NURSING 476
Pathophysiology
Midterm Exam Review
2024
,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 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.
2.How does the RAAS (Renin-Angiotensin-
Aldosterone System) result in increased 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 much can cause muscle spasms. This is
especially dangerous in the heart muscle and an irregular heartbeat can cause
a heart attack.
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, metabolic 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 tin the same direction as
the pH, then the imbalance is metabolic in nature.
6. 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?
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.
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 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 is a very reactive molecule and if left in the blood, it can start
to bind to other proteins and lipids, which can lead to 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 (metformin), dietary and life-style changes or insulin injections.
9. Describe some reasons for a patient needing
dialysis 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.
10. Compare and contrast hemodialysis and
peritoneal dialysis. What are some reasons for a
patient choosing one over the other?
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 hemo
11.Essential Question: How does homeostasis and
maintaining optimal physiological health impact
your wellbeing?
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.
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.
Lesson 2: Cellular Response
and Adaptation
1. 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 it
can. The adaptive immune response is marked by clonal expansion of T and B
lymphocytes, releasing many antibody copies to neutralize or destroy their
target antigen.
2. What is a way that Adaptive Immunity can
recruit innate immunity?
The innate immune response to microbes stimulates adaptive immune
responses and influences the nature of the adaptive responses. Conversely,
adaptive immune
Pathophysiology
Midterm Exam Review
2024
,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 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.
2.How does the RAAS (Renin-Angiotensin-
Aldosterone System) result in increased 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 much can cause muscle spasms. This is
especially dangerous in the heart muscle and an irregular heartbeat can cause
a heart attack.
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, metabolic 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 tin the same direction as
the pH, then the imbalance is metabolic in nature.
6. 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?
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.
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 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 is a very reactive molecule and if left in the blood, it can start
to bind to other proteins and lipids, which can lead to 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 (metformin), dietary and life-style changes or insulin injections.
9. Describe some reasons for a patient needing
dialysis 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.
10. Compare and contrast hemodialysis and
peritoneal dialysis. What are some reasons for a
patient choosing one over the other?
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 hemo
11.Essential Question: How does homeostasis and
maintaining optimal physiological health impact
your wellbeing?
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.
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.
Lesson 2: Cellular Response
and Adaptation
1. 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 it
can. The adaptive immune response is marked by clonal expansion of T and B
lymphocytes, releasing many antibody copies to neutralize or destroy their
target antigen.
2. What is a way that Adaptive Immunity can
recruit innate immunity?
The innate immune response to microbes stimulates adaptive immune
responses and influences the nature of the adaptive responses. Conversely,
adaptive immune
