Gas exchange in fish Flashcards
why are fish waterproof?
scales
what size fishes surface area to volume ratio ?
small
what is a fish gas exchange surface?
gills
where do fish get their oxygen from ?
water
what is ficks law ?
diffusion =(surface area X diffrence in concentration )/ length of diffusion pathway
how many layers of gills are in both sides of head ?
4
what are gills made up of ?
stacks of gill filaments
what is each gill filament covered in ?
gill lamellae positioned at right angles from filaments
what do gill lamellae allow ?
large surface area . short diffusion pathway by a capillary network in every lamellae and them being very thin
what happens when fish opens their mouth ?
water flows in and over the gills then out through a hole in their side of head
how do fish maintain a concentration gradient ?
countercurrent flow mechanism
how does the countercurrent exchange system work ?
water flows over the gills in opposite direction of blood in capillaries
ensures equilibrium is not reached
so diffusion gradient is maintained along entire length of the gill lamellae
