electrolytes

Question 1

What lab value is different between the plasma and ISF?

Answer 1

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

Question 2

Why are the plasma and ISF labs equal?

Answer 2

capillary membrane in porous/permeable allowing electrolytes to shift equally between them

except proteins or in the brain capillaries

Question 3

Sodium

Answer 3

predominant (+) cation ECF
ex) cut lip is salty

plasma: 140 mEq/L
osmolarity= Na x2

ICF: 14 (1/10th of the ECF)

Question 4

Potassium

Answer 4

Predominant ICF

plasma: 4 mEq/L
ICF: 120 (30X HIGHER)

• cardiac electrical activity
• if K leaves a cell (necrosos/sepsis) very bad

Question 5

Calcium

Answer 5

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

Question 6

Magnesium

Answer 6

Mg++

important co-factor for intracellular chemical rxns… WHY its mainly ICF electrolyte

can be used to settle the heart

Question 7

Chloride

Answer 7

Cl-
primary anion in ECF, follows sodium

Question 8

Bicarb

Answer 8

HCO3-

secondary anion in ECF

managed by the kidney: buffer for pH

primary ECF buffer

Question 9

Phosphate

Answer 9

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

Question 10

Amino Acids

Answer 10

higher in ICF because:

• make up proteins inside the cell
• protein breakdown in the cell that we need to replace

Question 11

Creatinine

Answer 11

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

Question 12

Lactate

Answer 12

by product of metabolism
- metabolism happens in our cells…. so higher in ICF

Question 13

ATP

Answer 13

“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

Question 14

Glucose

Answer 14

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

Question 15

Protein

Answer 15

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

Question 16

Urea

Answer 16

by product of metabolism… even in all compartments

used by kidney for water management

Question 17

Total mOsm/L

Answer 17

“predicted” 300 mOsm/L

how many dissolved compounds in a fluid sample

Question 18

Corrected Osmolar Activity

Answer 18

280-283 mOsm/L

“biologic”

lower than total osmo because not all ions are freely dissociated from one another

Question 19

Total Osmotic Pressure at 37 degrees

Answer 19

> 5,000 mmHg

from all the things dissolved in our body fluid

total fluid/hydrolic pressure generated via osmosis

corrected x19.3 mmHg/mOsm

Question 20

Why are osmo levels consistent between the ECF and ICF?

Answer 20

water movement isn’t inhibited between the dividers of these compartments

equal pressures= no damage

ex: CNS in a closed compartment

Question 21

what’s the major plasma protein

Answer 21

albumin

Question 22

Osmolality

Answer 22

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

Question 23

Osmolarity

Answer 23

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

Question 24

19.3?

Answer 24

19.3 mmHg per osmo

each osmo of stuff dissolved int 1kg of water can exert 19.3 mmHg of pressure