Fluids and Electrolytes Flashcards
what are the three fluid compartments
intracellular, interstitial, intravascular
what is a hypotonic solution
lower solute concentration than another solution
where does the fluid shift with a hypotonic solution
fluid shifts from ECF to ICF
what is a hypertonic solution
higher concentration than another solution
where does the fluid shift with a hypertonic solution
fluid shifts from ICF to ECF
4 ways cell maintain homeostasis
diffusion, osmosis, filtration, active transport
how does diffusion work
SOLUTES move from higher concentration to lower concentration
how does osmosis work
passive movement of a SOLVENT(FLUID) from an area of lower concentration to one of a higher concentration
how does capillary filtration occur
blood pushes against capillaries into interstitial fluid by hydrostatic pressure; fluids and solutes forced through capillary wall
how does reabsorption work
prevents to much fluid from leaving capillaries regardless of hydrostatic pressure
what role does albumin play with reabsorption
albumin stays in capillaries and as albumin increases with fluid shift, fluid will move back into capillaries by osmosis
what is the normal plasma colloid osmotic pressure
25 mmhg
if hydrostatic pressure is greater than plasma colloid osmotic pressure what happens
water and solute leave capillaries and enter interstitial fluid
normally capillary BP is ______ than plasma colloid pressure in arteriole
greater
normally capillary BP is ____ than venoule
less
how does active transport work
solutes move from lower concentration to higher concentration
what does active transport require
energy and the sodium potassium pump
what 3 things maintain fluid balance
kidneys, hormones, thirst
how do the kidneys maintain fluid balance
nephrons filters blood and forms urine and changes based on fluid balance/needs
what is stored and released in the posterior pituitary gland
ADH (vasopressin)
how does ADH work
its a water retainer
when is ADH released
with increased serum osmolality and decreased blood volume
how does the renin-angiotensin aldosterone system work
juxtaglomerular cells release renin - renin releases angiotensin II, angiotensin causes peripheral vasoconstriction and stimulates production of aldosterone - raising blood pressure, and NA/H2O are retained
how does active transport work
solutes move from an area of lower concentration to an area of higher concentration - requires energy
what does aldosterone regulate
reabsorption of sodium and water
what triggers active transport
when blood volume drops, aldosterone signals active transport of sodium to increase BP
what counteracts the effects of the renin-angiotensin-aldosterone system
atrial natriuertic peptide
what does ANP do
reduces BP and intravascular blood volume, increases urine excretion of na/h2o, and causes vasodilation
when is ANP released
when na/h2o are increased
what are the major electrolytes of the ecf
sodium and chloride
what does sodium concentration effect
serum osmolality and ECF fluid volume
what does chloride help maintain
osmotic pressure (h2o pulling pressure)
what other electrolytes are found in ECF
calcium/bicarb
what are the most abundant electrolytes in ICF
potassium, phosphorus, and magnesium
what is potassium responsible for
intracellular osmolality control
what does magnesium aid in
protein synthesis and sodium/potassium ion transport
what can a diuretic cause a loss of
electrolyte loss
what can an IV fluid cause a gain of
electrolyte gain
what is key in assessing a patients fluid status
BP measurement
what does dehydration cause
a loss of body fluids that causes blood solute concentration to increase (increase osmolality) and serum sodium levels to rise
what shifts out of cells during dehydration
water shifts out of cells into more concentrated blood
how do the kidneys help with dehydration
retain water that usually helps restore body fluid volume
what signs can you see for dehydration
decreased BP/urine output and increased HR
treatment for dehydration includes
avoiding hypertonic solution, can give hypotonic, NS, or dextrose in water
what can happen if u give hypotonic solution to rapidly for dehydration
cerebral edema so must be given over 48 hours
what is lost in hypovolemia and where
isotonic fluid loss (loss of fluids and solutes) from ECF
what is a third space fluid shift
when fluid moves out of intravascular space but not into intracellular space
when can third spacing occur
when there is an increased permeability of capillary membrane or decreased plasma colloid osmotic pressure
what is seen with hypervolemia
excess of isotonic fluid in ECF
where can the increase be seen
interstitial or intravascular compartments
what makes up the ECF
interstitial (fluid surrounding cells) and intravascular compartments (plasma/liquid portion of blood)
how can body compensate and restore fluid balance in hypervolemic state
fine tuning circulating levels of ADH, aldosterone, and ANP
how does water intoxication occur
when excess fluid moves from ECF to ICF
how does water intoxication occur
excessive low sodium fluid in ECF is hypotonic to cells and the cells are hypertonic to the fluid; bc of imbalance fluid shifts by osmosis into cells causing them to swell
what does SIADH stand for
syndrome of inappropriate antidiuretic hormone
what does SIADH do
ADH secretion can cause h2o intoxication by causing the body to hold onto electrolyte free h2o despite low plasma osmolality and high fluid volume
what are the anions
bicarbonate, chloride, phsophorus
what are the cations
calcium, magnesium, potassium, sodium
what are the extracellular electrolytes
sodium, chloride, calcium, bicarbonate
what are the intracellular electrolytes
potassium, phosphate, magnesium
