Alveolus gas exchange sim
Turn the knobs on an alveolus teaching model to change breathing, blood flow, wall thickness and altitude, watch oxygen and carbon dioxide cross one alveolus and its capillary, take your own readings and graph them.
Breathing and gas exchange · covers the O-Level, IGCSE, GCSE topic
What the sim shows
Model: oxygen and carbon dioxide diffuse across a wall about 0.5 µm thick, each down its concentration gradient; breathing and blood flow keep the gradients steep. At rest the alveolar air holds 13.3 kPa of oxygen and 5.3 kPa of carbon dioxide; blood arrives at 5.3 and 6.1 kPa and leaves at 13.3 and 5.3 kPa, taking up 219 mL of oxygen a minute. Values illustrative, from memory; partial pressures and Fick's law are beyond the syllabus.
- Centre alveolus of the teaching model: one air sac, covered in capillaries
- Arteriole dark red (blood in), venule bright red (blood out)
Use it in your lessons
- Try it here: anyone can unlock 2 figures free, and a free account unlocks up to 5. Runs on a laptop, a Chromebook or a phone; nothing to install.
- Present it and share student links with the teacher plan, from US$5 a month, billed yearly.
- Put it on your own website or LMS for US$9, paid once, or every sim from US$29 a month.
Free guide: 12 practicals as sims, and how to run one in a lesson →
Need a version for your exact set-up? Have one made: US$49 a figure in an order of 5.
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