Gaseous Exchange In Bony Fish Flashcards
What is the structure of the gills
The gill consists of a series of bony gill arches each with two stacks of gill filaments
What is the structure of the gill filaments
Gill filaments have protruding rows of very thin lamellae
What is the structure of a lamellae
Each lamellae consists of a network of capillaries covered by a single layer of epithelial cells
What protects the gill structures
A bony plate called an operculum
Why do fish need to ventilate their gills
To maintain a strong diffusion gradient for efficient exchange
How do fish ventilate their gills
Fish coordinate the opening of the opercular vents with the closing of the buccal cavity
What is the buccal cavity
The technical term for a fishes mouth
How do fish pump water over their gills
When they open their buccal cavity they close their opercular vents to draw freshwater in which can be pumped over the gills
How do fish enable counter current flow
The orientation of the gill filaments and lanellae ensures that the water flowing over then moves counter current to the flow of the blood through the capillaries
What is counter current flow
Two liquids in close proximity flowing in opposite directions
How does oxygen diffuse from water
As water flows past the capillaries it loses oxygen to the blood down a diffusion gradient
Why does diffusion occur
Blood that has very little oxygen flows past water with some oxygen so diffusion occurs
