WGU D236 Pathophysiology Exam Complete
Actual Exam Versions A, B & C – 400
Questions with Verified Detailed Correct
Answers
Official Exam Overview:
The WGU D236 OA evaluates learners’ understanding of pathophysiology concepts, including
mechanisms of disease, cellular and systemic dysfunction, and clinical correlations. The exam
emphasizes interpretation of diagnostic data, understanding compensatory mechanisms, and
analyzing disease progression.
Exam Coverage Areas:
• Acid-base and electrolyte disorders
• Respiratory and cardiovascular pathophysiology
• Renal and metabolic regulation
• Immune and hematologic system dysfunction
• Neurologic and musculoskeletal disorders
• Homeostatic adaptations and compensatory responses
QUESTION 1:
An ICU patient’s arterial blood gas (ABG) shows low pH and low CO₂. The patient’s respiratory
rate is elevated. Which condition does this indicate?
A) Respiratory acidosis
B) Metabolic acidosis ✅
C) Metabolic alkalosis
D) Respiratory alkalosis
Rationale:
• Low pH indicates acidosis.
• Low CO₂ indicates the lungs are not the primary cause; CO₂ is moving opposite the pH trend.
• This pattern defines metabolic acidosis, with the elevated respiratory rate acting as a
compensatory mechanism to remove CO₂ and partially correct pH.
QUESTION 2:
Which compensatory mechanism occurs in metabolic acidosis?
A) Hypoventilation to retain CO₂
B) Hyperventilation to decrease CO₂ ✅
,C) Kidney excretion of bicarbonate
D) Decreased heart rate
Rationale:
In metabolic acidosis, the respiratory system compensates by increasing ventilation, which lowers
CO₂ (a volatile acid), helping to raise pH toward normal. Hypoventilation or slowing the heart rate
does not correct acidosis.
QUESTION 3:
A patient has high pH and high HCO₃⁻ on their ABG. What is the primary disorder?
A) Respiratory acidosis
B) Metabolic acidosis
C) Metabolic alkalosis ✅
D) Respiratory alkalosis
Rationale:
• High pH indicates alkalosis.
• High bicarbonate (HCO₃⁻) indicates a metabolic origin.
• This combination defines metabolic alkalosis, which may result from excessive vomiting,
diuretic use, or bicarbonate administration.
QUESTION 4:
Which organ is primarily responsible for long-term compensation of acid-base disturbances?
A) Lungs
B) Heart
C) Kidneys ✅
D) Liver
Rationale:
The kidneys regulate acid-base balance long-term by excreting hydrogen ions and reabsorbing
bicarbonate. The lungs provide short-term compensation by adjusting CO₂ levels. Heart and liver
are not primary regulators of pH.
QUESTION 5:
A patient presents with low pH, high CO₂, and normal HCO₃⁻. What is the primary acid-base
disorder?
A) Respiratory acidosis ✅
B) Metabolic acidosis
C) Metabolic alkalosis
D) Respiratory alkalosis
Rationale:
, • Low pH indicates acidosis.
• High CO₂ indicates a respiratory origin.
• Normal bicarbonate indicates the kidneys have not yet compensated.
• This pattern defines acute respiratory acidosis, commonly caused by hypoventilation,
airway obstruction, or lung disease.
An ICU patient's arterial blood gas results show low pH and low CO2 levels. The patient's
respiratory rate is increased.
What is the name of this condition?
Respiratory acidosis
Metabolic acidosis
Metabolic alkalosis
Respiratory alkalosis - ANSWER-Metabolic acidosis
Rational: Since the pH is low, and the pH and CO2 are trending in the same direction, the
condition is metabolic acidosis. The low CO2 indicates that CO2 is not causing the acidosis. The
increased respiratory rate lowers blood CO2 in an attempt to compensate for the metabolic
acidosis.
Your patient has type I diabetes and has developed kidney disease requiring dialysis. The
patient is diligent about caring for themselves and wants to maintain as much independence as
possible.
What course of treatment would address the patient's kidney disease while allowing the
patient to care for this condition at home?
1
, Page 2 of 130
Hemodialysis
Peritoneal dialysis
Sugar tablets
An insulin pump - ANSWER-Peritoneal dialysis
Your patient has pulmonary edema, which raises levels of CO2 in the blood.
What helps the patient's body to compensate for this increase?
The kidneys conserve both H+ and HCO3-.
The kidneys excrete more H+ and more HCO3-.
The kidneys conserve H+ and excrete more HCO3-.
The kidneys excrete more H+ and conserve HCO3-. - ANSWER-The kidneys excrete more H+ and
conserve HCO3-.
Your patient was stung by a bee, and his ankle is red and swollen. The inflammatory response is
causing the redness and swelling.
What is unlikely to occur?
Antihistamines are released by mast cells at the site of the sting.
Vasoconstriction at the site of the sting, causing fluid to accumulate.
2