WGU pathophysiology D236 Exam Questions
with Verified Solutions 2023-2024 Update.
What is Starling's Law of Capillary forces?
How does this explain why a nutritionally deficient child would have edema?
- Answer- 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 oncotic pressure, which pushes fluid into
the capillaries).
Both electrolytes and proteins (oncotic 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?
- Answer- 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?
- Answer- Normal levels of potassium are between 3.5 and 5.2 mEq/dL. Hyperkalemia refers to
potassium levels higher that 5.2 mEq/dL.
, WGU pathophysiology D236 Exam Questions
with Verified Solutions 2023-2024 Update.
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
- Answer- 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
Describe the laboratory findings associated with metabolic acidosis, metabolic alkalosis,
respiratory acidosis and respiratory alkalosis. (ie relative pH and CO2 levels).
- Answer- 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.
, WGU pathophysiology D236 Exam Questions
with Verified Solutions 2023-2024 Update.
Why would an increased anion gap be observed in diabetic ketoacidosis or lactic acidosis?
- Answer- 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.
Why is it important to maintain a homeostatic balance of glucose in the blood (ie describe the
pathogenesis of diabetes)?
- Answer- 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
- Answer- Type I diabetes is caused by lack of insulin. Without 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.
, WGU pathophysiology D236 Exam Questions
with Verified Solutions 2023-2024 Update.
Describe some reasons for a patient needing dialysis
- Answer- AEIOU-acidosis. Electrolytes, Intoxication/Ingestion, overload, uremia. Patients with
kidney or heart failure.
A build up of phosphates, urea and magnesium are removed from the blood using a semi-
permeable membrane and dialysate.
AEIOU:
A—acidosis;
E—electrolytes principally hyperkalemia;
I—ingestions or overdose of medications/drugs;
O—overload of fluid causing heart failure;
U—uremia leading to encephalitis/pericarditis
Compare and contrast hemodialysis and peritoneal dialysis.
What are some reasons for a patient choosing one over the other?
- Answer- Hemodialysis uses a machine to pump blood from the body in one tube while
dialysate (made of water, electrolytes and salts) is pumped in the separate tube in the opposite
direction. Waste from the blood diffuses through the semipermeable membrane separating the
blood from the dialysate.
Peritoneal Dialysis does not use a machine, but instead injects a solution of water and glucose
into the abdominal cavity. The peritoneum acts as the membrane instead of dialysis tubing. The
waste products diffuse into the abdominal cavity and the waste solution is then drained from
the body.
Peritoneal dialysis offers continuous filtration and is less disruption to the patient's daily
routines. However, it does require some training of the patient and is not recommended for
individuals who are overweight or have severe kidney failure.
with Verified Solutions 2023-2024 Update.
What is Starling's Law of Capillary forces?
How does this explain why a nutritionally deficient child would have edema?
- Answer- 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 oncotic pressure, which pushes fluid into
the capillaries).
Both electrolytes and proteins (oncotic 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?
- Answer- 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?
- Answer- Normal levels of potassium are between 3.5 and 5.2 mEq/dL. Hyperkalemia refers to
potassium levels higher that 5.2 mEq/dL.
, WGU pathophysiology D236 Exam Questions
with Verified Solutions 2023-2024 Update.
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
- Answer- 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
Describe the laboratory findings associated with metabolic acidosis, metabolic alkalosis,
respiratory acidosis and respiratory alkalosis. (ie relative pH and CO2 levels).
- Answer- 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.
, WGU pathophysiology D236 Exam Questions
with Verified Solutions 2023-2024 Update.
Why would an increased anion gap be observed in diabetic ketoacidosis or lactic acidosis?
- Answer- 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.
Why is it important to maintain a homeostatic balance of glucose in the blood (ie describe the
pathogenesis of diabetes)?
- Answer- 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
- Answer- Type I diabetes is caused by lack of insulin. Without 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.
, WGU pathophysiology D236 Exam Questions
with Verified Solutions 2023-2024 Update.
Describe some reasons for a patient needing dialysis
- Answer- AEIOU-acidosis. Electrolytes, Intoxication/Ingestion, overload, uremia. Patients with
kidney or heart failure.
A build up of phosphates, urea and magnesium are removed from the blood using a semi-
permeable membrane and dialysate.
AEIOU:
A—acidosis;
E—electrolytes principally hyperkalemia;
I—ingestions or overdose of medications/drugs;
O—overload of fluid causing heart failure;
U—uremia leading to encephalitis/pericarditis
Compare and contrast hemodialysis and peritoneal dialysis.
What are some reasons for a patient choosing one over the other?
- Answer- Hemodialysis uses a machine to pump blood from the body in one tube while
dialysate (made of water, electrolytes and salts) is pumped in the separate tube in the opposite
direction. Waste from the blood diffuses through the semipermeable membrane separating the
blood from the dialysate.
Peritoneal Dialysis does not use a machine, but instead injects a solution of water and glucose
into the abdominal cavity. The peritoneum acts as the membrane instead of dialysis tubing. The
waste products diffuse into the abdominal cavity and the waste solution is then drained from
the body.
Peritoneal dialysis offers continuous filtration and is less disruption to the patient's daily
routines. However, it does require some training of the patient and is not recommended for
individuals who are overweight or have severe kidney failure.
