,WGU D236 Objective Assessment Pathophysiology 2026/2027
Questions And Answers
Q1. A child with severe protein malnutrition develops generalized
edema. Which mechanism most directly explains the fluid shift?
A) Reduced plasma oncotic pressure from hypoalbuminemia
B) Increased plasma oncotic pressure
C) Decreased capillary hydrostatic pressure
D) Increased intracellular potassium concentration
Correct Answer: A) Reduced plasma oncotic pressure from hypoalbuminemia
Rationale: Albumin provides much of the plasma oncotic force that draws
water into capillaries. Severe hypoalbuminemia reduces this pulling force,
allowing fluid to accumulate in interstitial tissues.
Q2. Which change most directly stimulates renin release from the
kidneys?
A) Increased renal perfusion pressure
B) Hypervolemia
C) Increased sodium delivery to the distal nephron
D) Decreased renal perfusion
Correct Answer: D) Decreased renal perfusion
Rationale: Reduced renal blood flow activates renin release, initiating the
renin-angiotensin-aldosterone system to restore circulating volume and blood
pressure.
Q3. What is the major effect of aldosterone?
A) Increase sodium excretion and retain potassium
B) Promote free-water loss only
C) Increase sodium and water retention while promoting potassium excretion
D) Suppress renal sodium reabsorption
Correct Answer: C) Increase sodium and water retention while promoting
potassium excretion
Rationale: Aldosterone acts on the distal nephron to increase sodium
reabsorption and potassium secretion. Water follows retained sodium,
increasing extracellular volume.
,Q4. Which hormone primarily increases renal water reabsorption in
response to increased serum osmolality?
A) Insulin
B) Antidiuretic hormone
C) Thyroxine
D) Parathyroid hormone
Correct Answer: B) Antidiuretic hormone
Rationale: ADH increases water permeability in the collecting ducts,
allowing the kidneys to conserve water and lower serum osmolality.
Q5. Which electrolyte disturbance is most strongly associated with
peaked T waves and life-threatening cardiac dysrhythmias?
A) Hyponatremia
B) Hypocalcemia
C) Hyperkalemia
D) Hypermagnesemia
Correct Answer: C) Hyperkalemia
Rationale: Excess extracellular potassium alters cardiac membrane
excitability and can produce peaked T waves, conduction abnormalities, and
fatal dysrhythmias.
Q6. Which finding is most consistent with hypocalcemia?
A) Positive Trousseau sign
B) Depressed neuromuscular activity
C) Severe constipation only
D) Flaccid paralysis without tetany
Correct Answer: A) Positive Trousseau sign
Rationale: Low calcium increases neuromuscular excitability, producing
manifestations such as tetany, paresthesias, and positive Chvostek or
Trousseau signs.
Q7. Which process moves water across a semipermeable membrane
toward an area of higher solute concentration?
A) Active transport
B) Filtration
, C) Osmosis
D) Phagocytosis
Correct Answer: C) Osmosis
Rationale: Osmosis is passive movement of water across a semipermeable
membrane toward the side containing a higher effective solute
concentration.
Q8. Which process describes movement of particles from an area of
higher concentration to an area of lower concentration without
energy expenditure?
A) Endocytosis
B) Diffusion
C) Active transport
D) Pinocytosis
Correct Answer: B) Diffusion
Rationale: Diffusion is passive movement down a concentration gradient
and does not require ATP.
Q9. A patient has pH 7.29, PaCO₂ 52 mm Hg, and elevated
bicarbonate from compensation. Which primary disorder is present?
A) Respiratory acidosis
B) Respiratory alkalosis
C) Metabolic acidosis
D) Metabolic alkalosis
Correct Answer: A) Respiratory acidosis
Rationale: Carbon dioxide retention increases carbonic acid and lowers pH.
Renal bicarbonate retention can partially compensate when the disturbance
persists.
Q10. Prolonged vomiting most commonly predisposes a patient to
which acid-base disorder?
A) Respiratory acidosis
B) Metabolic acidosis
C) Respiratory alkalosis
D) Metabolic alkalosis
Correct Answer: D) Metabolic alkalosis
Questions And Answers
Q1. A child with severe protein malnutrition develops generalized
edema. Which mechanism most directly explains the fluid shift?
A) Reduced plasma oncotic pressure from hypoalbuminemia
B) Increased plasma oncotic pressure
C) Decreased capillary hydrostatic pressure
D) Increased intracellular potassium concentration
Correct Answer: A) Reduced plasma oncotic pressure from hypoalbuminemia
Rationale: Albumin provides much of the plasma oncotic force that draws
water into capillaries. Severe hypoalbuminemia reduces this pulling force,
allowing fluid to accumulate in interstitial tissues.
Q2. Which change most directly stimulates renin release from the
kidneys?
A) Increased renal perfusion pressure
B) Hypervolemia
C) Increased sodium delivery to the distal nephron
D) Decreased renal perfusion
Correct Answer: D) Decreased renal perfusion
Rationale: Reduced renal blood flow activates renin release, initiating the
renin-angiotensin-aldosterone system to restore circulating volume and blood
pressure.
Q3. What is the major effect of aldosterone?
A) Increase sodium excretion and retain potassium
B) Promote free-water loss only
C) Increase sodium and water retention while promoting potassium excretion
D) Suppress renal sodium reabsorption
Correct Answer: C) Increase sodium and water retention while promoting
potassium excretion
Rationale: Aldosterone acts on the distal nephron to increase sodium
reabsorption and potassium secretion. Water follows retained sodium,
increasing extracellular volume.
,Q4. Which hormone primarily increases renal water reabsorption in
response to increased serum osmolality?
A) Insulin
B) Antidiuretic hormone
C) Thyroxine
D) Parathyroid hormone
Correct Answer: B) Antidiuretic hormone
Rationale: ADH increases water permeability in the collecting ducts,
allowing the kidneys to conserve water and lower serum osmolality.
Q5. Which electrolyte disturbance is most strongly associated with
peaked T waves and life-threatening cardiac dysrhythmias?
A) Hyponatremia
B) Hypocalcemia
C) Hyperkalemia
D) Hypermagnesemia
Correct Answer: C) Hyperkalemia
Rationale: Excess extracellular potassium alters cardiac membrane
excitability and can produce peaked T waves, conduction abnormalities, and
fatal dysrhythmias.
Q6. Which finding is most consistent with hypocalcemia?
A) Positive Trousseau sign
B) Depressed neuromuscular activity
C) Severe constipation only
D) Flaccid paralysis without tetany
Correct Answer: A) Positive Trousseau sign
Rationale: Low calcium increases neuromuscular excitability, producing
manifestations such as tetany, paresthesias, and positive Chvostek or
Trousseau signs.
Q7. Which process moves water across a semipermeable membrane
toward an area of higher solute concentration?
A) Active transport
B) Filtration
, C) Osmosis
D) Phagocytosis
Correct Answer: C) Osmosis
Rationale: Osmosis is passive movement of water across a semipermeable
membrane toward the side containing a higher effective solute
concentration.
Q8. Which process describes movement of particles from an area of
higher concentration to an area of lower concentration without
energy expenditure?
A) Endocytosis
B) Diffusion
C) Active transport
D) Pinocytosis
Correct Answer: B) Diffusion
Rationale: Diffusion is passive movement down a concentration gradient
and does not require ATP.
Q9. A patient has pH 7.29, PaCO₂ 52 mm Hg, and elevated
bicarbonate from compensation. Which primary disorder is present?
A) Respiratory acidosis
B) Respiratory alkalosis
C) Metabolic acidosis
D) Metabolic alkalosis
Correct Answer: A) Respiratory acidosis
Rationale: Carbon dioxide retention increases carbonic acid and lowers pH.
Renal bicarbonate retention can partially compensate when the disturbance
persists.
Q10. Prolonged vomiting most commonly predisposes a patient to
which acid-base disorder?
A) Respiratory acidosis
B) Metabolic acidosis
C) Respiratory alkalosis
D) Metabolic alkalosis
Correct Answer: D) Metabolic alkalosis
