Water & regulation of extra/intracellular fluids
Nutrition 6106 with Ganji at Georgia State University
About this deck
By: Nikki Speake
Created: 2011-02-05
Size: 38 flashcards
Views: 14
Created: 2011-02-05
Size: 38 flashcards
Views: 14
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Interstitial Fluid
Solution that bathes & surrounds cells of multicellular animals. The main component of extracellular fluid, which includes plasma & transcellular fluid. Found in interstitial spaces, also known as the tissue spaces.
Extravascular
Fluid just outside the blood vessels. (Eye, CSF, mucus, gastric juices
Osmolarity (vol)
- is a measure of solute conc. defined as number of osmoles of solute per liter of solution (osmol/L) –temp. dependent (if temp goes up, volume expands)
- 1 osmole/L
- specific for molecules exerting osmotic pressure
Osmolality (wt)
- is a measure of the osmoles of solute per kilogram of solvent
- not temp dependent (because weight is not temp dependent)
Aquaporins
proteins embedded in the cell membrane that regulate the flow of water
Solute
What is dissolved in water (Solvent): Salt, NaCl, K, phosphate buffers, bicarb buffers.
All contribute to molarity, osmolarity, and [solute].
Molarity
(M) concentration expressed as moles of solute per L of solution.
the M of molarity means:
moles/L, NOT simply moles
Molarity is often expressed as (units):
millimolar (mM) = 10-3 M, micromolar (mM) = 10-6 M, nanomolar (nM) = 10-9 M, or picomolar (pM) = 10-12 M
Molality
concentration expressed as per kg of solvent
When are osmolarity & osmolality considered equivalent?
if the concentration of solute is very low
1 osmole =
1 mole/L of osmotically active particles
1 mole = 1 g of molecular weight.
1 mole/L of NaCL =
2 osmoles/L (but would still be one mole)
One dissociated in the water, you get Na+ Cl- (each molecule is one osmole)
Osmole: osmotically active particles
TBW (L) =
Body Wt. (lb)/4
Intracellular Fluid comprises (ICF):
- ~60% (24L), the major portion of your body water.
- inside the cell
ICF is __% of total body weight
40% of total body weight
What are the constituents of ICF?
Not homogeneous, but consist of K, organic anions, and proteins.
It is a conglomeration of fluids from all the body's cells
What controls the constituents of ICF?
cell membranes and cell metabolism
Extracelluar Fluid (ECF)
The other 40% (16L) of the body's water, 20% of total body weight
ECF primarily consists of:
Na and NaHCO3 solution. (bicarbonate)
osmotically active particles
3 sub-compartments of ECF:
- Interstitial fluid (ISF)
- Plasma
- Transcellular fluid
Interstitial fluid
- surrounds the cells, but does not circulate
- comprises about 28% (11.2L) of the total body fluid
Plasma
- intravascular fluid, circulates as the extracelluar component of blood
- makes up 8% of (3.2L) of total body fluid
- hydration goes up /dehydration goes down
- most important with kidney fx and water homeostasis
- cardiac output
Transcellular fluid
- set of fluids outside the normal compartments
- 1-2 L of fluid
- CSF, digestive juices, mucus, 4% of total body fluid
Three measurable volumes of water
- Total Body Water (TBW)
- ECF volume
- Plasma volume
How TBW is measured
- Use D20 (deuterated water) or radioactive water, Distributes throughout all aqueous solutions. radioactive shows up everywhere
How ECF volume is measured
Use radioactive Inulin (Stable Isotope) fructo-oligosaccharide
-Distribute throughout body, but are excluded from cells
only stays in extracelluar fluid.
How plasma volume is measured
Use radioactive albumin, stays in plasma only.
Interstitial volume =
ECF volume - plasma volume
Intracellular volume =
Total Body water - ECF volume
Gram Molecular Weight (GMW)
The number of grams of a substance it takes to provide a mole (mol) of that substance
- (i.e., 6.02x1023 molecules)
The GMW of a molecule can be calculated by:
summing the atomic weight of its individual atoms
Electrochemical Equivalence (Eq)
Applies to salts that dissociate into ions, how much it takes to neutralize electrochemical potential
An "equivalent" is
- the weight in grams (mole) of an ionic substance that replaces or combines with one gram (mole) of monovalent H+ ions.
monovalent ions (equivalent):
(Na+, Cl-) 1 Eq = 1 GMW
divalent ions (equivalent):
- (Ca+2, Mg+2, HPO4-2) 1 Eq = ½ of a GMW
- Physiological concentrations are often measured in
- mEq/L = 10-3 Eq/L. These units are useful when considering how much of a substance is needed to maintain electroneutrality.
- (food & drink) 2.2L/day
- (skin & lungs) 0.9L/day
- (metabolism) 0.3L/day
- (urine) 1.5L/day
- (feces) 0.1L/day
- Glucose + O2 -> CO2 + H20 + ATP
- 2.2
- 0.3
- 0.9 + 0.1 + 1.5
About this deck
By: Nikki Speake
Created: 2011-02-05
Size: 38 flashcards
Views: 14
Created: 2011-02-05
Size: 38 flashcards
Views: 14
About StudyBlue
STUDYBLUE makes things that make you better at school.
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Things like personalized quizzes and friendly reminders about when (and what) to study next.
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