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Flashcards in 8. Fluid compartments Deck (24):
1

Total body water ( TBW ) - proportion

60% of body mass

2

Non water mass ( NWM) - proportion

40% body mass

3

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

4

Total body water ( TBW) is divided to ... ( and proprotions)

1. extracellular fluid ( ECF) --> 1/3
2. intracellular fluid ( ICF) --> 2/3

5

extracellular fluid (ECF) in a body mass 70 kg

1/3 of 60% body mass --> 20 % of body mass--> 14 kg ---> 14L

6

intracellular fluid ( iCF) in body mass 70 kg

2/3 of 60% body mass --> 40 % of body mass --> 28kg --> 28L

7

extracellular fluid ( ECF) vs intracellular fluid ( ICF) according to proportion in body mass

extracellular fluid ( ECF) --> 20%
intracellular fluid (ICF) --> 40%

8

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

9

RBC volume

2.8L ( PART OF intracellular fluid)

10

blood constist of ( and volumes )

RBCs (2.8L ) and plasma (3.5L) -->6.2L

11

Normal HCT ( calculation and alternative calculation)

RBC volume / blood volume = 2.8 / 6.2 = 45%
alternatively --> HCT (%) = 3X(Hb) in g/dL

12

Plasma volume can be measured by

radiolabelling albumin or Evans blue ( it binds albumin )

13

Extracellular volume can be measured by

inulin or manitol, sulfate

14

osmolarity is the

measure of solute concentration, defined as the number of osmoles ( Osm ) of solute per litre (L) of solution

15

osmolarity - normal range

285-295 mOsm/ kg H2O

16

Nonwater mass accounts for ____% of total body weight, or ____ kg in a person weighing 70 kg.

40%; 28 kg

17

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

18

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

19

• 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)

20

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?

285–295 mOsm/kg

21

• Of the extracellular fluid, what percentage is interstitial fluid, and what percentage is plasma?

75; 25%

22

• 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

23

• What is the volume of water contained within RBCs in the intracellular fluid of a 70-kg man?

2.8 L

24

• What is the total blood volume of an average 70-kg man? Of this volume, what percentage is hematocrit (HCT)? How is HCT calculated?

6 L; 45%; HCT (%) ∼ 3 × [Hb] in grams per deciliter

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