-
How much of your body is made of water
60%
-
Extracellular fluid (ECF) includes what compartments
- Interstitial Fluid (IF)
- Plasma Volume
- Transcellular fluid
-
In what ways can you estimate body fluid volumes
- By using a percent of the total body mass.
- By using a percent of total body water.
- By using a percent of extracellular fluid
-
What are the percentages of each compartment in respect to our total body weight
- Plasma Volume (PV) 20% of ECF
- Interstitial Fluid (IF) 75% of ECF
- Transcellular Fluid 5% of ECF
- Intracellular Fluid (ICF)60% of TBW
-
What percent of the body is made of the Extracellular fluid
40% (60%) Intracellular
-
Indicator Dilution Method is performed how
- Determination of compartmental volume
- 1.Place indicator A in the compartment B.
- 2.Allow it to disperse evenly though out the compartment’s fluid
- 3.Analyze the extent to which the substance is diluted
-
Indicator Dilution Method equation
Vol (B) = (Vol (A) x Conc (A))/ Conc (B)
-
Indicators for Plasma Volume (PV)
125I-albumin, Evans blue dye
-
Indicators for Extracellular Fluid (ECF)
inulin, mannitol
-
Indicators for Total Body Water (TBW)
3H2O, antipyrine
-
A 70 kg, 28 yr female presented after fainting while getting ready for work. 10 mL of an isotonic saline solution with the addition of 45 mg/mL of inulin was administered to her (‘Elizabeth’) through an arm vein. After a 4 hour equilibration period, a blood sample is withdrawn and the plasma is separated and analyzed for inulin content. A concentration of 0.05 mg/ml of inulin was found. What is the ECFV level of the patient?
(10mlx45mg/ml)/(.05mg/ml)=9000ml(9L)
-
Osmolarity
is the measure of solute concentration, defined as the number of osmoles (Osm) of solute per liter (L) of solution (osmol/L or Osm/L).
-
Osmolality
Osmoles per kilogram of water (Osm/Kg)
-
The osmotic pressure of a solution is
The pressure necessary to stop the net movement of water across a selectively permeable membrane.
-
Van’t Hoff equation tells you
- The more permeable the membrane is for a solute (lower f), the lower the osmotic pressure.
- The less permeable the membrane is for a solute (higher f), the higher the osmotic pressure.
-
An impermeable substance such as albumin exerts its own osmotic effect known as
- Colloid osmotic pressure or plasma oncotic pressure. (GIBBS-DONNAN EFFECT) It is used in the kidneys to keep a healthy pressure in the capillaries
Protein repels permeable anions such as Cl-
-
Which has a lower chloride concentration the plasma or Interstitial fluid, why?
The plasma, calloid osmotic pressure it repels Cl-
-
Tonicity
Tonicity is a measure of the osmotic pressure of two solutions separated by a semipermeable membrane (So the cell must expand or shrink)
-
Osmotic vs. Tonic
Solution of molecules freely permeable to the plasma membrane (Osmotic) as aposed to those that aren't permeable (Tonic)
-
‘Elizabeth’, the same patient as previously analyzed, was also administered 30 mL of tritiated water (3H2O) as an isotonic saline solution (300 mOsm/L) into an arm vein. Similarly, after a 2 hr equilibration period, a blood sample is withdrawn and the plasma is separated and analyzed for 3H2O. A concentration of 0.2432 mOsm/L 3H2O was found. Based on this information, and that found previously, what is the ICFV of the patient?
- (.03Lx300mosm/L)/.2432mosm/L=
- 37-9=28
-
Men have a Total Body water (TBW) average of
60% of their weight is from water
-
Women have a Total Body water (TBW) average of
50% of their body weight is water
|
|
