Gas exchange in bony fish Flashcards
1
Q
Why do bony fish have adaptations to their gas exchange system?
A
- Water has less oxygen than air meaning its harder to extract oxygen from water
- Water is denser than air so diffusion is slower
- Bony fish are very active so have high oxygen demands
2
Q
Where does gas exchange for bony fish take place?
A
The gills
3
Q
Where does diffusion of gas take place?
A
On the gill lamellae
4
Q
Describe the structure of the gills
A
- The gills are made up of stacks of gill filaments
- Each gill is covered in gill lamellae
5
Q
What are the 3 adaptations of gills that ensure efficient gas exchange?
A
- Many gill filaments covered in many gill lamellae which creates a large surface area
- Lamellae are very thin and contain capillary networks so has a shorter gas diffusion distance
- Countercurrent flow of blood and water maintains a concentration gradient of oxygen across the length of the gill lamellae
6
Q
What is the countercurrent flow mechanism?
A
Where blood and water flow in opposite directions over the lamellae which maintains a concentration gradient of oxygen across the entire length of the gill lamellae
- This ensures that equilibrium is not reached
