Osmosis, Tonicity, and Pressures

t/f osmosis is simply the diffusion of water

FALSE!! It occurs because of the pressure difference

semipermeable membrane is permeable to ____ but not permeable to ____

solvent; solute

(water moves, solute cannot)

osmotic pressure

PULLING PRESSURE!

Created by difference in solute concentration across membrane

t/f osmotic pressure refers to amount of hydrostatic pressure required to stop osmosis

true

hydrostatic pressure

PUSHING PRESSURE!

pressure exerted by stationary fluid causing fluid to move

more fluid=

more pressure to move

*create driving force

which pressure is generally dominant

blood hydrostatic

interstitial hydrostatic

exerted by fluids between cells in tissue

blood hydrostatic

exerted by fluid within blood vessels

-----> really high!

t/f hydrostatic pressure opposes osmotic pressure

true

t/f high osmolarity exert low osmotic pressure to pull water into a space

false, exert high osmotic pressure

osmolar concentrations express

osmotic strength

osmolarity

[ ] of osmotically active particles/ L of solution

osmolality

[ ] osmotically active particles expressed as omoles/kg water (~1L)

t/f osmolarity and osmolality are functionally the same

true

isosmotic

solutions of equal solute [ ]

what happens to normal cell placed in isosmotic solution

nothing

hyperosmotic

solution with higher concentration of solute

solution exerts more pressure

what happens to normal cell placed in hyperosmotic solution

water moves from cell-> solution

cell shrinks !

hypoosmotic

solution with lower concentration of solute

solution exerts less pressure

what happens to normal cell placed in hypoosmotic solution

water moves into cell from solution

cell explodes !

tissue tone

measure effective osmotic pressure

tonicity

response of cells or tissues immersed in solution

isotonic solutions will

neither shrink nor swell cell

t/f there is no osmotic difference between cell interior and extracellular for isontonic

true

hypotonic solution will

cell/ tissue swell when immersed in solution

Are there more solutes inside or outside the cell relative to extracellular environment for hypotonic?

`more solutes inside the cell, greater osmotic pressure inside the cell

hypertonic solution will

cause cell/tissue to shrink when immersed in solution

Are there more solutes inside or outside the cell relative to extracellular environment for hypertonic?

less solutes inside the cell, greater osmotic pressure outside the cell

names for osmotic pressure

colloid osmotic pressure

oncotic pressure **

t/f there is a form of osmotic pressure specifically exerted by proteins, within blood vessels

true

what proteins exert osmotic pressure

albumin mostly

does oncotic pressure tend to pull water into blood vessels?

yes

what pressure does oncotic pressure oppose?

interstitial colloidal osmotic pressure

edema occurs when

there is a decrease in blood oncotic pressure