WGU
pathophysio
logy D236-
ExamQuesti
ons and
Answers
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
,WGU
pathophysio
logy D236-
ExamQuesti
ons and
Answers
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.
,WGU
pathophysio
logy D236-
ExamQuesti
ons and
Answers
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.
, WGU
pathophysio
logy D236-
ExamQuesti
ons and
Answers
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
pathophysio
logy D236-
ExamQuesti
ons and
Answers
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
,WGU
pathophysio
logy D236-
ExamQuesti
ons and
Answers
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.
,WGU
pathophysio
logy D236-
ExamQuesti
ons and
Answers
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.
, WGU
pathophysio
logy D236-
ExamQuesti
ons and
Answers
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
