diff --git a/docs/figures/mole-bridge.svg b/docs/figures/mole-bridge.svg new file mode 100644 index 0000000..36296e8 --- /dev/null +++ b/docs/figures/mole-bridge.svg @@ -0,0 +1,34 @@ + + + + + + + One atom + carbon-12 + 12 amu + + + One mole + 6.022 × 10²³ + particles + Avogadro's number + + + On the balance + carbon + 12 g + + + + + 1 amu is 1/12th of a carbon-12 atom — which is what makes the two ends of this line agree. + Equal volumes of gases, at the same temperature and pressure, hold equal numbers of particles. + diff --git a/docs/figures/parabolic-profile.svg b/docs/figures/parabolic-profile.svg new file mode 100644 index 0000000..b4efa28 --- /dev/null +++ b/docs/figures/parabolic-profile.svg @@ -0,0 +1,40 @@ + + + + + + + + + + + + + + + + + + + + + + + + + fresh gas · centre lane · fastest + spent gas · wall layer · dwells longest + spent gas · wall layer · dwells longest + + v(r) = v_max (1 − r²/R²) + No-slip at the wall: the layer touching it does not move at all. + Oscillate this and the two lanes travel in opposite directions — Taylor dispersion. + diff --git a/docs/figures/respiratory-failure-types.svg b/docs/figures/respiratory-failure-types.svg new file mode 100644 index 0000000..95672b2 --- /dev/null +++ b/docs/figures/respiratory-failure-types.svg @@ -0,0 +1,41 @@ + + + + + + Type 1 · lung failure + PaO₂ ↓ · PaCO₂ normal or low + V/Q mismatch, shunt, diffusion defect. + Bronchiolitis, pneumonia, PARDS, oedema. + True shunt needs PEEP, not more FiO₂. + + + Type 2 · pump failure + PaCO₂ > 50 with pH < 7.30 + Alveolar hypoventilation. + CNS depression, neuromuscular, exhaustion + at the end of severe obstruction. + + + Type 3 · perioperative + FRC falls + Anaesthesia, positioning, opiates, splinting. + Basilar collapse, then V/Q mismatch. + + + Type 4 · shock + The diaphragm competes for cardiac output + Respiratory muscles take up to 40% of it. + Ventilation offloads them, for the organs. + + Distress is compensated; failure is not. A "normal" PaCO₂ in an exhausted tachypnoeic child is a rising one. + diff --git a/docs/figures/salter-harris.svg b/docs/figures/salter-harris.svg new file mode 100644 index 0000000..e80a09f --- /dev/null +++ b/docs/figures/salter-harris.svg @@ -0,0 +1,65 @@ + + + + + + + + + + + + + + + + Type I + through the physis + + + + + + + Type II + + metaphyseal corner + + + + + + + Type III + into the joint + + + + + + + Type IV + across all three + + + + + + + + + + + Type V + crush + + + Amber: the physis. Red: the fracture line. + diff --git a/docs/figures/two-zone-lung.svg b/docs/figures/two-zone-lung.svg new file mode 100644 index 0000000..1cb32d2 --- /dev/null +++ b/docs/figures/two-zone-lung.svg @@ -0,0 +1,37 @@ + + + + + + + + + + + + + + + + + + + + Conducting zone + Trachea → terminal bronchioles, ~16 generations + Convection: bulk flow and streaming. + No exchange at all — this is plumbing. + + Respiratory zone + Diffusion; flow velocity ≈ 0. + O₂ and CO₂ cross the membrane here. + + Flow only has to reach the doorstep: across one alveolus, t ≈ x²/D ≈ 2.5 ms. +