body fluid compartments Flashcards
what is osmosis
diffusion of water form high to low solutes
what is osmolarity
[C} of all particle mosm/L
what is normal body osmolatiry
295 mosm/L
what are 2 types of pressure that can move fluids
- hydrostatic - push
2. osmosis - pulls (sucking)
what is total body water in men and women
men - 60%
women - 50%
how much water in most tissue
75-80%
where is total body water
ECF - 1/3
ICF - 2/3
where is most ECF water
interstitial 3/4 (25% total)
plasma 1/4 (8% total)
what is composition of plasma
93% water, 7% solids
what is sequestered water
unavailable water in the bone and CT - not counted for calclulations
what factors affect water
age - less with age
women - less water
fat - less with fat
what is average blood volume
70cc/kg – 5L in normal male - 3L plasma
what is border between ICF and other
cell membrane
what is border between plasma and ISF
cap walls
how does water get into cells
through aquaporin channels
what happens when add salt to body
water exits cells
what is tonicity
[C] off effective osmoles (usually Na)
what is hypertonic
more solute than normal
what are main ECF and ICF cations
ECF - Na
ICF - K
what maintains differences between Na and K
ATP ase - NA out and K in
what is normal ECF [Na}
140
what percentage of osmolarity is Na
95%
what is size of ICF and ECF compartments dep on?
water - follows the solutes, but solutes don’t pass easily
what is osmolarity forumula
particles/vol
