WGU D236 PATHOPHYSIOLOGY EXAM | UPDATED
ACTUAL | COMPLETE QUESTIONS AND CORRECT
VERIFIED ANSWERS
• 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.
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.
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. 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 -✓✓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.
ACTUAL | COMPLETE QUESTIONS AND CORRECT
VERIFIED ANSWERS
• 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.
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.
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. 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 -✓✓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.
