WGU D236 Pathophysiology
Objective Assessment Exam
2026/2027 | Verified Questions
and Answers for an A Grade
(Latest Update)
1. Question
What is Starling’s Law of Capillary Forces, and how does it
explain edema in a nutritionally deficient child?
CORRECT ANSWER:
Starling’s Law describes fluid movement across capillary membranes
through the opposing forces of hydrostatic pressure and
osmotic/oncotic pressure. Low blood protein levels reduce oncotic
pressure, allowing more fluid to move out of the capillaries into the
interstitial space, producing edema.
Rationale:
Hydrostatic pressure pushes fluid out of capillaries, while plasma
proteins—especially albumin—help pull fluid back into the vascular
space through oncotic pressure. In severe nutritional deficiency,
,reduced plasma protein concentration decreases oncotic pressure.
Consequently, fluid is less effectively retained within the bloodstream
and accumulates in the interstitial tissues, causing edema.
2. Question
How does the RAAS result in increased blood volume and
increased blood pressure?
CORRECT ANSWER:
Reduced renal perfusion stimulates renin release. Renin initiates
formation of angiotensin II, which causes vasoconstriction and
stimulates aldosterone release. Aldosterone increases sodium and
water reabsorption, increasing blood volume and blood pressure.
Rationale:
The RAAS is activated when the kidneys sense decreased perfusion.
Renin ultimately leads to angiotensin II formation. Angiotensin II
directly raises blood pressure through vasoconstriction and promotes
aldosterone secretion. Aldosterone causes the kidneys to retain
sodium and water, expanding circulating volume and further
increasing blood pressure.
3. Question
,How can hyperkalemia lead to cardiac arrest?
CORRECT ANSWER:
Severe hyperkalemia disrupts normal cardiac electrical activity and
can produce dangerous dysrhythmias that may progress to cardiac
arrest.
Rationale:
Potassium is essential for normal nerve and muscle electrical activity,
including cardiac muscle. Excess extracellular potassium alters the
cardiac membrane potential and interferes with normal conduction.
As hyperkalemia becomes severe, potentially fatal dysrhythmias can
develop, compromising effective cardiac pumping and potentially
resulting in cardiac arrest. The uploaded guide specifically identifies
the heart as particularly vulnerable to potassium-related electrical
disturbances.
4. Question
How can you distinguish respiratory acidosis/alkalosis from
metabolic acidosis/alkalosis using ABGs?
CORRECT ANSWER:
Respiratory disorders primarily involve PCO₂, whereas metabolic
disorders primarily involve HCO₃⁻. Increased PCO₂ indicates
respiratory acidosis; decreased PCO₂ indicates respiratory alkalosis.
, Rationale:
The lungs regulate carbon dioxide, making PCO₂ the major
respiratory component of acid-base balance. The kidneys and
metabolic processes regulate bicarbonate. Therefore, when pH and
PCO₂ move in opposite directions, the disturbance is respiratory.
When PCO₂ is normal or moves in the same direction as pH, the guide
identifies the disturbance as metabolic.
5. Question
Why is the anion gap increased in diabetic ketoacidosis or lactic
acidosis?
CORRECT ANSWER:
Ketones and lactic acid produce unmeasured anions that consume
bicarbonate during buffering, increasing the anion gap.
Rationale:
In DKA, ketone bodies accumulate; in lactic acidosis, lactate
accumulates. These acids contribute unmeasured negatively charged
particles to the blood. As hydrogen ions are buffered, bicarbonate is
consumed, while the additional unmeasured anions remain. This
produces an increased anion gap.
6. Question
Objective Assessment Exam
2026/2027 | Verified Questions
and Answers for an A Grade
(Latest Update)
1. Question
What is Starling’s Law of Capillary Forces, and how does it
explain edema in a nutritionally deficient child?
CORRECT ANSWER:
Starling’s Law describes fluid movement across capillary membranes
through the opposing forces of hydrostatic pressure and
osmotic/oncotic pressure. Low blood protein levels reduce oncotic
pressure, allowing more fluid to move out of the capillaries into the
interstitial space, producing edema.
Rationale:
Hydrostatic pressure pushes fluid out of capillaries, while plasma
proteins—especially albumin—help pull fluid back into the vascular
space through oncotic pressure. In severe nutritional deficiency,
,reduced plasma protein concentration decreases oncotic pressure.
Consequently, fluid is less effectively retained within the bloodstream
and accumulates in the interstitial tissues, causing edema.
2. Question
How does the RAAS result in increased blood volume and
increased blood pressure?
CORRECT ANSWER:
Reduced renal perfusion stimulates renin release. Renin initiates
formation of angiotensin II, which causes vasoconstriction and
stimulates aldosterone release. Aldosterone increases sodium and
water reabsorption, increasing blood volume and blood pressure.
Rationale:
The RAAS is activated when the kidneys sense decreased perfusion.
Renin ultimately leads to angiotensin II formation. Angiotensin II
directly raises blood pressure through vasoconstriction and promotes
aldosterone secretion. Aldosterone causes the kidneys to retain
sodium and water, expanding circulating volume and further
increasing blood pressure.
3. Question
,How can hyperkalemia lead to cardiac arrest?
CORRECT ANSWER:
Severe hyperkalemia disrupts normal cardiac electrical activity and
can produce dangerous dysrhythmias that may progress to cardiac
arrest.
Rationale:
Potassium is essential for normal nerve and muscle electrical activity,
including cardiac muscle. Excess extracellular potassium alters the
cardiac membrane potential and interferes with normal conduction.
As hyperkalemia becomes severe, potentially fatal dysrhythmias can
develop, compromising effective cardiac pumping and potentially
resulting in cardiac arrest. The uploaded guide specifically identifies
the heart as particularly vulnerable to potassium-related electrical
disturbances.
4. Question
How can you distinguish respiratory acidosis/alkalosis from
metabolic acidosis/alkalosis using ABGs?
CORRECT ANSWER:
Respiratory disorders primarily involve PCO₂, whereas metabolic
disorders primarily involve HCO₃⁻. Increased PCO₂ indicates
respiratory acidosis; decreased PCO₂ indicates respiratory alkalosis.
, Rationale:
The lungs regulate carbon dioxide, making PCO₂ the major
respiratory component of acid-base balance. The kidneys and
metabolic processes regulate bicarbonate. Therefore, when pH and
PCO₂ move in opposite directions, the disturbance is respiratory.
When PCO₂ is normal or moves in the same direction as pH, the guide
identifies the disturbance as metabolic.
5. Question
Why is the anion gap increased in diabetic ketoacidosis or lactic
acidosis?
CORRECT ANSWER:
Ketones and lactic acid produce unmeasured anions that consume
bicarbonate during buffering, increasing the anion gap.
Rationale:
In DKA, ketone bodies accumulate; in lactic acidosis, lactate
accumulates. These acids contribute unmeasured negatively charged
particles to the blood. As hydrogen ions are buffered, bicarbonate is
consumed, while the additional unmeasured anions remain. This
produces an increased anion gap.
6. Question
