6.4 - Gas Exchange in Fish Flashcards
The challenges bony fish face in extracting oxygen from water The structure and function of fish gills for gas exchange The countercurrent exchange system in fish gills (11 cards)
Why do bony fish need specialised respiratory systems? Check
High oxygen needs
What are some challenges of oxygen uptake in water?
- Water is denser and more viscous than air, resulting in slower diffusion of oxygen.
- Water has less oxygen than air.
- Bony fish are very active so have high oxygen demands.
What structures allow bony fish to efficiently take up oxygen?
Gills
What covers the gills?
Operculum flap
What do gills consist of?
Stacked filaments containing gill lamellae
What surrounds gill lamellae?
Extensive blood vessels
What are adaptations of gills for efficient gas exchange? Check
Large surface area
What is countercurrent flow?
Blood and water flow in opposite directions
Why is countercurrent flow efficient? Check
Maximizes oxygen diffusion
What happens in parallel flow?
Blood and water flow in the same direction
Why is countercurrent exchange more efficient than parallel flow?
Maintains a steeper concentration gradient
