gas exchange in fish (module 3) Flashcards
1
Q
how does fish allow gas exchange to occur
A
- fish opens mouth water passes over lamellae and oxygen diffuses into bloodstream
- waste products like CO2 diffuse into water and flow back out
2
Q
why is parallel flow not used in fish?
A
- blood and water flow in same direction so eventually reach equilibrium
- so concentration is not maintained along whole length of lamellae
3
Q
why does the countercurrent flow allow efficient gas exchange?
A
- blood and water flow in opposite directions along lamellae
- maintains concentration gradient
- along WHOLE LENGTH of lamellae
4
Q
how does ficks law apply to fish?
A
- large surface area provided by many gills which are covered by many gill lamellae
- countercurrent flow which maintains concentration gradient along lamellae
- short diffusion distance as epithelia and capillary walls one cell thick