Water Balance Flashcards
What is osmoregulation?
Process that balances the uptake and loss of water
Under homeostatic control
What influences passive rate?
Higher temperatures
Smaller particles
Electrical ion charge
Greater gradient
What is osmolarity?
Concentration of a solution expressed as the total number of solute particles per litre of solution
SIMPLE TERMS:
Number of osmoses of solute per litre of solution
What is osmolarity measured in?
Osmoses/litres (Osm/l)
What animals tend to be osmoregulators?
Terrestrial animals
What is tonicity?
Effect of a solution on cell volume?
What does tonicity depend on?
Solutes and membrane’s permeability
How are marine teleost adapted to obtain large amounts of drinking water in high ion concentrated water?
Drinks seawater
Active extrusion of ions
Releases small amounts of concentrated urine
How do marine teleost get rid of salt?
Sodium ions build up in extracellular fluid to create a concentration gradient
Sodium ions move down the concentration gradient and move back into the cell (bringing chlorine ions with them) via the Na/Cl symporter
Sodium ions are pumped back out of cell to keep a low concentration gradient
Chlorine ions build up inside the cell
Chlorine ions move down the concentration gradient and moves passively out of the cell
A positive charge forms at the basolateral membrane and a negative charge forms at apical
Charge gradient allows sodium ions to be pulled out of the cell through gaps between cells and out of the organism
How are freshwater telost adapted to obtaining ions?
Active transport of ions into gills
Release large amounts of dilute urine
How are freshwater telost gills adapted to obtain ions?
Super high affinity sodium and chlorine ion transporters bring ions into the cells
Na/K ATPase pumps sodium ions into cells
Lots of mitochondria to provide energy for pumps
