Topic 3 - Gas Exchange In Fish [11] Flashcards
How can Rate of Diffusion be calculated?
Fick’s Law.
Diffusion = Surface Area x Difference in Concentration
—————————————————————-
Length of Diffusion path
What are the 3 features of an efficient gas exchange surface?
Large Surface Area to Volume Ratio
Short Diffusion Pathway
Maintaining A Concentration Gradient
Why do fish require a gas exchange surface?
Fish are waterproof
they have a small SA : V ratio
Fish have a short diffusion distance for efficient gas exchange, Explain.
Fish have a capillary network in EVERY SINGLE Lamellae, The Lamellae are THIN.
Describe the Countercurrent Flow Mechanism
when the water flow in the gills in the opposite direction to the flow of blood in capillaries.
It ensures equilibrium is never reached, meaning diffusion can occur across the entire length of the lamellae.
How do Fish Maintain Concentration Gradient for efficient gas exchange?
Countercurrent Flow Mechanism
Fish have A Large SA : V Ratio for efficient gas exchange, how?
Fish have many GILL FILAMENTS covered in many GILL LAMELLAE
Describe the Fish Gill Anatomy
FOUR Layers of Gills on both sides of the head
Gills made up of stacks of gill filaments
each gill filament covered in gill lamellae (positioned at right angles to the filament)
This creates a large SA
When fish open their mouth
water rushes in over the gills and then out through holes in the sides of their head
How can Rate of Diffusion be calculated?
Fick’s Law.
Diffusion = Surface Area x Difference in Concentration
—————————————————————-
Length of Diffusion Path
Describe the Countercurrent Flow Mechanism
when the water flow in the gills in the opposite direction to the flow of blood in capillaries.
It ensures equilibrium is never reached, meaning diffusion can occur across the entire length of the lamellae.
