Opti / Respiratory mechanics
5 lessons

Breathing, from first principles.

Short lessons with experiments you can explore. Read the idea, make a prediction, then use the 3D model to see what happens. Each lesson builds on the one before it.

  1. Boyle's lawChange the volume, change the pressure. Boyle's law with a piston you can drag.
  2. Pressure gradientsGas moves down a gradient. Set two pressures, open the valve, watch them meet.
  3. From volume to flowChange a volume that is open to the room and a gradient appears on its own. Volume, pressure, and airflow together.
  4. The pleural spaceHow the body pulls the piston. A lung in a jar, a diaphragm for a floor, and the four pressures of breathing.
  5. ComplianceHow much volume a pressure buys. Three lungs, one effort, and the pressure-volume curve.
  6. ResistanceHow much flow a gradient buys you, and why time constants matter. · Coming soon

Pressures are in cmH₂O relative to atmosphere unless a screen says otherwise. Volumes are litres. Molecule counts are exaggerated so small pressure differences are visible.