Module 4: Electrolytes Flashcards
What mechanisms balance water and electrolytes?
Thirst - (Osmoreceptors in the hypothalamus)
Antidiuretic hormone (ADH) - (Reabsorption of water from the kidney tubules)
Aldosterone - (Reabsorption of sodium and water)
Atrial natriuretic peptide (ANP) and T-type natriuretic peptide -
(Synthesized by myocardial cells
Regulation of fluid, sodium, and potassium levels)
Fluid circulates the body via
Filtration and osmosis (depending on membrane permeability)
Water moves through compartments via
- Hydrostatic pressure
- Osmotic pressure
Edema is excessive amount of fluid in the
Interstitial compartment
What are the three spaces of the body?
Intracellular – within the cell
Intravascular - Within the blood vessel
Interstitial – everything in between, what tissue cells are bathed in
Hydrostatic pressure may be viewed as the ________ force
“Push”
Osmotic pressure may be viewed as the ________ force
“Pull”
What are 4 causes of edema?
- Increased capillary hydrostatic pressure
- Loss of plasma proteins
- Obstruction of lymphatic circulation
- Increased capillary permeability
Increased capillary hydrostatic pressure is caused by?
And forces increased fluid out of capillaries into _____
Is the cause of _____
Higher blood pressure or increased blood volume
- tissue
- Cause of pulmonary edema
Loss of plasma proteins, because of Adema, results in decreased___________
Plasma osmotic pressure
Obstruction of lymphatic circulation causes ____________ and excessive fluid and proteins are not returned to __________
Localized edema
General circulation
What increases capillary permeability?
Histamines and other chemical mediators
What are the effects of edema? (8)
Swelling-local area, Heading Adema, increase in body weight, functional impairment, pain, impaired arterial circulation, dental complications, edema in skin (susceptible to tissue breakdown from pressure)
What is hyponatremia?
Refers to a serum sodium concentration below 3.8 to 5 mmol/L
What is hypernatremia?
Excessive sodium level in the blood and extracellular fluids
Cause is imbalance in sodium and water
Excess potassium ions in interstitial fluid may lead to
Hyperkalemia
What are some affects of hyperkalemia?
Cardiac dysrhythmias, muscle weakness is common, fatigue, nausea, paresthesias (abnormal sensation, typically “pins and needles” caused chiefly by pressure on or damage to peripheral nerves)
What are the four major factors affecting the sodium balance of the body?
- aldosterone
- natriuretic hormone
- antidiuretic hormone
- The amount of free water in the body
What system is most seriously affected by potassium imbalance?
The cardiovascular system – specifically the heart
Potassium imbalances (both high and low levels) interfere with
Both conduction through the heart and the contraction of the heart muscle - This leads to arrhythmias and can possibly lead to cardiac arrest and death
How does the body compensate for acidosis?
- deep rapid breathing (increases the amount of carbon dioxide exhaled)
- Kidneys try to compensate by excreting more acid in the urine
Compensation mechanisms for pH imbalance occurs to balance the relative proportion of
Hydrogen ions and bicarbonate ions in circulation
Acidosis means
- Excess hydrogen ions
- Decrease in serum pH
Alkalosis is
- Deficit of hydrogen ions
- Increase in serum pH
What is oncotic Pressure?
Pressure exerted by proteins in plasma
What are 4 causes of edema?
- Increased capillary Hydrostatic pressure
- Loss of plasma proteins (particularly albumin)
- Obstruction of lymphatic circulation
- Increased capillary permeability
