D236 OA WGU PATHOPHYSIOLOGY EXAM 2025
WITH DETAILED AND WELL EXPLAINED
ANSWERS/ COMPREHENSIVE
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.
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.
WITH DETAILED AND WELL EXPLAINED
ANSWERS/ COMPREHENSIVE
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.
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.
