Human Phys 6.6 Flashcards
What percentage of dissolved O2 accounts for total O2 content in the blood?
2%
What form of O2 produces a partial pressure?
Dissolved gas
What drive diffusion?
Partial pressure
What is O2 bound to?
Hemoglobin
What percentage does bound gas account for?
98%
Does bound gas contribute to partial pressure?
No
What does CO2 get modified into?
HCO3 by carbonic anhydrase
What is perfusion limited gas exchange limited by?
Amount of blood
What is diffusion limited gas exchange limited by?
Strenuous exercise
Emphysema and fibrosis
What is the only way to get more diffusion?
Get more blood flow
What does pulmonary blood flow determine?
O2 transfer
What do both O2 and CO2 bind to for transport?
Hemoglobin
Why does O2 reach diffusion equilibrium while CO2 does not?
Hemoglobin in mixed venous blood is already about 75% saturated with O2
When does blood become almost fully saturated with oxygen?
By the time it passed through 1/3 of the pulmonary capillary and little additional oxygen normally enters the blood during the later 2/3
How long does the blood stay in the lung capillaries to cause full oxygenation?
3x as long