ne
tz
sh
ne
WGU pathophysiology D236-Exam
la
tz
sh
Sp
Questions and Answers
ne
la
tz
sh
Sp
What is Starling's Law of Capillary forces?
ne
How does this explain why a nutritionally deficient child would have edema? - ANSWER
la
tz
Starling's Law describes how fluids move across the capillary membrane. There are two
sh
major opposing forces that act to balance each other, hydrostatic pressure (pushing
Sp
ne
water out of the capillaries) and osmotic pressure (including oncontic pressure, which
pushes fluid into the capillaries).
la
tz
sh
Both electrolytes and proteins (oncontic pressure) in the blood affect osmotic pressure,
Sp
high electrolyte and protein concentrations in the blood would cause water to leave the
ne
cells and interstitial space and enter the blood stream to dilute the high concentrations.
la
tz
sh
On, the other hand, low electrolyte and protein concentrations (as seen in a nutritionally
Sp
deficient child) would cause water to leave the capillaries and enter the cells and
ne
interstitial fluid which can lead to edema.
la
tz
sh
How does the RAAS (Renin-Angiotensin-Aldosterone System) result in increased blood
Sp
volume and increased blood pressure? - ANSWER A drop in blood pressure is sensed
ne
by the kidneys by low perfusion, which in turn begins to secrete renin.
la
tz
sh
Renin then triggers the liver to produce angiotensinogen, which is converted to
Sp
Angiotensin I in the lungs and then angiotensin II by the enzyme
ne
la
Angiotensin-converting enzyme (ACE). Angiotensin II stimulates peripheral arterial
vasoconstriction which raises BP.
tz
sh
Sp
ne
Angiotensin II is also stimulating the adrenal gland to release aldosterone, which acts to
la
increase sodium and water reabsorption increasing blood volume, while also increased
tz
potassium secretion in urine.
sh
Sp
ne
How can hyperkalemia lead to cardiac arrest? - ANSWER Normal levels of potassium
la
are between 3.5 and 5.2 mEq/dL. Hyperkalemia refers to potassium levels higher that
tz
5.2 mEq/dL.
sh
Sp
ne
A major function of potassium is to conduct nerve impulses in muscles. Too low and
la
muscle weakness occurs and too much can cause muscle spasms.
tz
sh
Sp
This is especially dangerous in the heart muscle and an irregular heartbeat can cause a
ne
heart attack
la
sh
Sp
la
Sp
, ne
tz
sh
ne
la
The body uses the Protein Buffering System, Phosphate Buffering System, and
tz
Carbonic Acid-Bicarbonate System to regulate and maintain homeostatic pH, what is
sh
Sp
the consequence of a pH imbalance - ANSWER Proteins contain many acidic and basic
ne
group that can be affected by pH changes. Any increase or decrease in blood pH can
la
alter the structure of the protein (denature), thereby affecting its function as well
tz
sh
Sp
Describe the laboratory findings associated with metabolic acidosis, metabolic alkalosis,
ne
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
la
tz
Hg PO2: 90-100 mm Hg HCO3-: 22-26 mEq/L SaO2: 95-100%
sh
Sp
ne
Respiratory acidosis and alkalosis are marked by changes in PCO2. Higher = acidosis
and lower = alkalosis
la
tz
sh
Metabolic acidosis and alkalosis are caused by something other than abnormal CO2
Sp
levels. This could include toxicity, diabetes, renal failure or excessive GI losses.
ne
la
Here are the rules to follow to determine if is respiratory or metabolic in nature. -If pH
tz
sh
and PCO2 are moving in opposite directions, then it is the pCO2 levels that are causing
Sp
the imbalance and it is respiratory in nature.
ne
la
-If PCO2 is normal or is moving in the same direction as the pH, then the imbalance is
tz
sh
metabolic in nature.
Sp
ne
The anion gap is the difference between measured cations (Na+ and K+) and measured
la
anions (Cl- and HCO3-), this calculation can be useful in determining the cause of
tz
metabolic acidosis.
sh
Sp
ne
Why would an increased anion gap be observed in diabetic ketoacidosis or lactic
la
acidosis? - ANSWER The anion gap is the calculation of unmeasured anions in the
blood.
tz
sh
Sp
ne
Lactic acid and ketones both lead to the production of unmeasured anions, which
la
remove HCO3- (a measured anion) due to buffering of the excess H+ and therefore
tz
leads to an increase in the AG.
sh
Sp
ne
Why is it important to maintain a homeostatic balance of glucose in the blood (ie
la
describe the pathogenesis of diabetes)? - ANSWER Insulin is the hormone responsible
tz
for initiating the uptake of glucose by the cells. Cells use glucose to produce energy
sh
Sp
(ATP).
ne
la
In a normal individual, when blood glucose increases, the pancreas is signaled to
tz
produced in insulin, which binds to insulin receptors on a cells surface and initiates the
sh
Sp
uptake of glucose.
ne
la
sh
Sp
la
Sp
, ne
tz
sh
ne
Glucose is a very reactive molecule and if left in the blood, it can start to bind to other
la
proteins and lipids, which can lead to loss of function.
tz
sh
Sp
AGEs are advanced glycation end products that are a result of glucose reacting with the
ne
endothelial lining, which can lead to damage in the heart and kidneys.
la
tz
Compare and contrast Type I and Type II Diabetes - ANSWER Type I diabetes is
sh
Sp
caused by lack of insulin. With out insulin signaling, glucose will not be taken into the
ne
cell and leads to high blood glucose (hyperglycemia). Type I is usually treated with
insulin injections.
la
tz
sh
Type II diabetes is caused by a desensitization to insulin signaling. The insulin receptors
Sp
ne
are no longer responding to insulin, which also leads to hyperglycemia.
la
Type II is usually treated with drugs to increase the sensitization to insulin (metformin),
tz
sh
dietary and life-style changes or insulin injections.
Sp
ne
Describe some reasons for a patient needing dialysis - ANSWER AEIOU-acidosis.
la
Electrolytes, Intoxication/Ingestion, overload, uremia. Patients with kidney or heart
tz
sh
failure.
Sp
ne
A build up of phosphates, urea and magnesium are removed from the blood using a
la
semi-permeable membrane and dialysate.
tz
sh
Sp
AEIOU:
ne
A—acidosis;
la
E—electrolytes principally hyperkalemia;
tz
I—ingestions or overdose of medications/drugs;
sh
Sp
O—overload of fluid causing heart failure;
ne
U—uremia leading to encephalitis/pericarditis
la
Compare and contrast hemodialysis and peritoneal dialysis.
tz
sh
Sp
ne
What are some reasons for a patient choosing one over the other? - ANSWER
la
Hemodialysis uses a machine to pump blood from the body in one tube while dialysate
tz
(made of water, electrolytes and salts) is pumped in the separate tube in the opposite
sh
Sp
direction. Waste from the blood diffuses through the semipermeable membrane
ne
separating the blood from the dialysate.
la
tz
Peritoneal Dialysis does not use a machine, but instead injects a solution of water and
sh
Sp
glucose into the abdominal cavity. The peritoneum acts as the membrane instead of
ne
dialysis tubing. The waste products diffuse into the abdominal cavity and the waste
la
solution is then drained from the body.
tz
sh
Sp
ne
la
sh
Sp
la
Sp
, ne
tz
sh
ne
Peritoneal dialysis offers continuous filtration and is less disruption to the patient's daily
la
routines. However, it does require some training of the patient and is not recommended
tz
for individuals who are overweight or have severe kidney failure.
sh
Sp
ne
Hemodialysis provides medical care, but 3 times a week for several hours sitting at a
la
hospital or clinic. Individuals with acute kidney failure are recommended to use
tz
hemodialysis.
sh
Sp
ne
How does homeostasis and maintaining optimal physiological health impact your
wellbeing? - ANSWER Homeostasis acts to create a constant and stable environment in
la
tz
the body despite internal and external changes. Proteins and other cellular processes
sh
require optimal conditions in order to carry out their functions.
Sp
ne
Alterations in pH, salt concentration, temperature, glucose levels, etc. can have
la
negative effects on health, so it is vital for mechanisms that regulate homeostasis to
tz
sh
function properly for maintaining good health
Sp
ne
Differentiate between Innate Immunity and Adaptive Immunity ? - ANSWER The innate
la
immune system encompasses physical barriers and chemical and cellular defenses.
tz
sh
Physical barriers protect the body from invasion. These include things like the skin and
Sp
eyelashes. Chemical barriers are defense mechanisms that can destroy harmful agent.
ne
Examples include tears, mucous, and stomach acid.
la
tz
sh
Cellular defenses of the innate immune response are non-specific. These cellular
Sp
defenses identify pathogens and substances that are potentially dangerous and takes
ne
steps to neutralize or destroy them.
la
tz
sh
Adaptive immunity is an organism's acquired immunity to a specific pathogen. As such,
Sp
it's also referred to as acquired immunity. Adaptive immunity is not immediate, nor does
ne
it always last throughout an organism's entire lifespan, although it can.
la
tz
The adaptive immune response is marked by clonal expansion of T and B lymphocytes,
sh
Sp
releasing many antibody copies to neutralize or destroy their target antigen
ne
la
What is a way that Adaptive Immunity can recruit innate immunity? - ANSWER The
tz
innate immune response to microbes stimulates adaptive immune responses and
sh
Sp
influences the nature of the adaptive responses.
ne
la
Conversely, adaptive immune responses often work by enhancing the protective
tz
mechanisms of innate immunity, making them more capable of effectively combating
sh
Sp
pathogenic microbes
ne
la
Why are some infections harder on children while other infections are harder on the
tz
elderly? - ANSWER Children have not been exposed to many pathogens yet, so they
sh
Sp
lack memory cells and have not built-up immunity yet.
ne
la
sh
Sp
la
Sp
tz
sh
ne
WGU pathophysiology D236-Exam
la
tz
sh
Sp
Questions and Answers
ne
la
tz
sh
Sp
What is Starling's Law of Capillary forces?
ne
How does this explain why a nutritionally deficient child would have edema? - ANSWER
la
tz
Starling's Law describes how fluids move across the capillary membrane. There are two
sh
major opposing forces that act to balance each other, hydrostatic pressure (pushing
Sp
ne
water out of the capillaries) and osmotic pressure (including oncontic pressure, which
pushes fluid into the capillaries).
la
tz
sh
Both electrolytes and proteins (oncontic pressure) in the blood affect osmotic pressure,
Sp
high electrolyte and protein concentrations in the blood would cause water to leave the
ne
cells and interstitial space and enter the blood stream to dilute the high concentrations.
la
tz
sh
On, the other hand, low electrolyte and protein concentrations (as seen in a nutritionally
Sp
deficient child) would cause water to leave the capillaries and enter the cells and
ne
interstitial fluid which can lead to edema.
la
tz
sh
How does the RAAS (Renin-Angiotensin-Aldosterone System) result in increased blood
Sp
volume and increased blood pressure? - ANSWER A drop in blood pressure is sensed
ne
by the kidneys by low perfusion, which in turn begins to secrete renin.
la
tz
sh
Renin then triggers the liver to produce angiotensinogen, which is converted to
Sp
Angiotensin I in the lungs and then angiotensin II by the enzyme
ne
la
Angiotensin-converting enzyme (ACE). Angiotensin II stimulates peripheral arterial
vasoconstriction which raises BP.
tz
sh
Sp
ne
Angiotensin II is also stimulating the adrenal gland to release aldosterone, which acts to
la
increase sodium and water reabsorption increasing blood volume, while also increased
tz
potassium secretion in urine.
sh
Sp
ne
How can hyperkalemia lead to cardiac arrest? - ANSWER Normal levels of potassium
la
are between 3.5 and 5.2 mEq/dL. Hyperkalemia refers to potassium levels higher that
tz
5.2 mEq/dL.
sh
Sp
ne
A major function of potassium is to conduct nerve impulses in muscles. Too low and
la
muscle weakness occurs and too much can cause muscle spasms.
tz
sh
Sp
This is especially dangerous in the heart muscle and an irregular heartbeat can cause a
ne
heart attack
la
sh
Sp
la
Sp
, ne
tz
sh
ne
la
The body uses the Protein Buffering System, Phosphate Buffering System, and
tz
Carbonic Acid-Bicarbonate System to regulate and maintain homeostatic pH, what is
sh
Sp
the consequence of a pH imbalance - ANSWER Proteins contain many acidic and basic
ne
group that can be affected by pH changes. Any increase or decrease in blood pH can
la
alter the structure of the protein (denature), thereby affecting its function as well
tz
sh
Sp
Describe the laboratory findings associated with metabolic acidosis, metabolic alkalosis,
ne
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
la
tz
Hg PO2: 90-100 mm Hg HCO3-: 22-26 mEq/L SaO2: 95-100%
sh
Sp
ne
Respiratory acidosis and alkalosis are marked by changes in PCO2. Higher = acidosis
and lower = alkalosis
la
tz
sh
Metabolic acidosis and alkalosis are caused by something other than abnormal CO2
Sp
levels. This could include toxicity, diabetes, renal failure or excessive GI losses.
ne
la
Here are the rules to follow to determine if is respiratory or metabolic in nature. -If pH
tz
sh
and PCO2 are moving in opposite directions, then it is the pCO2 levels that are causing
Sp
the imbalance and it is respiratory in nature.
ne
la
-If PCO2 is normal or is moving in the same direction as the pH, then the imbalance is
tz
sh
metabolic in nature.
Sp
ne
The anion gap is the difference between measured cations (Na+ and K+) and measured
la
anions (Cl- and HCO3-), this calculation can be useful in determining the cause of
tz
metabolic acidosis.
sh
Sp
ne
Why would an increased anion gap be observed in diabetic ketoacidosis or lactic
la
acidosis? - ANSWER The anion gap is the calculation of unmeasured anions in the
blood.
tz
sh
Sp
ne
Lactic acid and ketones both lead to the production of unmeasured anions, which
la
remove HCO3- (a measured anion) due to buffering of the excess H+ and therefore
tz
leads to an increase in the AG.
sh
Sp
ne
Why is it important to maintain a homeostatic balance of glucose in the blood (ie
la
describe the pathogenesis of diabetes)? - ANSWER Insulin is the hormone responsible
tz
for initiating the uptake of glucose by the cells. Cells use glucose to produce energy
sh
Sp
(ATP).
ne
la
In a normal individual, when blood glucose increases, the pancreas is signaled to
tz
produced in insulin, which binds to insulin receptors on a cells surface and initiates the
sh
Sp
uptake of glucose.
ne
la
sh
Sp
la
Sp
, ne
tz
sh
ne
Glucose is a very reactive molecule and if left in the blood, it can start to bind to other
la
proteins and lipids, which can lead to loss of function.
tz
sh
Sp
AGEs are advanced glycation end products that are a result of glucose reacting with the
ne
endothelial lining, which can lead to damage in the heart and kidneys.
la
tz
Compare and contrast Type I and Type II Diabetes - ANSWER Type I diabetes is
sh
Sp
caused by lack of insulin. With out insulin signaling, glucose will not be taken into the
ne
cell and leads to high blood glucose (hyperglycemia). Type I is usually treated with
insulin injections.
la
tz
sh
Type II diabetes is caused by a desensitization to insulin signaling. The insulin receptors
Sp
ne
are no longer responding to insulin, which also leads to hyperglycemia.
la
Type II is usually treated with drugs to increase the sensitization to insulin (metformin),
tz
sh
dietary and life-style changes or insulin injections.
Sp
ne
Describe some reasons for a patient needing dialysis - ANSWER AEIOU-acidosis.
la
Electrolytes, Intoxication/Ingestion, overload, uremia. Patients with kidney or heart
tz
sh
failure.
Sp
ne
A build up of phosphates, urea and magnesium are removed from the blood using a
la
semi-permeable membrane and dialysate.
tz
sh
Sp
AEIOU:
ne
A—acidosis;
la
E—electrolytes principally hyperkalemia;
tz
I—ingestions or overdose of medications/drugs;
sh
Sp
O—overload of fluid causing heart failure;
ne
U—uremia leading to encephalitis/pericarditis
la
Compare and contrast hemodialysis and peritoneal dialysis.
tz
sh
Sp
ne
What are some reasons for a patient choosing one over the other? - ANSWER
la
Hemodialysis uses a machine to pump blood from the body in one tube while dialysate
tz
(made of water, electrolytes and salts) is pumped in the separate tube in the opposite
sh
Sp
direction. Waste from the blood diffuses through the semipermeable membrane
ne
separating the blood from the dialysate.
la
tz
Peritoneal Dialysis does not use a machine, but instead injects a solution of water and
sh
Sp
glucose into the abdominal cavity. The peritoneum acts as the membrane instead of
ne
dialysis tubing. The waste products diffuse into the abdominal cavity and the waste
la
solution is then drained from the body.
tz
sh
Sp
ne
la
sh
Sp
la
Sp
, ne
tz
sh
ne
Peritoneal dialysis offers continuous filtration and is less disruption to the patient's daily
la
routines. However, it does require some training of the patient and is not recommended
tz
for individuals who are overweight or have severe kidney failure.
sh
Sp
ne
Hemodialysis provides medical care, but 3 times a week for several hours sitting at a
la
hospital or clinic. Individuals with acute kidney failure are recommended to use
tz
hemodialysis.
sh
Sp
ne
How does homeostasis and maintaining optimal physiological health impact your
wellbeing? - ANSWER Homeostasis acts to create a constant and stable environment in
la
tz
the body despite internal and external changes. Proteins and other cellular processes
sh
require optimal conditions in order to carry out their functions.
Sp
ne
Alterations in pH, salt concentration, temperature, glucose levels, etc. can have
la
negative effects on health, so it is vital for mechanisms that regulate homeostasis to
tz
sh
function properly for maintaining good health
Sp
ne
Differentiate between Innate Immunity and Adaptive Immunity ? - ANSWER The innate
la
immune system encompasses physical barriers and chemical and cellular defenses.
tz
sh
Physical barriers protect the body from invasion. These include things like the skin and
Sp
eyelashes. Chemical barriers are defense mechanisms that can destroy harmful agent.
ne
Examples include tears, mucous, and stomach acid.
la
tz
sh
Cellular defenses of the innate immune response are non-specific. These cellular
Sp
defenses identify pathogens and substances that are potentially dangerous and takes
ne
steps to neutralize or destroy them.
la
tz
sh
Adaptive immunity is an organism's acquired immunity to a specific pathogen. As such,
Sp
it's also referred to as acquired immunity. Adaptive immunity is not immediate, nor does
ne
it always last throughout an organism's entire lifespan, although it can.
la
tz
The adaptive immune response is marked by clonal expansion of T and B lymphocytes,
sh
Sp
releasing many antibody copies to neutralize or destroy their target antigen
ne
la
What is a way that Adaptive Immunity can recruit innate immunity? - ANSWER The
tz
innate immune response to microbes stimulates adaptive immune responses and
sh
Sp
influences the nature of the adaptive responses.
ne
la
Conversely, adaptive immune responses often work by enhancing the protective
tz
mechanisms of innate immunity, making them more capable of effectively combating
sh
Sp
pathogenic microbes
ne
la
Why are some infections harder on children while other infections are harder on the
tz
elderly? - ANSWER Children have not been exposed to many pathogens yet, so they
sh
Sp
lack memory cells and have not built-up immunity yet.
ne
la
sh
Sp
la
Sp
