WGU PATHOPHYSIOLOGY D236 EXAM
REVIEW GUIDE QUESTIONS WITH
COMPLETE SOLUTIONS
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 causes
muscle weakness 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 -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%
Metabolic acidosis ph less than 7.35 and low HC03. Metabolic alkolosis ph greater than
7.35 and so is hco3 both of these can be caused my dka. if the ph and pco2 levels are
going in the same direction it is metabolic if they are going in a different direction it is
respiratory
Respiratory alkolosis ph greater than 7.35and pco2 is decreased. repsiratory acidosis is
ph less than 7.35 and pco2 greater than
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 lead to the production of unmeasured anions, 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 if left in the blood, can to bind to proteins and lipids, which can lead to loss of
function. leading 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.
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 triggers prodcution of renin
Renin triggers the liver to produce angiotensinogen, and converts it into Angiotensin I
and angiotensin II by the enzyme
Angiotensin-converting enzyme (ACE). Angiotensin II stimulates peripheral arterial
vasoconstriction which raises BP.
, Angiotensin II stimulate the adrenal gland to release aldosterone, which acts to increase
sodium and water absorption increasing blood volume, while also increased potassium
secretion in urine.
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.
What are some reasons for a patient choosing one over the other? - ANSWER -
Hemodialysis uses a machine to pump blood from the body in one tube while dialysate
(made of water, electrolytes and salts) is pumped in the separate tube in the opposite
direction. Waste from the blood diffuses through the semipermeable membrane
separating the blood from the dialysate.
Peritoneal Dialysis does not use a machine, but instead injects a solution of water and
glucose into the abdominal cavity. The peritoneum acts as the membrane instead of
dialysis tubing. The waste products diffuse into the abdominal cavity and the waste
solution is then drained from the body.
Peritoneal dialysis offers continuous filtration and is less disruption to the patient's daily
routines. However, it does require some training of the patient and is not recommended
for individuals who are overweight or have severe kidney failure.
Hemodialysis provides medical care, but 3 times a week for several hours sitting at a
hospital or clinic. Individuals with acute kidney failure are recommended to use
hemodialysis.
How does homeostasis and maintaining optimal physiological health impact your
wellbeing? - ANSWER -Homeostasis acts to create a constant and stable environment
in the body despite internal and external changes. Proteins and other cellular processes
require optimal conditions in order to carry out their functions.
REVIEW GUIDE QUESTIONS WITH
COMPLETE SOLUTIONS
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 causes
muscle weakness 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 -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%
Metabolic acidosis ph less than 7.35 and low HC03. Metabolic alkolosis ph greater than
7.35 and so is hco3 both of these can be caused my dka. if the ph and pco2 levels are
going in the same direction it is metabolic if they are going in a different direction it is
respiratory
Respiratory alkolosis ph greater than 7.35and pco2 is decreased. repsiratory acidosis is
ph less than 7.35 and pco2 greater than
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 lead to the production of unmeasured anions, 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 if left in the blood, can to bind to proteins and lipids, which can lead to loss of
function. leading 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.
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 triggers prodcution of renin
Renin triggers the liver to produce angiotensinogen, and converts it into Angiotensin I
and angiotensin II by the enzyme
Angiotensin-converting enzyme (ACE). Angiotensin II stimulates peripheral arterial
vasoconstriction which raises BP.
, Angiotensin II stimulate the adrenal gland to release aldosterone, which acts to increase
sodium and water absorption increasing blood volume, while also increased potassium
secretion in urine.
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.
What are some reasons for a patient choosing one over the other? - ANSWER -
Hemodialysis uses a machine to pump blood from the body in one tube while dialysate
(made of water, electrolytes and salts) is pumped in the separate tube in the opposite
direction. Waste from the blood diffuses through the semipermeable membrane
separating the blood from the dialysate.
Peritoneal Dialysis does not use a machine, but instead injects a solution of water and
glucose into the abdominal cavity. The peritoneum acts as the membrane instead of
dialysis tubing. The waste products diffuse into the abdominal cavity and the waste
solution is then drained from the body.
Peritoneal dialysis offers continuous filtration and is less disruption to the patient's daily
routines. However, it does require some training of the patient and is not recommended
for individuals who are overweight or have severe kidney failure.
Hemodialysis provides medical care, but 3 times a week for several hours sitting at a
hospital or clinic. Individuals with acute kidney failure are recommended to use
hemodialysis.
How does homeostasis and maintaining optimal physiological health impact your
wellbeing? - ANSWER -Homeostasis acts to create a constant and stable environment
in the body despite internal and external changes. Proteins and other cellular processes
require optimal conditions in order to carry out their functions.
