APC gene mutation
*Rationale: Small cell lung cancer and squamous cell carcinoma frequently
harbor p53 mutations, leading to loss of cell cycle arrest and apoptosis. BRCA1
(A) is associated with breast/ovarian cancer. HER2/neu (C) with breast cancer.
APC (D) with colorectal cancer.*
6. A patient with sickle cell disease develops sudden severe chest pain, fever, and
hypoxia. A chest radiograph shows a new pulmonary infiltrate. Which
pathophysiological process is the direct cause of this complication?
A. Pulmonary embolism from deep vein thrombosis
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B. Vaso-occlusion of pulmonary microvasculature by sickled erythrocytes
C. Fat embolism from bone marrow infarction
D. Bacterial pneumonia due to functional asplenia
Rationale: Acute chest syndrome in sickle cell disease results from in situ
sickling and vaso-occlusion in pulmonary vessels, leading to infarction and
inflammation. While infection (D) may occur, vaso-occlusion is the direct
mechanism. DVT/PE (A) is less common. Fat embolism (C) may occur but is not
the primary cause.
7. A 70-year-old female with osteoporosis falls and sustains a hip fracture. Which
cellular process is primarily responsible for her underlying bone fragility?
A. Increased osteoblast activity
B. Increased osteoclast activity relative to osteoblast activity
C. Decreased parathyroid hormone secretion
D. Excessive calcitonin release
Rationale: Osteoporosis results from bone resorption exceeding formation due to
increased osteoclast activity or decreased osteoblast function, often age-related
or estrogen-deficiency mediated. Increased osteoblast activity (A) would increase
bone density. PTH (C) usually increases with age. Calcitonin (D) inhibits
osteoclasts.
8. A patient with rheumatoid arthritis develops joint deformities including ulnar
deviation and swan-neck fingers. Which pathological process directly causes these
deformities?
A. Synovial pannus formation eroding articular cartilage and ligaments
B. Deposition of monosodium urate crystals in synovial fluid
C. Degeneration of articular cartilage due to mechanical stress
D. Autoantibodies against acetylcholine receptors
Rationale: Rheumatoid arthritis involves chronic synovial inflammation with
pannus (proliferative granulation tissue) that invades and destroys cartilage,
bone, and ligaments, leading to characteristic deformities. Urate crystals (B)
cause gout. Mechanical degeneration (C) describes osteoarthritis. Acetylceptor
antibodies (D) cause myasthenia gravis.
9. A 45-year-old man presents with episodic severe headache, palpitations,
diaphoresis, and hypertension. Laboratory tests show elevated plasma
metanephrines. Which tumor is most likely?
A. Pheochromocytoma
, 4|Page
B. Adrenocortical adenoma
C. Carcinoid tumor
D. Medullary thyroid carcinoma
Rationale: Pheochromocytoma, a catecholamine-secreting tumor of adrenal
medulla chromaffin cells, causes paroxysmal hypertension, headache,
palpitations, and diaphoresis with elevated metanephrines. Adrenocortical
adenoma (B) would secrete cortisol or aldosterone. Carcinoid (C) causes
flushing and diarrhea. Medullary thyroid (D) secretes calcitonin.
10. A patient with chronic kidney disease stage 4 has a serum phosphate of 6.2
mg/dL and calcium of 7.8 mg/dL. Which compensatory response is expected?
A. Increased parathyroid hormone secretion
B. Decreased vitamin D activation
C. Increased fibroblast growth factor-23
D. Decreased calcium excretion
*Rationale: Hyperphosphatemia and hypocalcemia stimulate PTH secretion
(secondary hyperparathyroidism) to increase phosphate excretion and calcium
resorption. Decreased vitamin D activation (B) occurs but is not compensatory.
FGF-23 (C) increases but its primary effect is phosphaturia. Calcium excretion
(D) is reduced but PTH is the key compensatory hormone.*
11. A newborn is diagnosed with cystic fibrosis after presenting with meconium
ileus. Which cellular transport defect is the underlying cause?
A. CFTR gene mutation causing defective chloride and bicarbonate transport
B. Deficiency of alpha-1 antitrypsin
C. Mutation in the phenylalanine hydroxylase gene
D. Defective sodium channel in respiratory epithelium
*Rationale: CFTR mutations impair chloride and bicarbonate transport across
epithelial cell membranes, leading to thickened secretions in lungs, pancreas,
and intestines. Alpha-1 antitrypsin deficiency (B) causes emphysema/liver
disease. PKU (C) involves phenylalanine metabolism. Option D describes a
different channel defect.*
12. A 60-year-old patient with hypertension and diabetes presents with a non-
healing ulcer on the plantar surface of the foot. Dorsalis pedis pulse is absent.
Which primary mechanism is responsible for this wound?
A. Venous insufficiency leading to stasis dermatitis
B. Peripheral arterial disease causing inadequate tissue perfusion
WGU D236 PATHOPHYSIOLOGY FINAL EXAM
2026 ALL QUESTIONS AND CORRECT
DETAILED ANSWERS WITH RATIONALES
ALREADY A GRADED WITH EXPERT
FEEDBACK |NEW AND REVISED
1. A patient with chronic alcoholism presents with ascites, jaundice, and peripheral
edema. Which pathophysiological mechanism best explains the development of
ascites in this patient?
A. Increased plasma oncotic pressure from hypoalbuminemia
B. Decreased synthesis of albumin leading to reduced plasma oncotic pressure
C. Increased antidiuretic hormone secretion causing water retention
D. Obstructive uropathy resulting in sodium retention
Rationale: In cirrhosis, hepatocyte damage impairs albumin synthesis, reducing
plasma oncotic pressure. This decreases the force that retains fluid within
capillaries, allowing fluid to leak into the peritoneal space. Options A is incorrect
because oncotic pressure is decreased, not increased. C and D are not primary
mechanisms for ascites in alcoholic liver disease.
2. A 65-year-old patient with heart failure is receiving furosemide. Laboratory
results show sodium 128 mEq/L, potassium 3.1 mEq/L, and chloride 90 mEq/L.
Which acid-base disturbance is most likely?
A. Metabolic acidosis
B. Metabolic alkalosis
C. Respiratory acidosis
D. Respiratory alkalosis
Rationale: Loop diuretics like furosemide increase renal excretion of chloride,
sodium, and potassium, leading to contraction alkalosis. Hypochloremia and
hypokalemia maintain metabolic alkalosis by stimulating hydrogen ion secretion.
Metabolic acidosis (A) would present with low bicarbonate. Respiratory disorders
(C, D) require primary pCO2 changes.
3. A patient with type 1 diabetes mellitus presents with nausea, vomiting, deep
rapid breathing, and a fruity odor on the breath. Arterial blood gas reveals pH 7.25,
pCO2 30 mmHg, HCO3- 12 mEq/L. What is the primary compensatory
,2|Page
mechanism occurring?
A. Increased alveolar ventilation to lower pCO2
B. Renal retention of bicarbonate
C. Increased cardiac output to buffer acids
D. Hepatic production of ketone bodies
Rationale: In diabetic ketoacidosis, metabolic acidosis triggers peripheral
chemoreceptors, increasing respiratory rate and depth (Kussmaul breathing) to
lower pCO2 as respiratory compensation. Renal compensation (B) takes hours to
days. Hepatic ketogenesis (D) causes, not compensates for, acidosis.
4. A patient sustains a traumatic injury with significant blood loss. Which cellular
response occurs within minutes to maintain mean arterial pressure?
A. Baroreceptor-mediated vasoconstriction and increased heart rate
B. Release of atrial natriuretic peptide causing diuresis
C. Activation of the renin-angiotensin-aldosterone system
D. Increased capillary hydrostatic pressure
Rationale: Baroreceptors in the carotid sinus and aortic arch detect decreased
pressure and trigger sympathetic activation, causing vasoconstriction and
tachycardia within seconds. RAAS activation (C) occurs but takes longer. ANP
(B) would lower pressure further.
5. A 52-year-old man with a 30-pack-year smoking history presents with a chronic
cough producing bloody sputum and unintentional weight loss. A chest CT reveals
a central lung mass. Which genetic abnormality is most commonly associated with
this presentation?
A. BRCA1 mutation
B. p53 tumor suppressor gene mutation
C. HER2/neu amplification
D. APC gene mutation
*Rationale: Small cell lung cancer and squamous cell carcinoma frequently
harbor p53 mutations, leading to loss of cell cycle arrest and apoptosis. BRCA1
(A) is associated with breast/ovarian cancer. HER2/neu (C) with breast cancer.
APC (D) with colorectal cancer.*
6. A patient with sickle cell disease develops sudden severe chest pain, fever, and
hypoxia. A chest radiograph shows a new pulmonary infiltrate. Which
pathophysiological process is the direct cause of this complication?
A. Pulmonary embolism from deep vein thrombosis
,3|Page
B. Vaso-occlusion of pulmonary microvasculature by sickled erythrocytes
C. Fat embolism from bone marrow infarction
D. Bacterial pneumonia due to functional asplenia
Rationale: Acute chest syndrome in sickle cell disease results from in situ
sickling and vaso-occlusion in pulmonary vessels, leading to infarction and
inflammation. While infection (D) may occur, vaso-occlusion is the direct
mechanism. DVT/PE (A) is less common. Fat embolism (C) may occur but is not
the primary cause.
7. A 70-year-old female with osteoporosis falls and sustains a hip fracture. Which
cellular process is primarily responsible for her underlying bone fragility?
A. Increased osteoblast activity
B. Increased osteoclast activity relative to osteoblast activity
C. Decreased parathyroid hormone secretion
D. Excessive calcitonin release
Rationale: Osteoporosis results from bone resorption exceeding formation due to
increased osteoclast activity or decreased osteoblast function, often age-related
or estrogen-deficiency mediated. Increased osteoblast activity (A) would increase
bone density. PTH (C) usually increases with age. Calcitonin (D) inhibits
osteoclasts.
8. A patient with rheumatoid arthritis develops joint deformities including ulnar
deviation and swan-neck fingers. Which pathological process directly causes these
deformities?
A. Synovial pannus formation eroding articular cartilage and ligaments
B. Deposition of monosodium urate crystals in synovial fluid
C. Degeneration of articular cartilage due to mechanical stress
D. Autoantibodies against acetylcholine receptors
Rationale: Rheumatoid arthritis involves chronic synovial inflammation with
pannus (proliferative granulation tissue) that invades and destroys cartilage,
bone, and ligaments, leading to characteristic deformities. Urate crystals (B)
cause gout. Mechanical degeneration (C) describes osteoarthritis. Acetylceptor
antibodies (D) cause myasthenia gravis.
9. A 45-year-old man presents with episodic severe headache, palpitations,
diaphoresis, and hypertension. Laboratory tests show elevated plasma
metanephrines. Which tumor is most likely?
A. Pheochromocytoma
, 4|Page
B. Adrenocortical adenoma
C. Carcinoid tumor
D. Medullary thyroid carcinoma
Rationale: Pheochromocytoma, a catecholamine-secreting tumor of adrenal
medulla chromaffin cells, causes paroxysmal hypertension, headache,
palpitations, and diaphoresis with elevated metanephrines. Adrenocortical
adenoma (B) would secrete cortisol or aldosterone. Carcinoid (C) causes
flushing and diarrhea. Medullary thyroid (D) secretes calcitonin.
10. A patient with chronic kidney disease stage 4 has a serum phosphate of 6.2
mg/dL and calcium of 7.8 mg/dL. Which compensatory response is expected?
A. Increased parathyroid hormone secretion
B. Decreased vitamin D activation
C. Increased fibroblast growth factor-23
D. Decreased calcium excretion
*Rationale: Hyperphosphatemia and hypocalcemia stimulate PTH secretion
(secondary hyperparathyroidism) to increase phosphate excretion and calcium
resorption. Decreased vitamin D activation (B) occurs but is not compensatory.
FGF-23 (C) increases but its primary effect is phosphaturia. Calcium excretion
(D) is reduced but PTH is the key compensatory hormone.*
11. A newborn is diagnosed with cystic fibrosis after presenting with meconium
ileus. Which cellular transport defect is the underlying cause?
A. CFTR gene mutation causing defective chloride and bicarbonate transport
B. Deficiency of alpha-1 antitrypsin
C. Mutation in the phenylalanine hydroxylase gene
D. Defective sodium channel in respiratory epithelium
*Rationale: CFTR mutations impair chloride and bicarbonate transport across
epithelial cell membranes, leading to thickened secretions in lungs, pancreas,
and intestines. Alpha-1 antitrypsin deficiency (B) causes emphysema/liver
disease. PKU (C) involves phenylalanine metabolism. Option D describes a
different channel defect.*
12. A 60-year-old patient with hypertension and diabetes presents with a non-
healing ulcer on the plantar surface of the foot. Dorsalis pedis pulse is absent.
Which primary mechanism is responsible for this wound?
A. Venous insufficiency leading to stasis dermatitis
B. Peripheral arterial disease causing inadequate tissue perfusion
