Gas exchange and respiration

Question 1

What causes o2 and co2 partial pressure change in the alveolus?

Answer 1

1. Alveolar ventilation rate (runs to asymptote)
2. Increase o2 consumption + co2 produced (exercise)
3. Altitude

Question 2

How does altitude effect partial pressures?

Answer 2

Low atmospheric pressure = increase in BF to get more blood to the brain.
Partial pressure of o2 decreases

Question 3

Which is more soluble Co2 or o2 ?

Answer 3

Co2

Question 4

Describe the partial pressure of o2 in pulmonary arteries and venules

Answer 4

Arteries (deoxy) = 40

Veins (oxy) = 104

Question 5

Describe the partial pressure of Co2 in arteries and venules

Answer 5

Arteries = 45
Viens = 40

Question 6

What happens in hypoxic vasoconstriction ?

Answer 6

po2 within alveoli decreases = decreased BF in THAT alveoli
less o2 = K+ channels close = cells depolarise and contract
This is in pulmonary circulation… different for in systemic

Question 7

How is Co2 most commonly transported ?

Answer 7

HCO3

Question 8

What does lower plasma pH do?

Answer 8

Indirectly increases the resp rate to drive off co2

Lower Ph shifts the saturation to the right (Bohr effect)