Exchanging Materials In Mammals Flashcards
1
Q
How does had exchange happen?
A
The job of the lungs is to transfer oxygen to the blood and to remove waste carbon dioxide from it. To do this the lungs contain millions of little air sacs called alveoli where gas exchange takes place. The alveoli are specialised to maximise the diffusion of oxygen and co2.
2
Q
How are the alveoli specialised?
A
- they have an enormous surface area
- a moist lining for dissolving gases
- very thin walls
- a good blood supply
3
Q
Villi. What? How?
A
The inside of the small intestine is covered in millions and millions of villi. They increase the surface area in a big way so that digested food is absorbed much more quickly into the blood. They have •a single layer of surface cells. •a very good blood supply to assist quick absorption
4
Q
Where does gas exchange happen?
A
In the lungs
