Osmoregulation Flashcards
Osmoregulation
Process by which internal water and solute concentration are maintained despite fluctuations in the external environment
Hypertonic
the cell has a higher solute(salt) concentration then the surrounding solution, the water particles move out of the cell causing the cell to shrink
Hypotonic
the cell has a lower solute (salt)concentration then the surrounding solution, the water particles move into the cell causing it to expand
Isotonic
the cell has the same solute (salt ) concentration as the surrounding solution therefore there is no net movement of water and the concentration remains constant
Osmoconformers
- organisms whose body fluids fluctuate with the changing environment they are in
- jelly fish
- cannot regulate salt and water balances
Osmoregulators
- organisms that expend energy to maintain constant salt and water concentrations despite changes in the external environment
- mammals and fish
Osmoregulation in salt water fish
Problem: hypertonic water, body fluid is hypotonic
- water loss from gills and skin
- salt invasion via gills
- blood has higher water concentration then the sea
- must replace the water which they lose by osmosis
Solution: drink a lot of salty water to get water
- excrete little but concentrated urine
- active transport salt out from the blood into the water
Fighting to keep water and get rid of salt because salt continuously enters
Osmoregulation in fresh water fish
Problem: hypotonic water, body fluid is hypertonic
- blood has lower concentration then the water
- water enters gills and skin by osmosis
- salt loss from gills
Solution: don’t drink
- excrete lots of dilute urine, reabsorb salt in nephrons
- active uptake of salt in gills
- eat salty food
Fighting to keep salt and get rid of water because water countinuously enters
Cartilage salt water fish
Sharks and rays reabsorb urea from nephrons
- blood is isotonic to seawater
- don’t need to do anything
