L3 Body Fluids

Question 1

Distribution of Body Water

Total body water (TBW)

Answer 1

TBW = ICF + ISF + plasma
60-40-20 rule (% distribution)

TBW=60% body weight
ICF=40% body weight
ECF=20% body weight

Question 2

How does water content correlate to body fat stores?

Answer 2

Inversely

Question 3

Total body water =

Answer 3

0.7LBM + 0.1AT

Lean body mass (kg)
Adipose tissue (kg)

Question 4

If you don’t know LBM..

Answer 4

TBW= 0.6(weight kg)

Question 5

At equilibrium all body water compartments have

Answer 5

The same osmolarity

It’s estimated from plasma osmolarity

Question 6

Estimating plasma osmolarity equation

Answer 6

Osmolarity =
(2Na+)+ (glucose/18) + (BUN/2.8)

BUN= blood urea nitrogen

Question 7

Capillary endothelium and most cell membranes are

Answer 7

Permeable to water

Question 8

Plasma, interstitial fluid, and ICF have

Answer 8

Same osmolarity at equilibrium

Question 9

To maintain equality

Answer 9

Water shifts between compartments

Question 10

Electrolytes (Na+)

Answer 10

Do not cross cell membranes

Confined to ECF

Question 11

Any loss or gain of water and/or electrolytes must initially occur where?

Answer 11

ECF

Question 12

What are three things that can be measured that will give information about current hydration status of a patient?

Answer 12

Total body water

Total plasma protein

Hematocrit

Question 13

Hematocrit

Answer 13

Percentage of plasma that is taken up by red blood cells

=height RBCs/total height

Question 14

Changes in ECF causes what changes in hematocrit?

Answer 14

Dilution

Concentration

Question 15

Changes in ICF cause RBCs to?

Answer 15

Swell or shrink

Question 16

Changes in both ECF and ICF have what effect on hematocrit?

Answer 16

Additive and cancelling effects

Question 17

What happens when you gain an isotonic fluid?

Answer 17

Isosmotic volume expansion

Question 18

What happens when you lose an isotonic solution?

Answer 18

Isosmotic volume contraction

Question 19

What happens when you gain a hypotonic solution?

Answer 19

Hypotonic volume expansion

Question 20

What happens when you lose a hypotonic solution?

Answer 20

Hyperosmotic volume contraction

Question 21

What happens when you gain sodium?

Answer 21

Hyperosmotic volume expansion

Question 22

What happens when you lose sodium?

Answer 22

Hyposmotic volume contraction

Question 23

What happens when you infuse isotonic glucose?

Answer 23

Hypotonic volume expansion

Question 24

Body fluid shifts that cause volume contraction?

Answer 24

Diarrhea
Water deprivation
Aldosterone insufficiency

Question 25

Body fluid shifts that cause volume expansion?

Answer 25

Infusion of isotonic NaCl
Higher NaCl intake
Pure water intake

Question 26

Isosmotic means

Answer 26

No change in osmolarity of ECF

Question 27

Hyperosmotic means

Answer 27

Increase in osmolarity of ECF

Question 28

Hyposmotic means

Answer 28

Decrease in osmolarity of ECF