Gas Exchange (4)

Question 1

How do ideal gas law apply to respiratory gas exchange?

Answer 1

Ideal gases do NOT condense, evaporate, or sublime at operating range

• O2 and CO2 are Ideal cases at operating ranges
• Ideal gases follow PV=nRT formula
• since temp. between the inspired air and the body are similar due to warming and humidification, PO2 + VO2 = PCO2 +VCO2
• Since there is a partial pressure difference, diffusion occurs both ways until equilibrium

Question 2

how does ATELECTASIS affect gas exchange

Answer 2

• Change in pressure is DECREASED (alveolar PO2 is decreased), resulting in decreased diffusion

Question 3

How does PULMONARY FIBROSIS affect gas exchange

Answer 3

distance of diffusion increases (interstitial thickness), resulting in decreased diffusion

Question 4

How does PULMONARY EDEMA affect gas exchange

Answer 4

Distance of diffusion increases (fluid in interstitium), resulting in decreased diffusion

Question 5

How does PNEUMONIA affect gas exchange

Answer 5

Distance of diffusion increases (inflammation of alveoli), resulting in decreased diffusion

Question 6

define the relationship between diffusion and perfusion in the effectiveness of gas exchange in lungs

Answer 6

Both proper ventilation and perfusion are necessary to establish the appropriate partial pressure difference for diffusion to occur properly

Question 7

Describe the process of O2 exchange at alveoli-pulmonary capillaries under normal conditions and during strenuous exercise

Answer 7

NORMAL: blood passes through capillaries, blood PO2 is almost fully saturated after traveling 1/3 distance of capillary.
EXERCISE: 20x the amount of O2 can be needed, CO increases, which reduces the amount of time the blood spends in capillaries
- diffusion capacity increases in excercise, so blood is almost saturated before leaving capillary