Equations Flashcards
Henry’s Law: definition
The concentration of gas in a solution is directly proportional to its solubility and partial pressure
Henry’s Law: equation
C = alpha(P)
Fick’s Law: definition
Diffusion of a gas is directly proportional to surface area and partial pressure
Diffusion is inversely proportional to thickness
Fick’s Law: equation
Diffusion = A/x(D)(deltaP)
F (flow) =
P/R
IC
Vt + IRV
EC
Vt + ERV
FRC
RV + ERV
VC
IC + ERV
(Vt + IRV + ERV)
TLC
VC + RV
(Vt + IRV + ERV + RV)
Vm
Vm = Vt * RR
VA
VA = (Vt - Vds) * RR
Vds
Vds = 150 * RR
Px
Px = Total pressure of mixture * %x in mixture
Alveolar ventilation equation
PACO2 = VCO2/VA
(VCO2 = volume of CO2)
Alveolar gas equation
PAO2 = PIO2 - PACO2/R
(R = CO2 produced/O2 consumed)
PTP
PTP = Palv - PIP
PTR
PTR = Palv - Patm
Compliance =
V/P
Flow =
P/R
Law of LaPlace
P = 2T/r
(T = surface tension; r = radius)
R (resistance) =
8nl/πr4
(n = viscosity, l = length of segment, r = radius)
RQ (respiratory quotient) =
CO2 produced/O2 consumed
Px =
Px = Ptotal*Fx
PIO2 =
(Patm - Pvapor) * 0.21
Fick’s Law
Gas flow = A/x*D*(P1-P2)
Alveolar ventilation equation
PACO2 =
VCO2/Valv
(VCO2 = CO2 production; Valv = alveolar ventilation)
Alveolar gas equation
PAO2 =
PAO2 = PIO2 - PACO2/R
H-H
pH = pKa + log[HCO3-]/[CO2]
pH = 6.1 + log[HCO3-]/0.03PCO2
PBF =
(Ppulmartery - PLV)/R
