Biology 7

Describe and explain how the lungs are adapted to allow rapid exchange of oxygen

between air in the alveoli and blood in the capillaries around them.

Many alveoli / alveoli walls folded provide a large

surface area;

2 Many capillaries provide a large surface area;

3 (So) fast diffusion;

Alveoli or capillary walls / epithelium / lining are thin /

short distance between alveoli and blood;

5 Flattened / squamous epithelium;

6 (So) short diffusion distance / pathway;

7 (So) fast diffusion;

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8 Ventilation / circulation;

9 Maintains a diffusion / concentration gradient;

10 (So) fast diffusion;