Module 3 Equations

Question 1

Flow Equation

Answer 1

△ Pressure / Resistance = Flow (V)

Question 2

Law of LaPlace

Answer 2

2T (surface tension) / r (alveolar radius) = P (collapsing pressure)

Question 3

Alveolar Pressure

Answer 3

Alveolar Pressure (PA) – Pleural Pressure (PPl) = Lung Recoil Pressure (Pl)

Question 4

Poiseuille’s Law

Answer 4

Flow rate (Q) = π△Pr^4 / 8ηL

Question 5

Minute Ventilation Equation

Answer 5

Tidal Volume (VT) x Respiratory Frequency (f) = Minute Ventilation (V̇E)

Question 6

Gas Diffusion

Answer 6

VˇCO2 = (PAˇCO2 - PVˇCO2) * A/T

VˇO2 = (PAˇO2 - PVˇO2) * A/T

Question 7

Alveolar Gas Equation

Answer 7

PIˇO2 – PAˇCO2/R = PAˇO2