Flashcards in 8. Fluid compartments Deck (24):
Total body water ( TBW ) - proportion
60% of body mass
Non water mass ( NWM) - proportion
40% body mass
total body water mass and non water mass if Body mass is 70 Kg
-total body water --> 60 % of body mass= 42 kg = 42 L
-non water mass--> 40% of body mass = 28kg
Total body water ( TBW) is divided to ... ( and proprotions)
1. extracellular fluid ( ECF) --> 1/3
2. intracellular fluid ( ICF) --> 2/3
extracellular fluid (ECF) in a body mass 70 kg
1/3 of 60% body mass --> 20 % of body mass--> 14 kg ---> 14L
intracellular fluid ( iCF) in body mass 70 kg
2/3 of 60% body mass --> 40 % of body mass --> 28kg --> 28L
extracellular fluid ( ECF) vs intracellular fluid ( ICF) according to proportion in body mass
extracellular fluid ( ECF) --> 20%
intracellular fluid (ICF) --> 40%
extracellular fluid ( ECF) is divided to ( proportions and L in body mass 70 kg)
1. interstitial fluid --> 75% ECF -->10.5 L
2. plasma --> 25% ECF --> 3.5 kg ---> 3.5 L
2.8L ( PART OF intracellular fluid)
blood constist of ( and volumes )
RBCs (2.8L ) and plasma (3.5L) -->6.2L
Normal HCT ( calculation and alternative calculation)
RBC volume / blood volume = 2.8 / 6.2 = 45%
alternatively --> HCT (%) = 3X(Hb) in g/dL
Plasma volume can be measured by
radiolabelling albumin or Evans blue ( it binds albumin )
Extracellular volume can be measured by
inulin or manitol, sulfate
osmolarity is the
measure of solute concentration, defined as the number of osmoles ( Osm ) of solute per litre (L) of solution
osmolarity - normal range
285-295 mOsm/ kg H2O
Nonwater mass accounts for ____% of total body weight, or ____ kg in a person weighing 70 kg.
40%; 28 kg
What fraction of total body water is extracellular vs. intracellular? What fraction of extracellular fluid is plasma vs. interstitial?
Total body water = one third extracellular, two thirds intracellular; of extracellular fluid = one fourth plasma, three fourths interstitial
In an experiment, radiolabeled albumin and, later, radiolabeled inulin are infused into a patient. What two variables are being measured?
Radiolabeled albumin may be used to measure plasma volume, and inulin may be used to measure extracellular volume
• What is the 60-40-20 rule of (percentage of body weight) for the average person?
60% of total body weight is total body water, 40% is intracellular fluid (ICF), and 20% is extracellular fluid (ECF)
A healthy patient's plasma osmolarity is measured during a routine visit. It is found to be normal. What value do you expect to see?
• Of the extracellular fluid, what percentage is interstitial fluid, and what percentage is plasma?
• Of the extracellular fluid in a 70-kg man, what volume and mass is the interstitial fluid, and what volume and mass is the plasma?
10.5 L and 10.5 kg; 3.5 L and 3.5 kg
• What is the volume of water contained within RBCs in the intracellular fluid of a 70-kg man?