Flow Equation
△ Pressure / Resistance = Flow (V)
Law of LaPlace
2T (surface tension) / r (alveolar radius) = P (collapsing pressure)
Alveolar Pressure
Alveolar Pressure (PA) – Pleural Pressure (PPl) = Lung Recoil Pressure (Pl)
Poiseuille’s Law
Flow rate (Q) = π△Pr^4 / 8ηL
Minute Ventilation Equation
Tidal Volume (VT) x Respiratory Frequency (f) = Minute Ventilation (V̇E)
Gas Diffusion
VˇCO2 = (PAˇCO2 - PVˇCO2) * A/T
VˇO2 = (PAˇO2 - PVˇO2) * A/T
Alveolar Gas Equation
PIˇO2 – PAˇCO2/R = PAˇO2