Body Fluid Compartments

Question 1

Extracellular Fluid - what does it provide?

Answer 1

(blood plasma and interstitial fluid)
- Moderates effects of external environment
- Provides optimum conditions for cellular activities

Question 2

What is osmoconformers

Answer 2

Maintain osmotic concentration of extracellular fluids similar to environment
- most marine invertebrates, hagfish and chondrichthyes

Question 3

What is osmoregulators

Answer 3

Maintain osmotic concentration of extracellular fluids different from environment
- measure of how many solutes
- ATP or energy is required
- marine vertebrates - all freshwater animals

Question 4

what is ionorgulators

Answer 4

maintain extracellular concentration of specific ion(s) different from environment
- all animals regulate at least one ion
- ATP required

Question 5

What are the major extracellular solutes

Answer 5

Inorganic ions (mostly Na+ and Cl-)

Question 6

What are the major intracellular solutes

Answer 6

More organic solutes (amino acids, proteins, etc.)
- fewer inorganic ions
-Mostly K+ instead of Na+

Question 7

Why do some animals purposefully put urea into their extracellular fluid?

Answer 7

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.

Question 8

Why do these animals use urea?

Answer 8

-permeable to membrane
-flows very easily
- not very toxic
- abundant
- easily made

Question 9

Why is the osmotic concentration of the ECF and ICF generally similar in all animals?

Answer 9

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

Question 10

How can you tell on a graph if an animal is an osmoconformer or regulator?

Answer 10

on a graph the osmoconformers are much taller than regulators, they reach almost 1200 mM where as regulator reach barely 400 mM

Question 11

is Na+ outside or inside?
Is K+ outside or inside?

Answer 11

Na+ is outside the cell,
K+ is inside

Question 12

Why is K+ the major intracellular ion?
Why not Na+

Answer 12

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

Question 13

Which is smaller Na or K

Answer 13

Na is smaller

Question 14

What charge does Na and K have

Answer 14

+1

Question 15

Which ion has a higher charge density in its surface

Answer 15

Na since it is smaller in size with the same charge

Question 16

Which ion will attract more H20

Answer 16

Na will attract more H20 and have a larger more structured hydration sphere
- reacts as a bigger ion than it is

Question 17

What type of diffusion is the most common

Answer 17

most of this water movement is actually by SIMPLE DIFFUSION

Question 18

What is simple diffusion

Answer 18

process by which molecules and alter particles move from an area of high concentration to an area of low concentration through random kinetic motion

Question 19

At temperature greater than absolute zero, molecules move….

Answer 19

in random directions at high velocity and undergo perfectly elastic collisions

Question 20

why does temperature influence diffusion?

Answer 20

because collisions generate heat
- movement will continue as long as temp stays above absolute 0

Question 20

what is flux of a substance?

Answer 20

flow rate per area - a substance during diffusion

Question 21

flux of a substance is determined by what (6)

Answer 21

1. Magnitude of concentration gradient
2. temp
3. Mass of solute
4. charge of solute
5. other chemical features of solute
6. type of solute

Question 22

what is the diffusion coefficient

Answer 22

D in units of m^2/sec

Question 22

what is ficks equation for a planar surface

Answer 22

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

Question 23

what is the most common form of movement?

Answer 23

Diffusion

Question 24

what can be done to optimize diffusion flux?

Answer 24

increase length = decrease flux
so keep length short
Concentration gradient can be increased by increasing concentration on one side

Question 25

is diffusion a slow or quick process?

Answer 25

slow, distance matters

Question 26

what is liquid junction potential

Answer 26

temporary electrical potential established when two different ionic solutions are first brought in contact with each other

Question 27

mass influences diffusion rates
Which is smaller Hydrogen or potassium

Answer 27

hydrogen is smaller than potassium

Question 28

when does Lipid junction potential disappear

Answer 28

it is temporary and will disappear at equilibrium

Question 29

other cases where diffusion potentials continue to exist after equilibrium is reached is called

Answer 29

equilibrium potentials

Question 30

what equation can be used to predict the theoretical size of all potentials?

Answer 30

the nernst equation

Question 31

what is the nernst equation?

Answer 31

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