Ventillation And Gas Exchange In Fish Flashcards
2 reasons why fish need specialised exchange surfaces
They have a small surface area to volume ratio
Impermeable membrane so gases cannot enter their skin through diffusion
What does gill filament do
Increase surface area for diffusion
What does gill lamelae do
Create a large surface area to volume ratio
What does the capillary network do
Creates a short diffusion distance due to the capillary network in every lamellae and every thing gill lamelae
What does the counter current flow do
Maintains the concentration gradient
Describe the counter current flow
When water flows over the gils in opposite directions to the flow of blood in the capillaries
It ensures that equillibrium is not reached
Ensures that a diffusion gradient is maintained across the whole length of the gill lamelae
