Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
42 Cards in this Set
- Front
- Back
|
TBW is what % of body weight kg?
|
60%
|
|
|
Who would have a higher TBW, males and infants, or females and old people?
|
MALES and INFANTS
|
|
|
Why does TBW decrease w/ age and in females?
|
More body fat = less body water
|
|
|
2 places where TBW is distributed, how much?
|
-ECF 1/3
-ICF 2/3 |
|
|
What is EXTRAcell fluid distributed between?
|
25% plasma
75% interstitium |
|
|
What are the major cations/anions in ECF?
|
-Na
-Cl -HCO3 |
|
|
What fraction of TBW is PLASMA?
|
1/12 (1/4x1/3)
|
|
|
What fraction of TBW is interstitial fluid?
|
1/4 (3/4x1/3)
|
|
|
What are the major plasma proteins?
|
Albumin and Globulins
|
|
|
How is interstitial fluid different from plasma?
|
No proteins, it's an ultrafiltrate of plasma.
|
|
|
What are the major cations/anions of INTRAcell fluid?
|
-K
-Mg2+ Protein Organic phosphates (ATP/ADP/AMP) |
|
|
60-40-20 rule:
|
% of body weight:
TBW is 60% ICF is 40% ECF is 20% |
|
|
2 Markers used to measure TBW:
|
-Tritiated water
-Heavy water |
|
|
3 markers to measure ECF:
|
-Sulfate
-Inulin -Mannitol |
|
|
2 Markers to measure Plasma:
|
RISA - radiolabeled serum Albumin
Evans blue |
|
|
How do you measure ISF?
|
Indirectly
ECF - Plasma |
|
|
How do you measure ICF?
|
Indirectly
TBW - ECF |
|
|
How do you go about measuring fluid compartment volumes?
|
Inject a substance that has a Vd that you know is the compartment of interest
|
|
|
So how would you measure ECF?
|
Inject Sulfate, inulin or Mannitol - they're too big to cross plasma membranes; allow it to equilibrate, then measure the Concentration.
|
|
|
How do you determine VOL?
|
You know C1V1, measure C2, figure out V2
|
|
|
What is the osmolarity of our CELLS and the fluid surrounding them at steady state?
|
EQUAL
|
|
|
How is isosmoticity achieved?
|
By fluid shifts, but no shifts of NaCl or mannitol
|
|
|
What will happen to body water compartments if you infuse isotonic saline?
|
ECF will increase due to the adding of Volume, but no fluid will shift - it's isotonic
|
|
|
What are 4 changes you'll see as a result of infusing isotonic saline?
|
-Increase ECF
-Increase Mean arterial Pressure -Decrease Serum Protein conc -Decrease Hematocrit |
|
|
Will RBC size change by infusing isotonic saline?
|
NO
|
|
|
What are 4 changes that will occur in cholera diarrhea?
|
1. Decrease ECF
2. Decrease MAP 3. Increase Serum Protein conc 4. Increase Hematocrit |
|
|
Why does Cholera diarrhea only decrease the ECF volume?
|
It is isosmotic diarrhea - so you only lose water, not solutes
|
|
|
What will happen in excessive NaCl intake?
|
Hypertonic volume expansion of the ECF
|
|
|
Why does ECF vol expand when you eat a lot of salt?
|
Because it increases the ECF osmolarity so water shifts from inside cells to ECF.
|
|
|
What is the resulting osmolarity of ICF/ECF after the fluid shift from ICF to ECF in excessive salt intake?
|
They both equilibrate at a higher osmolarity
|
|
|
How will plasma protein and Hct change in excessive salt intake?
|
Both DECREASE - due to the increased ECF volume.
|
|
|
When you SWEAT, what are you mainly losing and why?
|
Water - because the body has mechanisms to prevent losing salt in sweat.
|
|
|
What happens to body fluid when you sweat excessively then?
|
-Decrease ECF vol, increase Osm
-Fluid shifts from ICF to where the solutes are |
|
|
So what are the overall results of excessive sweating?
|
1. Decrease ECF vol, increase Osm
2. Decrease ICF vol, increase osm 3. Increase protein conc |
|
|
What happens to hematocrit in excessive sweating?
|
NOTHING - though the ECF vol is decreased, water shifts out of RBCs so they shrink and volume decreases in them too.
|
|
|
What happens to body fluid compartments in siADH?
|
Both ICF/ECF vol increase, both osmolarities decrease
|
|
|
Why do we see these changes in siADH?
|
ADH only increases water reabsorption, not Na.
|
|
|
What happens to protein conc and hematocrit in siADH?
|
Protein conc decreases but Hct remains the same bc the cells now swell in response to low serum osmolarity
|
|
|
What is the main effect on body fluid compartments in adrenal insufficiency like Addison's?
|
LOSS of NaCl (fail to retain it)
|
|
|
What happens to body fluid compartments in adrenal insufficiency?
|
ECF vol decreases and becomes hypoosmotic; fluid shifts from ECF to ICF (where solute is) so ICF vol INcreases; both equilibrate as hypoosmotic.
|
|
|
What happens to plasma protein conc and hct in adrenal insufficiency?
|
Both concentrations increase and the Hct increases because cells swell in hyposmotic ECF.
|
|
|
What will happen to MAP in adrenal insufficiency
|
DECREASE - decreased ECF vol
|
