electrolytes Flashcards
What lab value is different between the plasma and ISF?
protein
PLASMA: 1.2 (5X HIGHER)
- if we loose albumin it will be hard to keep blood in the right place of the body
- liver makes plasma proteins and places them in CV system
INTERSTIAL: 0.2
-lots of water, not a lot of protein
Why are the plasma and ISF labs equal?
capillary membrane in porous/permeable allowing electrolytes to shift equally between them
except proteins or in the brain capillaries
Sodium
predominant (+) cation ECF
ex) cut lip is salty
plasma: 140 mEq/L
osmolarity= Na x2
ICF: 14 (1/10th of the ECF)
Potassium
Predominant ICF
plasma: 4 mEq/L
ICF: 120 (30X HIGHER)
- cardiac electrical activity
- if K leaves a cell (necrosos/sepsis) very bad
Calcium
Ca++
hardly no calcium inside a cell
1:10,000
used as a signal to turn on/off cells by pumping through cell wall
- resting cell (low calcium)
- neurotransmitter hits cell (high calcium)
- important for neuro and muscle
Magnesium
Mg++
important co-factor for intracellular chemical rxns… WHY its mainly ICF electrolyte
can be used to settle the heart
Chloride
Cl-
primary anion in ECF, follows sodium
Bicarb
HCO3-
secondary anion in ECF
managed by the kidney: buffer for pH
primary ECF buffer
Phosphate
HPO4
H2PO4-
-ICF buffer
- when added/removed from a target turns a switch on/off (vice/versa) PHOSPHORYLATION/ dephosphorylation
- energy storage for ATP (primary energy currency in the cell)
- add phosphate to adenosine=requiring energy
*remove phosphate from adenosine= energy released
Amino Acids
higher in ICF because:
- make up proteins inside the cell
- protein breakdown in the cell that we need to replace
Creatinine
high energy storage compound that can be used before ATP
- higher in ICF
skeletal muscle cells have creatinine compound that can be phosphorylated by adding a phosphorus (phosphocreatinine)
- high exertion causes a phosphorus to be pulled off
short term energy reserve, depleted quickly
Lactate
by product of metabolism
- metabolism happens in our cells…. so higher in ICF
ATP
“adenosine triphosphate”
- used inside cells (ICF)
- BUT adenosine can leak outside of cells if you pull 3 phosphates off adenosine… increasing blood flow to high metabolically active tissues (vasodilation)
ex) ADP: adenosine diphosphate
ex) AMP: adenosine monophosphate
Glucose
blood work numbers (mg/dL)
-most cells don’t produce glucose (they use it)
- comes form outside of cells
- higher in the ECF
- charged/polar
Protein
PLASMA: 5x higher than the INTERSTITIAL… b/c liver makes plasma proteins and puts them in the CV system
*highest in the ICF because made inside the cell, function, stored
Urea
by product of metabolism… even in all compartments
used by kidney for water management
Total mOsm/L
“predicted” 300 mOsm/L
how many dissolved compounds in a fluid sample
Corrected Osmolar Activity
280-283 mOsm/L
“biologic”
lower than total osmo because not all ions are freely dissociated from one another
Total Osmotic Pressure at 37 degrees
> 5,000 mmHg
from all the things dissolved in our body fluid
total fluid/hydrolic pressure generated via osmosis
corrected x19.3 mmHg/mOsm
Why are osmo levels consistent between the ECF and ICF?
water movement isn’t inhibited between the dividers of these compartments
equal pressures= no damage
ex: CNS in a closed compartment
what’s the major plasma protein
albumin
Osmolality
how much quantity we have dissolved in 1 kg of water
-how to calculate osmotic pressure
- more accurate but impractical
quantity (mOsm or mEq) DIVIDED by
1 Kg or 1 L H2O
Osmolarity
quantity of things dissolved in 1 L or solution
- the term we use in class
- less water content compared to osmolarity b/c it contains solids dissolved in it which displaces the water that would have normally been there
quantity (mOsm or mEq)
DIVIDED by
1 L solution
1% difference from osmolality
19.3?
19.3 mmHg per osmo
each osmo of stuff dissolved int 1kg of water can exert 19.3 mmHg of pressure
