International A Level Biology / Membranes and transport
How the lung is adapted for gas exchange
Edexcel International A Level Biology (YBI11), chapter 4: Membranes and transport, specification point 2.1. Part of the full course.
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The lungs are adapted so oxygen diffuses quickly from the air in the alveoli into the blood. Each adaptation affects a part of Fick’s law, which links diffusion rate to surface area, concentration difference and thickness.