Respiratory System & Lung Ventilation Simulator
Change breathing rate, tidal volume, airway resistance and lung compliance, and watch the lungs and alveoli move air and exchange gas in real time.
Set breathing rate, tidal volume, airway resistance and lung compliance and watch air travel nose → trachea → bronchi → bronchioles → alveoli, with the zoomed alveolus showing real gas exchange.
About the Respiratory System & Lung Ventilation Simulator
Free respiratory system & lung ventilation simulator. Change breathing rate, tidal volume, airway resistance and lung compliance, and watch the lungs and alveoli move air and exchange gas in real time. Drag, change the sliders and see the result live. No sign-up, works on phone and computer. Built for biology, the respiratory system & lung ventilation simulator runs instantly in your browser: change a setting or drag an object and the result updates at once, so you learn by trying things out rather than only reading about them.
Change breathing rate, tidal volume, airway resistance and lung compliance, and watch the lungs and alveoli move air and exchange gas in real time. Use it to explore biology ideas at your own pace, then check what you found against the key ideas further down this page.
How to use the Respiratory System & Lung Ventilation Simulator
- Use the controls to change Breathing rate, Tidal volume, Airway resistance, Lung compliance, Preset. The simulation reacts instantly.
- Pick an option such as Resting, Exercise, Asthma attack to switch modes or load an example.
- Press "Check my breathing", "Check compensation", "Reset to defaults", "📄 Lab Report" to start, reset or change what is happening.
- Where you see a glowing handle, object, weight or atom, drag it with your mouse or finger. Everything responds in real time.
- Watch the readouts and graphs update as you experiment, and compare what you see with the key ideas below.
Things to try
- Load the Exercise preset and watch minute ventilation rise.
- Load the Asthma attack preset and compare the lung-volume trace shape to resting breathing.
- Raise airway resistance alone and see the volume graph change shape even with the same tidal volume.
- Try the challenge: reach a healthy resting minute ventilation between 5 and 8 L/min.
Key ideas you can learn
- Minute ventilation = breathing rate × tidal volume.
- Airway resistance slows the exhale most, stretching the recovery back to resting volume.
- Alveoli exchange oxygen for carbon dioxide by diffusion, driven by the pressure difference across a thin membrane.
- Higher minute ventilation raises alveolar oxygen and lowers alveolar carbon dioxide.
Where this is used in the real world
Doctors read spirometry traces exactly like this one to diagnose asthma, COPD and other breathing conditions, and to track how well treatment is working.
Who is this simulation for?
Biology students and teachers who want to explore living systems, populations and genetics interactively and safely.
For teachers: project it on the board, let students predict what will happen, then run it together. For students: change one thing at a time and write down what changes.
Frequently asked questions
What is tidal volume?
The volume of air moved in or out of the lungs in one normal, quiet breath.
Why does an asthma attack make breathing feel harder?
Narrowed airways raise resistance, which slows airflow (especially breathing out) and can trap air in the lungs.
Is the Respiratory System & Lung Ventilation Simulator free to use?
Yes. It is completely free, with no signup, no download and no ads inside the simulation. It runs in your web browser.
Does the Respiratory System & Lung Ventilation Simulator work on a phone or tablet?
Yes. It uses touch as well as the mouse, so you can drag objects with your finger. A larger screen makes the controls easier to see.