Respiration during Exercise (3)

Question 1

What does Dalton’s law state?

Answer 1

That the total pressure of a gas mixture is equal to the sum of the pressure that each gas would exert independently.

Question 2

What are the partial pressures of O2 and CO2?

Answer 2

O2 - 159mmHg
CO2 - 0.3 mmHg

Question 3

What is the mean pulmonary artery pressure and mean systemic arterial pressure?

Answer 3

o Mean pulmonary artery pressure = 15 mmHg
o Systemic arterial pressure = 100 mmHg

Question 4

Gas exchange requires a matching of ? to ?

Answer 4

Ventilation to blood flow
o The ideal V/Q is 1
o V/Q >1=underperfused (apex of lung)
o V/Q < 1 = overperfused (base of lung)

Question 5

Upon exercise, V/Q improves due to?

Answer 5

o Increased tidal volume
o Increased pulmonary artery pressures
o In some cases, V/Q worsens, especially during heavy exercise

Question 6

What is Henry’s Law?

Answer 6

Amount of O2 dissolved in blood is proportional to partial pressure

• Amount of O2 dissolved is 0.003mL O2/100mL blood/mmHg
• At arterial PO2 of 100mmHg, this results in .003x100=0.3 mL O2/100mL blood

Question 7

What is the arterial O2 content?

Answer 7

20.3 mL O2/100mL blood

Question 8

What is the Bohr effect, and what does it do?

Answer 8

Bohr effect = rightward shift in ODC
- Bohr effect facilitates unloading of O2 to active tissue

Question 9

What does Myoglobin do?

Answer 9

Myoglobin has a high O2 affinity (unloads at very low PO2)
- It shuttles O2 from muscle cell memb to mitochondria for aerobic resp
- Provides intramuscular O2 store

Question 10

What are the 3 ways CO2 is carried in the blood?

Answer 10

1. Dissolved (10%)
2. Bound to haemoglobin (20%)
3. Bicarbonate (70%)

Question 11

Which is more soluble, O2 or CO2?

Answer 11

CO2 is 20x more soluble

Question 12

What is the chloride shift?

Answer 12

Bicarbonate (HCO3) leaves the cell and Cl- moves into the cell to maintain neutrality