Exchanging Surfaces In The Fish Flashcards
Why does the levels of saturated oxygen have to be higher in the water than the blood?
oxygen needs to flow from an area of high conc. to an area of low conc.
What does a countercurrent flow system mean?
The oxygenated and deoxygenated blood constantly flow in opposite directions
What is the operculum?
The technical term for a gill cover
Describe how the buccal/ opercular pump maintains the flow of oxygenated water over the gills in a bony fish?(4marks)
•Floor of the mouth moves downwards
•Meaning buccal cavity expands (inc vol)
•Mouth closes pushing water back towards the gills
•Operculum moves outwards (inc pre)
•The oxygenated water flows with the pressure of the conc gradient through the gills.
How do fish maximise the amount of oxygen they can pick up?
•Maintains a steep concentration gradient as water is always next to blood with a lower oxygen conc
•This keeps rate of diffusion constant and enables 80% of available oxygen to be absorbed
What is meant by a concurrent flow system?
the low-oxygen blood entering the gill would first meet the high-oxygen water also entering the gill
Where does the different levels of oxygenated blood travel through?
•High oxygenated water with high oxygenated blood
•Low oxygenated water with low oxygenated blood
As the conc is always higher in the water it means that oxygen can flow from water to blood
How is the gill adapted to its function?
•large surface area (lamellae)
•good blood supply
•maintains a diffusion gradient
•short distance between the blood and the water
What’s the function of a gills rake?
aid in the gathering of food and protection of the gills
What is the function of a gills lamellae?
to increase the surface area in contact with the environment to maximize gas exchange. Blood and water flow in opposite directions across them
What is the function of the gills filaments?
provide blood with oxygen by taking oxygen from the water
What is the function of the gills arch?
are the structural component of the gill
Why do fish need adaptations?
They have a small SA:V ratio and they have an impermeable membrane meaning gasses can’t diffuse through their skin
How many pairs of gills does a bony fish have?
Four
Why can’t fish survive very long out of water?
Due to their gills being separated by water meaning they can’t breathe in the absence of it
