# #1 Zhu - Principles of Pulmonary Gas Transport Flashcards

What does Fick’s law measure?

What are the 5 components of Fick’s law?

DIFFUSION RATE Pressure Gradient Area Solubility (Intrinsic property of gas) Distance Molecular Weight FICK = FIVE

Which components of Fick’s law are inversely related to the diffusion rate?

Distance

Molecular Weight

What is the diffusion constant?

Solubility/(sqrt of Molecular Weight)

What does the diffusion capacity determine?

The diffusion capacity determines the ability of the respiratory membrane to transport a gas into and out of the blood.

What are the components of the diffusion capacity?

Area Solubility Distance Molecular Weight It can change due to change in area and/or change in distance.

Where does gas exchange happen?

Respiratory Unit

- Respiratory Bronchioles
- Alveolar Duct
- Alveolar Sac

In emphysema, what would you expect to happen to the diffusion rate and why?

Decreased diffusion rate due to decreased area.

In interstitial edema, what would you expect to happen to the diffusion rate and why?

Decreased diffusion rate due to increased distance.

In fibrosis, what would you expect to happen to the diffusion rate and why?

Decreased diffusion rate due to increased distance.

What is the vapor pressure based on a body temperature of 37 degrees Celsius?

47 mmHg

What is the PO2 of humidified air?

150 mmHg

(760-47) * 0.21

What is the PN2 of humidified air?

563 mmHg

(760-47) *0.79

What is the PO2 of alveolar air?

104 mmHg

What is the PCO2 of alveolar air?

40 mmHg

What is the PO2 in the arterial end of the capillary in the lung?

40 mmHg

What is the PO2 in the venous end of the capillary in the lung?

104 mmHg