1 | Page
WGU pathophysiology D236 Questions and
Answers
What is Starling's Law of Capillary forces?
How does this explain why a nutritionally deficient child would
have edema?
Ans: Starling's Law describes how fluids move across the capillary
membrane. There are two major opposing forces that act to balance each
other, hydrostatic pressure (pushing water out of the capillaries) and
osmotic pressure (including oncontic pressure, which pushes fluid into
the capillaries).
Both electrolytes and proteins (oncontic pressure) in the blood affect
osmotic pressure, high electrolyte and protein concentrations in the
blood would cause water to leave the cells and interstitial space and
enter the blood stream to dilute the high concentrations.
On, the other hand, low electrolyte and protein concentrations (as seen
in a nutritionally deficient child) would cause water to leave the
capillaries and enter the cells and interstitial fluid which can lead to
edema.
How does the RAAS (Renin-Angiotensin-Aldosterone System)
result in increased blood volume and increased blood pressure?
© 2025 All rights reserved
, 2 | Page
Ans: A drop in blood pressure is sensed by the kidneys by low
perfusion, which in turn begins to secrete renin.
Renin then triggers the liver to produce angiotensinogen, which is
converted to Angiotensin I in the lungs and then angiotensin II by the
enzyme
Angiotensin-converting enzyme (ACE). Angiotensin II stimulates
peripheral arterial vasoconstriction which raises BP.
Angiotensin II is also stimulating the adrenal gland to release
aldosterone, which acts to increase sodium and water reabsorption
increasing blood volume, while also increased potassium secretion in
urine.
How can hyperkalemia lead to cardiac arrest?
Ans: Normal levels of potassium are between 3.5 and 5.2 mEq/dL.
Hyperkalemia refers to potassium levels higher that 5.2 mEq/dL.
A major function of potassium is to conduct nerve impulses in muscles.
Too low and muscle weakness occurs and too much can cause muscle
spasms.
This is especially dangerous in the heart muscle and an irregular
heartbeat can cause a heart attack
The body uses the Protein Buffering System, Phosphate Buffering
System, and Carbonic Acid-Bicarbonate System to regulate and
maintain homeostatic pH, what is the consequence of a pH
imbalance
Ans: Proteins contain many acidic and basic group that can be affected
by pH changes. Any increase or decrease in blood pH can alter the
structure of the protein (denature), thereby affecting its function as well
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, 3 | Page
Describe the laboratory findings associated with metabolic
acidosis, metabolic alkalosis, respiratory acidosis and respiratory
alkalosis. (ie relative pH and CO2 levels).
Ans: Normal ABGs (Arterial Blood Gases) Blood pH: 7.35-7.45 PCO2: 35-
45 mm Hg PO2: 90-100 mm Hg HCO3-: 22-26 mEq/L SaO2: 95-100%
Respiratory acidosis and alkalosis are marked by changes in PCO2.
Higher = acidosis and lower = alkalosis
Metabolic acidosis and alkalosis are caused by something other than
abnormal CO2 levels. This could include toxicity, diabetes, renal failure
or excessive GI losses.
Here are the rules to follow to determine if is respiratory or metabolic in
nature. -If pH and PCO2 are moving in opposite directions, then it is the
pCO2 levels that are causing the imbalance and it is respiratory in
nature.
-If PCO2 is normal or is moving in the same direction as the pH, then the
imbalance is metabolic in nature.
The anion gap is the difference between measured cations (Na+
and K+) and measured anions (Cl- and HCO3-), this calculation can
be useful in determining the cause of metabolic acidosis.
Why would an increased anion gap be observed in diabetic
ketoacidosis or lactic acidosis?
Ans: The anion gap is the calculation of unmeasured anions in the
blood.
Lactic acid and ketones both lead to the production of unmeasured
anions, which remove HCO3- (a measured anion) due to buffering of the
excess H+ and therefore leads to an increase in the AG.
© 2025 All rights reserved
, 4 | Page
Why is it important to maintain a homeostatic balance of glucose
in the blood (ie describe the pathogenesis of diabetes)?
Ans: Insulin is the hormone responsible for initiating the uptake of
glucose by the cells. Cells use glucose to produce energy (ATP).
In a normal individual, when blood glucose increases, the pancreas is
signaled to produced in insulin, which binds to insulin receptors on a
cells surface and initiates the uptake of glucose.
Glucose is a very reactive molecule and if left in the blood, it can start to
bind to other proteins and lipids, which can lead to loss of function.
AGEs are advanced glycation end products that are a result of glucose
reacting with the endothelial lining, which can lead to damage in the
heart and kidneys.
Compare and contrast Type I and Type II Diabetes
Ans: Type I diabetes is caused by lack of insulin. With out insulin
signaling, glucose will not be taken into the cell and leads to high blood
glucose (hyperglycemia). Type I is usually treated with insulin injections.
Type II diabetes is caused by a desensitization to insulin signaling. The
insulin receptors are no longer responding to insulin, which also leads to
hyperglycemia.
Type II is usually treated with drugs to increase the sensitization to
insulin (metformin), dietary and life-style changes or insulin injections.
Describe some reasons for a patient needing dialysis
© 2025 All rights reserved
WGU pathophysiology D236 Questions and
Answers
What is Starling's Law of Capillary forces?
How does this explain why a nutritionally deficient child would
have edema?
Ans: Starling's Law describes how fluids move across the capillary
membrane. There are two major opposing forces that act to balance each
other, hydrostatic pressure (pushing water out of the capillaries) and
osmotic pressure (including oncontic pressure, which pushes fluid into
the capillaries).
Both electrolytes and proteins (oncontic pressure) in the blood affect
osmotic pressure, high electrolyte and protein concentrations in the
blood would cause water to leave the cells and interstitial space and
enter the blood stream to dilute the high concentrations.
On, the other hand, low electrolyte and protein concentrations (as seen
in a nutritionally deficient child) would cause water to leave the
capillaries and enter the cells and interstitial fluid which can lead to
edema.
How does the RAAS (Renin-Angiotensin-Aldosterone System)
result in increased blood volume and increased blood pressure?
© 2025 All rights reserved
, 2 | Page
Ans: A drop in blood pressure is sensed by the kidneys by low
perfusion, which in turn begins to secrete renin.
Renin then triggers the liver to produce angiotensinogen, which is
converted to Angiotensin I in the lungs and then angiotensin II by the
enzyme
Angiotensin-converting enzyme (ACE). Angiotensin II stimulates
peripheral arterial vasoconstriction which raises BP.
Angiotensin II is also stimulating the adrenal gland to release
aldosterone, which acts to increase sodium and water reabsorption
increasing blood volume, while also increased potassium secretion in
urine.
How can hyperkalemia lead to cardiac arrest?
Ans: Normal levels of potassium are between 3.5 and 5.2 mEq/dL.
Hyperkalemia refers to potassium levels higher that 5.2 mEq/dL.
A major function of potassium is to conduct nerve impulses in muscles.
Too low and muscle weakness occurs and too much can cause muscle
spasms.
This is especially dangerous in the heart muscle and an irregular
heartbeat can cause a heart attack
The body uses the Protein Buffering System, Phosphate Buffering
System, and Carbonic Acid-Bicarbonate System to regulate and
maintain homeostatic pH, what is the consequence of a pH
imbalance
Ans: Proteins contain many acidic and basic group that can be affected
by pH changes. Any increase or decrease in blood pH can alter the
structure of the protein (denature), thereby affecting its function as well
© 2025 All rights reserved
, 3 | Page
Describe the laboratory findings associated with metabolic
acidosis, metabolic alkalosis, respiratory acidosis and respiratory
alkalosis. (ie relative pH and CO2 levels).
Ans: Normal ABGs (Arterial Blood Gases) Blood pH: 7.35-7.45 PCO2: 35-
45 mm Hg PO2: 90-100 mm Hg HCO3-: 22-26 mEq/L SaO2: 95-100%
Respiratory acidosis and alkalosis are marked by changes in PCO2.
Higher = acidosis and lower = alkalosis
Metabolic acidosis and alkalosis are caused by something other than
abnormal CO2 levels. This could include toxicity, diabetes, renal failure
or excessive GI losses.
Here are the rules to follow to determine if is respiratory or metabolic in
nature. -If pH and PCO2 are moving in opposite directions, then it is the
pCO2 levels that are causing the imbalance and it is respiratory in
nature.
-If PCO2 is normal or is moving in the same direction as the pH, then the
imbalance is metabolic in nature.
The anion gap is the difference between measured cations (Na+
and K+) and measured anions (Cl- and HCO3-), this calculation can
be useful in determining the cause of metabolic acidosis.
Why would an increased anion gap be observed in diabetic
ketoacidosis or lactic acidosis?
Ans: The anion gap is the calculation of unmeasured anions in the
blood.
Lactic acid and ketones both lead to the production of unmeasured
anions, which remove HCO3- (a measured anion) due to buffering of the
excess H+ and therefore leads to an increase in the AG.
© 2025 All rights reserved
, 4 | Page
Why is it important to maintain a homeostatic balance of glucose
in the blood (ie describe the pathogenesis of diabetes)?
Ans: Insulin is the hormone responsible for initiating the uptake of
glucose by the cells. Cells use glucose to produce energy (ATP).
In a normal individual, when blood glucose increases, the pancreas is
signaled to produced in insulin, which binds to insulin receptors on a
cells surface and initiates the uptake of glucose.
Glucose is a very reactive molecule and if left in the blood, it can start to
bind to other proteins and lipids, which can lead to loss of function.
AGEs are advanced glycation end products that are a result of glucose
reacting with the endothelial lining, which can lead to damage in the
heart and kidneys.
Compare and contrast Type I and Type II Diabetes
Ans: Type I diabetes is caused by lack of insulin. With out insulin
signaling, glucose will not be taken into the cell and leads to high blood
glucose (hyperglycemia). Type I is usually treated with insulin injections.
Type II diabetes is caused by a desensitization to insulin signaling. The
insulin receptors are no longer responding to insulin, which also leads to
hyperglycemia.
Type II is usually treated with drugs to increase the sensitization to
insulin (metformin), dietary and life-style changes or insulin injections.
Describe some reasons for a patient needing dialysis
© 2025 All rights reserved
