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
... [Show More] 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?
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.
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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
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
Describe the laboratory findings associated with metabolic acidosis, metabolic
alkalosis, respiratory acidosis and respiratory alkalosis. (ie relative pH and CO2
levels).
Respiratory Acidosis:
Ph <7.35, CO2 >45, HCO3 >26
Respiratory Alkalosis:
Ph >7.35, CO2 <35, HCO3 <22 [Show Less]