Body Fluid Compartments

Question 1

compartments of the extracellular fluid

Answer 1

plasma and interstitial fluid

Question 2

major cation of the ECF, plasma and interstitial fluid

Answer 2

Sodium

Question 3

major cation of the ICF

Answer 3

potassiuim

Question 4

major anion of ECF (plasma and interstitial)

Answer 4

Cl

Question 5

Major anion of the ICF

Answer 5

phosophates, protein

Question 6

membranes are impermeable to ______, so they normally do not impact osmolarity. However, they do exert _________

Answer 6

impermeable to proteins
but exert oncotic (colloid osmotic) pressure: pressure generated by large molecules (like proteins) in solution that are impermeable to membranes

Question 7

ECF can be measured using these indicators

Answer 7

22Na+, l-iothalamate, thiosulfate

INULIN

Question 8

TBW can be measured using these indicators

Answer 8

3H2O, 2H2O, antipyrine

Question 9

ICF cannot be measured using an indicator but it can be calculated by

Answer 9

TBW - ECF = ICF

Question 10

Plasma volume can be measured with these indicators

Answer 10

l-albumin, Evans blue dye

Question 11

interstitial fluid cannot be measured using an indicator, but can be calculated by

Answer 11

ECF - plasma = ISF

Question 12

albumin can be used to measure plasma volume because

Answer 12

it should not cross plasma membranes

Question 13

two compartments that arent measured directly

Answer 13

ICF and ISF

Question 14

Na and K concentration is slightly _____ than expected in the vascular space due to what effect

Answer 14

slightly higher than expected due to Gibbs-donnan effect - negative charge of proteins within the vasculature attracting positively charged Na and K ions

= 290 mOsm

Question 15

ECF osmolality is driven by

Answer 15

1) Na and Cl

2) Na vasculature > Na interstitial > Na ICF due to action of NA-K ATPase pump

Question 16

ICF osmolality is driven by

Answer 16

K

Question 17

Equation for plasma osmolality

Answer 17

= 2(Na) + Glucose/18 + urea/2.8

Question 18

ECF and ICF are highly permeable to ______ but not permeable to most ______

Answer 18

water

electrolytes

Question 19

Pc stands for the

Answer 19

hydrostatic pressure within the lumen of a capillary

force promoting movement of fluid from lumen to interstitium

Question 20

factors that will increase Pc

Answer 20

increased arterial pressure
Increased venous pressure
decreased precapillary resistance
Increased postcapillary resistance

Question 21

Pi stands for

Answer 21

hydrostatic pressure within the interstitium

promotes fluid in the lumen to remain in the lumen

Question 22

Pic stands for

Answer 22

oncotic (colloid osmotic) pressure within the capillary

discourages movement of fluid out of the lumen

Question 23

Pi i stands for

Answer 23

oncotic (colloid osmotic) pressure within the interstitium

Promotes movement of fluid out of the lumen

Question 24

osmolality of the _____ controls volume of the _____

Answer 24

ECF osmolality controls ICF volume

Question 25

All water and solutes must pass through the ____ first

Answer 25

ECF

Question 26

causes of edema

Answer 26

abnormal leakage of fluid from plasma to the interstitial spaces across the capillaires
or
failure of lymphatic to return fluid from the interstitium back to the blood

Question 27

congestive heart failure scenario

Answer 27

movement of fluid from intravascular space to interstitial space decreases ECV
Udnerfilled vasculature stimulates compensatory response renal mechanisms
Na and water retention
Restores perfusion pressure but exacerbates edema

Question 28

primary renal disease scenario

Answer 28

inappropriate renal retention of sodium and water overfills vascular tree

1. volume expanison, elevates blood pressure
2. increases hydrostatic pressure while decreasing plasma oncotic pressure