Gas exchange

Question 1

What is Henry’s law?

Answer 1

1. Partial pressure of a gas dissolved in an environment depends on its concentration and the solubility coefficient2. Partial pressure = Conc. dissolved gas / solubility coefficient

Question 2

Is CO2 more or less soluble than oxygen?

Answer 2

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Question 3

What are the results of the high CO2 solubility?

Answer 3

Much less partial pressure exerted, don’t need a large partial pressure difference to transport CO2 across tissue or water in the body

Question 4

What is described by Fick’s law of gas diffusion?

Answer 4

The amount of gas that moves across a sheet is proportional to the area but inversely proportional to thickness

Question 5

What is the equation for net rate of diffusion in fluids?

Answer 5

D = (deltaP x A x S) / (d x sqrtMW) deltaP = partial pressure difference across tissue sheetA = cross sectional area of fluid S = solubility of gas in fluid d = distance through which gas must diffuse MW = molecular weight of gas

Question 6

What is provided, qualitatively, by the alveolar gas equation?

Answer 6

Status of gas exchange, quality of the respiratory membrane, dictates therapeutic decisions