Body Fluid Compartments Flashcards
Extracellular Fluid - what does it provide?
(blood plasma and interstitial fluid)
- Moderates effects of external environment
- Provides optimum conditions for cellular activities
What is osmoconformers
Maintain osmotic concentration of extracellular fluids similar to environment
- most marine invertebrates, hagfish and chondrichthyes
What is osmoregulators
Maintain osmotic concentration of extracellular fluids different from environment
- measure of how many solutes
- ATP or energy is required
- marine vertebrates - all freshwater animals
what is ionorgulators
maintain extracellular concentration of specific ion(s) different from environment
- all animals regulate at least one ion
- ATP required
What are the major extracellular solutes
Inorganic ions (mostly Na+ and Cl-)
What are the major intracellular solutes
More organic solutes (amino acids, proteins, etc.)
- fewer inorganic ions
-Mostly K+ instead of Na+
Why do some animals purposefully put urea into their extracellular fluid?
These animals are osmoregulators trying to be osmoconformers in order to save energy, so they put urea into their extracellular fluid since it lessens the sodium intake when going into water to hunt for food.
Why do these animals use urea?
-permeable to membrane
-flows very easily
- not very toxic
- abundant
- easily made
Why is the osmotic concentration of the ECF and ICF generally similar in all animals?
Osmotic equilibrium
- extracellular and intracellular concentration must be fairly equal or else the cell could explode by becoming too hypotonic
- bulk water moves across most easily
- pulling out the free water or bulk water
- cells cant really control water movements
How can you tell on a graph if an animal is an osmoconformer or regulator?
on a graph the osmoconformers are much taller than regulators, they reach almost 1200 mM where as regulator reach barely 400 mM
is Na+ outside or inside?
Is K+ outside or inside?
Na+ is outside the cell,
K+ is inside
Why is K+ the major intracellular ion?
Why not Na+
Hydration spheres! - It is a better Cation - they react differently to H20
- more bound water
- need more bulk water
- with more water, need more cells
- cells can only get so big while being structurally sound
Which is smaller Na or K
Na is smaller
What charge does Na and K have
+1
Which ion has a higher charge density in its surface
Na since it is smaller in size with the same charge
Which ion will attract more H20
Na will attract more H20 and have a larger more structured hydration sphere
- reacts as a bigger ion than it is
What type of diffusion is the most common
most of this water movement is actually by SIMPLE DIFFUSION
What is simple diffusion
process by which molecules and alter particles move from an area of high concentration to an area of low concentration through random kinetic motion
At temperature greater than absolute zero, molecules move….
in random directions at high velocity and undergo perfectly elastic collisions
why does temperature influence diffusion?
because collisions generate heat
- movement will continue as long as temp stays above absolute 0
what is flux of a substance?
flow rate per area - a substance during diffusion
flux of a substance is determined by what (6)
- Magnitude of concentration gradient
- temp
- Mass of solute
- charge of solute
- other chemical features of solute
- type of solute
what is the diffusion coefficient
D in units of m^2/sec
what is ficks equation for a planar surface
J = D [(C1-C2)/X]
J= flux amount of substance per unit area
D= diffusion coefficient area per time (m^2/sec)
C1-C2 = concentration gradient
amount of substance/volume (m^3) of solvent
x= length (m)
by convention c1>c2 - a negative diffusion doesnt make sense
what is the most common form of movement?
Diffusion
what can be done to optimize diffusion flux?
increase length = decrease flux
so keep length short
Concentration gradient can be increased by increasing concentration on one side
is diffusion a slow or quick process?
slow, distance matters
what is liquid junction potential
temporary electrical potential established when two different ionic solutions are first brought in contact with each other
mass influences diffusion rates
Which is smaller Hydrogen or potassium
hydrogen is smaller than potassium
when does Lipid junction potential disappear
it is temporary and will disappear at equilibrium
other cases where diffusion potentials continue to exist after equilibrium is reached is called
equilibrium potentials
what equation can be used to predict the theoretical size of all potentials?
the nernst equation
what is the nernst equation?
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