Body fluid content Flashcards
Transcellular compartments
3rd spaces
included in the ECF
small amts of water in epi secretions, synovial, CSF etc
if there is overflow of ICF during diseases=”3rd spacing” i.e. fluid enters these extra compartments
ECV
the amount of blood in the arterial circulation
**independent of other parameters (ECFV, plasma volume, CO etc)
Volume of distribution
apparent volume of body fluid in which the total dose of the drug is distributed at the same concentration as in the plasma
> any drug goes thru ECF first
Vd<3
plasma only
Vd=14
drug in plasma and ECF
Vd=40-45
drug occupies TBW
Vd>45
drug widely distributes and enters 3rd compartments and body tissues
Donnan effect
higher plasma Na and K compared to interstitial fluid due to the presence of protein albumin
Tissue damage after hypoxia
hypoxia—>no Na-K pump—>inc ICF Na—>H2O rushes in and cell swells and dies
crystalloid fluids
contain varying concentrations of electrolytes and can stay in ECF or be widely distributed depending on content (e.g. normal saline, lactated Ringer’s)
Colloid fluid
if problems are just in vasculature, want to pull fluid out of IC spaces
contain large proteins that stay w/in the vascular space (pull fluid from spaces from ISF into the vasculature ECF
(e.g. dextran, albumin)
isosmotic
same Osm of ECF, does not change plasma Osm, just increases volume
hyperosmotic
have Osm greater than ECF
when added, Osm increases and causes water to move from teh cells to the ECF compartment with resulting increase in ECF volume and dec ICF volume
hyposmotic
have lower Osm, more water
when added, decreases Osm, fluid moves into the cells, ECF and ICF volume increase
tonicity
water movement due to osmotic eq with water movement across membrane
