Body Fluid Compartments Flashcards Preview

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Flashcards in Body Fluid Compartments Deck (45)
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1

When you have water deprivation what happens?

increase plasma osmolarity-> stimulates osmoreceptors in anterior hypothalamus-> increase secretion of ADH from posterior pituitary-> increases water permeability of late distal tubule and collecting duct-> increases water reabsorption-> increase urine osmolarity and decreases urine volume-> decreases plasma osmolarity toward normal

2

What happens when you have water intake?

Decrease plasma osmolarity-> decrease ADH-> decrease water reabsorption-> decrease urine osmolarity and increases urine volume-> increases plasma osmolarity towards normal

3

How do you measure fluid compartments?

quantity of tracer/ concentration of tracer

4

What is the typical percent of water out of total body weight? What can decrease this number?

~60%
being really fat

5

What is the eqn for intracellular fluid volume?

Total body water-EFV

6

What is the eqn for blood volume?

plasma volume/ (1-hct)

7

What is the eqn for interstitial fluid volume?

EFV-PV

8

What do you use to find Plasma volume?

Albumin levels

9

What percent of water is inside cells?
Outside cells?
Total water in your body?

40%
20%
60% of your body weight is water

10

Na is essentially a (blank) ion

extracellular

11

K is essentially a (blank) ion

intracellular

12

The intracellular compartment behaves as a perfect (blank)

osmometer (measures oncotic pressure)

13

typically the ICF and ECF have the same what?

osmolality of 300 mOsm/L H20

14

What happens when you have overhydration?

Increase ECF volume

15

What happens when you have isotonic overhydration (careless admin. of saline)?

expand ECF volume

16

What happens when you have hypertonic overhydration?

expansion of ECF with hypertonic solution, water shifts from ICF into ECF. Increase in ECF, decrease in ICF, increased osmolality in both ECF & ICF.
i. Drinking sea water

17

What happens when you have hypotonic overhydration?

increase in volume of both ECF and ICF compartments and thus a decrease in osmolality in both compartments.
i. Compulsive water drinking

18

What happens when you have dehydration?

decrease in ECF volume

19

What happens when you have isotonic dehydration?

reduction in ECF volume i. -Hemorrhage

20

What happens when you have hypotonic dehydration?

water moves into ICF increasing ICF fluid, decreasing ECF and decreasing osmolality of both.
i. Adrenal cortical insufficiency (Addison's disease)
1) Not enough aldosterone- lose salt

21

What happens when you have hypertonic dehydration?

loss in water from ECF, so water moves from ICF into ECF, decreasing volume in both compartments, osmolality increase in both compartments because of loss in water.
i. Lost In desert without access to water
1) Loss of water through sweat (no salt loss)
ii. Diabetes insepidus (lack ADH)

22

Departure from normal (Blank) suggests there are disturbances in fluid balance. But this CAN remain normal with (blank) (overadmin of IV or hemmorage). It can also decrease with (blank) like water intoxication or addisons disease.

extracellular Na
volume disturbances
dehydration or overhydration

23

Extracellular Na can increase with (blank) or (blank).
How do you distinguish between these cases of hypernatremia?

overhydration or dehydration
Via plasma proteins!

24

If you have hypernatremia due to overhydration what will happen to your plasma protein levels?

Decrease (think salt water)

25

If you have hypernatremia due to dehydration what will happen to your plasma protein levels?

Increase (think lost in desert)

26

If a healthy individual loses 2 liters of sweat and simultaneously drinks 2 liters of pure water what will occur?

You will have a net loss of salt which will decrease plasma osmolarity, decrease intracellular osmolarity, decrease extracellular volume, increase intracellular volume and decrease total solute content in the body
(SAME AS ADDISONS disease!)

27

Urine flow and sweat have what kind of relationship?

inversely proportional

28

Water (blank) is essential

homeostasis

29

What is the rate of loss of water in the GI tract?

8200 ml/day

30

Regulation of plasma osmolality is done via what??

ADH and thirst