Body Fluid Compartments Flashcards Preview

Human Epithelial Biology > Body Fluid Compartments > Flashcards

Flashcards in Body Fluid Compartments Deck (42)
1

What are the units of osmolarity?

osmol/l

2

What is required to calculate osmolarity?

2 factors i.e. 150mM NaCl and 100mM MgCl2

3

What is tonicity?

the effect on cell volume
isotonic - normal
hypotonic - too much water
hypertonic - too little water

4

What does hypertonicity cause?

cell shrinkage

5

What does hypotonicity cause?

cell lysis from swelling

6

What are the units of osmolality?

osmol/kg

7

What is different between osmolarity and tonicity?

tonicity takes into consideration the ability of a solute to cross the cell membrane

8

What is the Total Body Water percentage of a male and female?

male 60% of body weight
female 50% of body weight

9

What does total body water exist as?

2 major compartments of ICF and ECF

10

What is the concentration of water in ICF and ECF?

ICF 67% TBW
ECF 33% of TBW

11

What is included in EC fluid?

plasma
interstitial fluid
lymph - negligible
transcellular fluid - negligible

12

How might you trace TBW?

3H2O

13

How might you trace ECF?

Inulin

14

How might you trace plasma?

labelled albumin

15

What is TBW equivalent to?

ECF+ICF

16

How do you measure the volume of distribution?

take the tracer and equilibrate it with water
take a small sample and measure the concentration
c=m/v
work out volume of distribution

17

What is the equation for calculating the volume of distribution?

V (L)=Dose/Sample concentration

18

What is insensible loss of water?

loss through skin and lungs

19

What is sensible loss of water?

faeces
urine
sweat

20

What is the general input and output of water/day?

2500ml

21

What may increase water loss through sweat?

hot weather and exercise

22

What may increase water loss through the lungs?

exercise

23

What decreases the water loss from urine?

hot weather and exercise

24

What is the general ICF and ECF concentrations of Na?

ICF - 10
ECF -140

25

What is the general ICF and ECF concentrations of K?

ICF - 140
ECF - 4.5

26

What is the general ICF and ECF concentrations of Cl?

ICF - 7
ECF - 115

27

What is the general ICF and ECF concentrations of HCO3?

ICF -10
ECF -28

28

What is particularly potent in the plasma?

Na, Cl, HCO3, protein anions

29

What is particularly potent in the interstitial fluid?

Na, HCO3, Cl

30

What is particularly potent in the IC fluid?

K, PO4, Mg, protein anions, small Na

31

What is the difference in osmotic concentration of ECF and ICF?

none - they are identical

32

Why is there no difference in ICF and ECF?

because any change in solute concentration leads to immediate change in water distribution

33

What is fluid shift?

the movement of water between the ICF and ECF in response to an osmotic gradient

34

What are some challenges to fluid homeostasis?

gain or loss of water
gain or loss of NaCl
gain or loss of isotonic fluid

35

What happens when NaCl is gained in the ECF?

ECF increases water volume
ICF decreases water volume

36

What happens when NaCl is lost in the ECF?

ECF loses water volume
ICF gains water volume

37

what does a gain or loss of isotonic fluid cause?

change in ECF volume but not fluid osmolarity

38

What alters the composition and volume of the ECF?

kidney

39

What is regulation of ECF vital for?

regulation of blood pressure

40

What is electrolyte balance important for?

can directly affect water balance
the concentrations of electrolytes can affect cell function

41

What is particularly important about Na and K?

they are major contributors to the osmotic concentrations of ECF and ICF
they directly affect the functioning of all cells

42

What can result from increasing plasma K?

muscle weakness - paralysis
cardiac irregularities - cardiac arrest