Respiratory 20

Question 1

Which portion of air has variable partial pressure?

Answer 1

Water

Question 2

Where does the partial pressure of water in the air increase?

Answer 2

In the alveoli after it has been warmed

Question 3

How are the partial pressures of oxygen and carbon dioxide affected from the air to the alveoli?

Answer 3

• The partial pressure oxygen from air to the alveoli is reduced
• The partial pressure of carbon is dramatically increased from the air to the alveoli

Question 4

What happens as soon as air enters the alveoli?

Answer 4

Oxygen moves from the alveoli into the lung capillaries

Question 5

Why is the pressure of O2 in the air greater than the pressure of O2 in the alveoli?

Answer 5

• The partial pressure of water increases when air is warmed up causing the partial pressure of O2 to decrease
• Much of the O2 goes into the blood immediately through diffusion
• Inspired air mixes with the the functional residual volume

Question 6

What are the determinants of alveolar PO2?

Answer 6

• PO2 in the atmosphere
• Alveolar ventilation
• Metabolic rate
• Perfusion

Question 7

What are the Determinants of Alveolar PCO2?

Answer 7

• PCO2 in the atmosphere
• Alveolar ventilation
• Metabolic rate
• Perfusion

Question 8

How does ventilation affect PO2?

Answer 8

Increased ventilation will cause the air in the alveoli to be more similar to the air in the atmosphere

Question 9

How does Metabolic rate influence PO2?

Answer 9

Increased metabolic rate will cause returning venous blood to have lower levels of O2 so the PO2 levels will be decreased

Question 10

What is the difference between P alveolar CO2 and P atmospheric CO2?

Answer 10

P alveolar CO2 is much higher that P atmospheric CO2

Question 11

How does decreased ventilation affect PCO2?

Answer 11

A decrease in alveolar ventilation causes less exhalation of CO2 from the alveoli and PCO2 will be increased in the alveoli

Question 12

How does increased metabolic rate affect PCO2?

Answer 12

Increased metabolic rate causes more CO2 to diffuse back into the alveoli increasing PCO2

Question 13

How does increasing alveolar ventilation affect PO2 and PCO2?

Answer 13

Increasing alveolar ventilation will increase PO2 and decreased PCO2

Question 14

How does decreasing alveolar ventilation affect PO2 and PCO2?

Answer 14

PCO2 will increase and PO2 will decrease

Question 15

How does increasing metabolic rate affect PO2 and PCO2?

Answer 15

PO2 will be decreased and PCO2 will be increase

Question 16

How does decreasing metabolic rate affect PO2 and PCO2?

Answer 16

PCO2 will decrease and PO2 will increase