3.2.8

Alveoli

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Alveoli

The alveoli are tiny air sacs in the lungs. Oxygen and carbon dioxide move between the air and blood by diffusion in the alveoli. Alveoli are adapted to be very efficient at exchanging substances:

Illustrative background for Large surface areaIllustrative background for Large surface area ?? "content

Large surface area

  • Alveoli have a large surface area.
Illustrative background for Surrounded by capillariesIllustrative background for Surrounded by capillaries ?? "content

Surrounded by capillaries

  • Alveoli are surrounded by a network of capillaries and so:
    • they have a rich oxygen supply.
    • the distance for gases to diffuse is small.

Jump to other topics

1The Nature & Variety of Living Organisms

2Structure & Functions in Living Organisms

3Organism Functions

3.1Respiration

3.2Gas Exchange

3.3Transport

3.4Excretion

3.5Coordination & Response

4Reproduction & Inheritance

5Ecology

6Biological Resources

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