WGU D236 PATHOPHYSIOLOGY OA AND
PRE-ASSESSMENT QUESTIONS AND
ANSWERS COMPLETE EXAM PREP
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Updated Questions and Answers
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,What is Starling's Law of Capillary Starling's Law describes how fluids move across the
forces? capillary membrane. There are two major opposing
forces that act to balance each other, hydrostatic
How does this explain why a pressure (pushing water out of the capillaries) and
nutritionally deficient child would have osmotic pressure (including oncontic pressure, which
edema? 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- A drop in blood pressure is sensed by the kidneys by
Angiotensin-Aldosterone System) low perfusion, which in turn begins to secrete renin.
result in increased blood volume and
increased blood pressure? 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 Normal levels of potassium are between 3.5 and 5.2
arrest? 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 Proteins contain many acidic and basic group that can
System, Phosphate Buffering System, be affected by pH changes. Any increase or decrease
and Carbonic Acid-Bicarbonate in blood pH can alter the structure of the protein
System to regulate and maintain (denature), thereby affecting its function as well
homeostatic pH, what is the
consequence of a pH imbalance
, Describe the laboratory findings Normal ABGs (Arterial Blood Gases) Blood pH: 7.35-
associated with metabolic acidosis, 7.45 PCO2: 35-45 mm Hg PO2: 90-100 mm Hg HCO3-:
metabolic alkalosis, respiratory 22-26 mEq/L SaO2: 95-100%
acidosis and respiratory alkalosis. (ie
relative pH and CO2 levels). 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 The anion gap is the calculation of unmeasured anions
between measured cations (Na+ and in the blood.
K+) and measured anions (Cl- and
HCO3-), this calculation can be useful Lactic acid and ketones both lead to the production
in determining the cause of metabolic of unmeasured anions, which remove HCO3- (a
acidosis. measured anion) due to buffering of the excess H+
and therefore leads to an increase in the AG.
Why would an increased anion gap be
observed in diabetic ketoacidosis or
lactic acidosis?
PRE-ASSESSMENT QUESTIONS AND
ANSWERS COMPLETE EXAM PREP
STUDY GUIDE
| GRADED A+ | GUARANTEED SUCCESS
Updated Questions and Answers
100% Verified Exam Prep
,What is Starling's Law of Capillary Starling's Law describes how fluids move across the
forces? capillary membrane. There are two major opposing
forces that act to balance each other, hydrostatic
How does this explain why a pressure (pushing water out of the capillaries) and
nutritionally deficient child would have osmotic pressure (including oncontic pressure, which
edema? 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- A drop in blood pressure is sensed by the kidneys by
Angiotensin-Aldosterone System) low perfusion, which in turn begins to secrete renin.
result in increased blood volume and
increased blood pressure? 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 Normal levels of potassium are between 3.5 and 5.2
arrest? 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 Proteins contain many acidic and basic group that can
System, Phosphate Buffering System, be affected by pH changes. Any increase or decrease
and Carbonic Acid-Bicarbonate in blood pH can alter the structure of the protein
System to regulate and maintain (denature), thereby affecting its function as well
homeostatic pH, what is the
consequence of a pH imbalance
, Describe the laboratory findings Normal ABGs (Arterial Blood Gases) Blood pH: 7.35-
associated with metabolic acidosis, 7.45 PCO2: 35-45 mm Hg PO2: 90-100 mm Hg HCO3-:
metabolic alkalosis, respiratory 22-26 mEq/L SaO2: 95-100%
acidosis and respiratory alkalosis. (ie
relative pH and CO2 levels). 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 The anion gap is the calculation of unmeasured anions
between measured cations (Na+ and in the blood.
K+) and measured anions (Cl- and
HCO3-), this calculation can be useful Lactic acid and ketones both lead to the production
in determining the cause of metabolic of unmeasured anions, which remove HCO3- (a
acidosis. measured anion) due to buffering of the excess H+
and therefore leads to an increase in the AG.
Why would an increased anion gap be
observed in diabetic ketoacidosis or
lactic acidosis?
