Physiology: Respiratory

Question 1

Alveolar Ventilation

Answer 1

= (VCO2/ PACO2) * K

VCO2- volume of CO2 produced per unit time
PACO2- Alveolar partial pressure of CO2
K- Constant

Question 2

Bohr Equation

Answer 2

VD/VT= PACO2- PECO2/ PACO2

VD/VT- dead space / tidal volume

PACO2- Alveolar partial pressure of CO2 = PaCO2

PECO2- Expired partial pressure of CO2

Question 3

Alveolar Gas Equation (PAO2)

Answer 3

PAO2 = PIO2 - (PACO2/R)

PAO2- partial pressure of alveolar O2
PIO2- partial pressure of inspired O2
PACO2- partial pressure of alveolar CO2
R- Resp. Quotient

Question 4

Respiratory Quotient

Answer 4

= VCO2/ VO2

Question 5

Partial Pressure of Inspired O2

Answer 5

PIO2= FiO2 * (P_atm- P_H20)

P_atm= 101.3kpa

P_H20= 6.3kpa

Question 6

Shunt Equation

Answer 6

Qs/Qt = (Cc_O2-Ca_O2)/ (Cc_O2-Cv_O2)

Qs= Shunted Blood Flow

Qt= Total Blood Flow

Cc_O2= End Capillary Blood O2 Content (assumed to be the same as PAO2)

Ca_O2= Arterial Blood O2 Content

Cv_O2= Mixed Venous Blood O2 Content

Question 7

Compliance

Answer 7

Compliance = V/P

1/C_total= 1/C_lung + 1/C_{chest wall}

Question 8

Blood O2 Content (ml O2/ g Hb)

Answer 8

= (1.39*[Hb]*(S%O2/100))+(0.023*PO2)