WGU pathophysiology
D236
1. What is Starling's Law of Capillary forces?
How does this explain why a nutritionally deficient child would have edema?-
: 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 pres- sure, 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 nutri- tionally deficient child) would cause wa
to leave the capillaries and enter the cells and interstitial fluid which can lead to edema.
2. How does the RAAS (Renin-Angiotensin-Aldosterone System) result in in- creased blood volume and increased
blood pressure?: 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.
3. How can hyperkalemia lead to cardiac arrest?: 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 mu
can cause muscle spasms.
This is especially dangerous in the heart muscle and an irregular heartbeat can cause a heart attack
, WGU pathophysiology
D236
4. 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: 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
5. Describe the laboratory findings associated with metabolic acidosis, meta- bolic alkalosis, respiratory acidosis
and respiratory alkalosis. (ie relative pH and CO2 levels).: 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.
6. Theanion gap is the difference between measured cations (Na+ and K+) and measured anions (Cl- and
HCO3-), this calculation can be useful in determin- ing the cause of metabolic acidosis.
Why would an increased anion gap be observed in diabetic ketoacidosis or lactic acidosis?: 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
buffering of the excess H+ and therefore leads to an increase in the AG.
7. Why is it important to maintain a homeostatic balance of glucose in the blood (ie describe the pathogenesis
of diabetes)?: Insulin is the hormone re- sponsible for initiating the uptake of glucose by the cells. Cells use glucose
to produce energy (ATP).
, WGU pathophysiology
D236
In a normal individual, when blood glucose increases, the pancreas is signaled to produced in insulin, which binds to insu
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
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.
8. Compare and contrast Type I and Type II Diabetes: 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 (met- formin), dietary and life-style changes o
insulin injections.
9. Describe some reasons for a patient needing dialysis: AEIOU-acidosis. Elec- trolytes, Intoxication/Ingestion,
overload, uremia. Patients with kidney or heart fail- ure.
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
10.Compare and contrast hemodialysis and peritoneal dialysis.
What are some reasons for a patient choosing one over the other?: Hemodial- ysis 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.
, WGU pathophysiology
D236
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 an
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 requi
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.
11.How does homeostasis and maintaining optimal physiological health im- pact your wellbeing?: Homeostasis
acts to create a constant and stable environ- ment in the body despite internal and external changes. Proteins and other
cellular processes require optimal conditions in order to carry out their functions.
Alterations in pH, salt concentration, temperature, glucose levels, etc. can have negative effects on health, so it is vital
for mechanisms that regulate homeostasis to function properly for maintaining good health
12.Differentiate between Innate Immunity and Adaptive Immunity ?: The innate immune system encompasses
physical barriers and chemical and cellular defenses. Physical barriers protect the body from invasion. These include
things like the skin and eyelashes. Chemical barriers are defense mechanisms that can destroy harmful agent. Examples
include tears, mucous, and stomach acid.
Cellular defenses of the innate immune response are non-specific. These cellular defenses identify pathogens and
substances that are potentially dangerous and takes steps to neutralize or destroy them.
Adaptive immunity is an organism's acquired immunity to a specific pathogen. As such, it's also referred to as acquired
immunity. Adaptive immunity is not immediate, nor does it always last throughout an organism's entire lifespan, although
can.
The adaptive immune response is marked by clonal expansion of T and B lympho- cytes, releasing many antibody copies
neutralize or destroy their target antigen
13.What is a way that Adaptive Immunity can recruit innate immunity?: The innate immune response to
microbes stimulates adaptive immune responses and
D236
1. What is Starling's Law of Capillary forces?
How does this explain why a nutritionally deficient child would have edema?-
: 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 pres- sure, 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 nutri- tionally deficient child) would cause wa
to leave the capillaries and enter the cells and interstitial fluid which can lead to edema.
2. How does the RAAS (Renin-Angiotensin-Aldosterone System) result in in- creased blood volume and increased
blood pressure?: 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.
3. How can hyperkalemia lead to cardiac arrest?: 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 mu
can cause muscle spasms.
This is especially dangerous in the heart muscle and an irregular heartbeat can cause a heart attack
, WGU pathophysiology
D236
4. 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: 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
5. Describe the laboratory findings associated with metabolic acidosis, meta- bolic alkalosis, respiratory acidosis
and respiratory alkalosis. (ie relative pH and CO2 levels).: 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.
6. Theanion gap is the difference between measured cations (Na+ and K+) and measured anions (Cl- and
HCO3-), this calculation can be useful in determin- ing the cause of metabolic acidosis.
Why would an increased anion gap be observed in diabetic ketoacidosis or lactic acidosis?: 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
buffering of the excess H+ and therefore leads to an increase in the AG.
7. Why is it important to maintain a homeostatic balance of glucose in the blood (ie describe the pathogenesis
of diabetes)?: Insulin is the hormone re- sponsible for initiating the uptake of glucose by the cells. Cells use glucose
to produce energy (ATP).
, WGU pathophysiology
D236
In a normal individual, when blood glucose increases, the pancreas is signaled to produced in insulin, which binds to insu
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
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.
8. Compare and contrast Type I and Type II Diabetes: 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 (met- formin), dietary and life-style changes o
insulin injections.
9. Describe some reasons for a patient needing dialysis: AEIOU-acidosis. Elec- trolytes, Intoxication/Ingestion,
overload, uremia. Patients with kidney or heart fail- ure.
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
10.Compare and contrast hemodialysis and peritoneal dialysis.
What are some reasons for a patient choosing one over the other?: Hemodial- ysis 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.
, WGU pathophysiology
D236
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 an
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 requi
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.
11.How does homeostasis and maintaining optimal physiological health im- pact your wellbeing?: Homeostasis
acts to create a constant and stable environ- ment in the body despite internal and external changes. Proteins and other
cellular processes require optimal conditions in order to carry out their functions.
Alterations in pH, salt concentration, temperature, glucose levels, etc. can have negative effects on health, so it is vital
for mechanisms that regulate homeostasis to function properly for maintaining good health
12.Differentiate between Innate Immunity and Adaptive Immunity ?: The innate immune system encompasses
physical barriers and chemical and cellular defenses. Physical barriers protect the body from invasion. These include
things like the skin and eyelashes. Chemical barriers are defense mechanisms that can destroy harmful agent. Examples
include tears, mucous, and stomach acid.
Cellular defenses of the innate immune response are non-specific. These cellular defenses identify pathogens and
substances that are potentially dangerous and takes steps to neutralize or destroy them.
Adaptive immunity is an organism's acquired immunity to a specific pathogen. As such, it's also referred to as acquired
immunity. Adaptive immunity is not immediate, nor does it always last throughout an organism's entire lifespan, although
can.
The adaptive immune response is marked by clonal expansion of T and B lympho- cytes, releasing many antibody copies
neutralize or destroy their target antigen
13.What is a way that Adaptive Immunity can recruit innate immunity?: The innate immune response to
microbes stimulates adaptive immune responses and
