Physiology 1 Flashcards
what is tonicity?
the effect a solution has on cell volume
osmolality is the same as osmolarity T or F
T, only difference is the units used
what is osmolarity?
concentration of osmotically active particles present in a solution
what are the units for osmolarity?
mosmol/l (milliosmoles per l)
what 2 factors need to be known in order to calculate osmolarity?
molar conc of solution
number of osmotically active particles present
less water outside of the cell compared to inside indicates a ___ ___
hypertonic solution
if the osmolarity inside and outside of tehe cell is the same the solution is said to be ___
isotonic
what percentage of a female’s body weight is made up of water?
50%
what percentage of a male’s body weight is made up of water?
60%
around 2/3 of all water of the body is found in __
cells (ie intracellular fluid)
what makes up most of the extracellular fluid?
interstitial fluid
how is plasma measured?
labelled albumin
TBW (total body water) = ___ + ___
ECF + ICF
name the equation required to work out the volume of a compartment
dose/sample concentration
why do we get water from metabolism?
many by-products/final products of metabolic processes are water
biggest loss of water from the body?
urine
how much urine is lost on average per day?
1500ml
why can urine production never be turned off?
some products can only be excreted as a solution
there are more sodium and chloride cells ___ the cell compared to ___
outside
inside
what structure separates plasma from the interstitial fluid?
capillary wall
negatively charged proteins are more prevalent in the ECF T or F?
F, mainly in ICF
the osmotic concentration of the ICF is?
300mosmol/l
the osmotic concentrations of the ECF is?
300mosmol/l
movement of water between the ICF and ECF in response to an osmotic gradient is known as?
fluid shift
what would happen to the ICF volume if the ECF osmotic conc decreases?
ICF increases
what effect would decreased ECF volume have on plasma volume?
would decrease it
when would electrolyte balance occur?
when rates of gain = rates of loss
total electrolyte concentrations have no effect on osmolarity T or F
F, can directly affect water balance
“water will follow salt whenever possible” T or F
T
main salts of the ECF?
Na
Cl
how does salt get into the body?
fluids and food
