Gas Exchange To Learn

Question 1

One feature of alveoli epithelium that makes the epithelium wall adapted for gas exchange

Answer 1

Single layer of cells
Reduces diffusion pathway
Permeable
Allows diffusion of oxygen/carbon dioxide

Question 2

How does a reduced tidal volume affect the exchange of carbon dioxide between blood and alveoli?

Answer 2

Less carbon dioxide exhaled out of lungs
Reduced diffusion/concentration gradient bewteeen blood and alveoli
Slower movement of carbon dioxide out of the blood so more remains in the blood

Question 3

Describe the mechanism that causes lungs to fill with air

Answer 3

Diaphragm contracts and external intercostal muscles contract
Causes volume to increase and pressure to decrease
Air moves along a pressure gradient and enters from a higher atmospheric pressure

Question 4

Advantages of fish having a counter-current principle across the gill in gas exchange

Answer 4

Water and blood flow in opposite directions
Maintains a concentration gradient of oxygen for diffusion along whole of gill