Body Fluid Compartments Flashcards
What are the units of osmolarity?
osmol/l
What is required to calculate osmolarity?
2 factors i.e. 150mM NaCl and 100mM MgCl2
What is tonicity?
the effect on cell volume
isotonic - normal
hypotonic - too much water
hypertonic - too little water
What does hypertonicity cause?
cell shrinkage
What does hypotonicity cause?
cell lysis from swelling
What are the units of osmolality?
osmol/kg
What is different between osmolarity and tonicity?
tonicity takes into consideration the ability of a solute to cross the cell membrane
What is the Total Body Water percentage of a male and female?
male 60% of body weight
female 50% of body weight
What does total body water exist as?
2 major compartments of ICF and ECF
What is the concentration of water in ICF and ECF?
ICF 67% TBW
ECF 33% of TBW
What is included in EC fluid?
plasma
interstitial fluid
lymph - negligible
transcellular fluid - negligible
How might you trace TBW?
3H2O
How might you trace ECF?
Inulin
How might you trace plasma?
labelled albumin
What is TBW equivalent to?
ECF+ICF
How do you measure the volume of distribution?
take the tracer and equilibrate it with water
take a small sample and measure the concentration
c=m/v
work out volume of distribution