Lecture 3: Gas Exchange and Transport Flashcards
what is the respiratory quotient and what is the formula
- metabolic activity of the body in steady state conditions
- Co2 produced / O2 absorbed
what is the respiratory quotient at rest
0.8
what is the respiratory quotient for fat metabolism
0.7
what is the respiratory quotient for carbohydrate metabolism
1.0
what is Fick’s Law
rate of gas transfer is:
- proportional to tissue area
- difference in partial pressure of the gas
- inversely proportional to tissue thickness
what does a low V/Q ratio result in
- decreased arterial pO2
- increased arterial pCO2
what does a high V/Q ratio result in
- increased arterial pO2
- decreased arterial pCO2
what is type 2 respiratory failure
- pure underventilation
- increased PaCO2 and proportionate fall in PaO2
what is type 1 respiratory failure
- disturbance in V/Q matching
- fall in PaO2 with no change to PaCO2
what is the partial pressure of oxygen in the air
21 kPa
what is the alveolar gas equation
PAO2 = PIO2 - (PaCO2/0.8)
what is the normal alveolar arterial gradient in healthy young adults
< 2 kPa