WGU D236 PATHOPHYSIOLOGY BANK
VERSION AND STUDY GUIDE | ACTUAL
EXAM QUESTIONS AND ANSWERS AND
RATIONALES | EXPERT VERIFIED FOR
GUARANTEED PASS | LATEST UPDATE
/BRAND NEW
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
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? - 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.
VERSION AND STUDY GUIDE | ACTUAL
EXAM QUESTIONS AND ANSWERS AND
RATIONALES | EXPERT VERIFIED FOR
GUARANTEED PASS | LATEST UPDATE
/BRAND NEW
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
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? - 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.
