Gas exchange Pulmonary gas exchange Tissue gas exchange Tissue cells CO CO CO CO Pulmonary capillary Tissue capillaries
Gas exchange Tissue capillaries Tissue cells CO2 O2 CO2 O2 Pulmonary capillary CO2 CO2 O2 O2 Pulmonary gas exchange Tissue gas exchange
Physical principles of gas exchange Diffusion continuous random motion of gas molecules ■ Partial pressure:the individual pressure of -..o each gas, eg. PO ada
Physical principles of gas exchange ◼ Diffusion: continuous random motion of gas molecules. ◼ Partial pressure: the individual pressure of each gas, eg. PO2
P1V1=P2v2 Compression Decompression ↓v→↑P tv→4P Boyle's law states that the pressure of a fixed number of gas molecules is inversely proportional to the volume of the container
Boyle’s law states that the pressure of a fixed number of gas molecules is inversely proportional to the volume of the container
Laws governing gas diffusion P2 ■ Henry's law: The amount of dissolved gas is directl ty proportional to the partial pressure of the gas 88EEa 0100200300400500600700 Pao2(mmHg)
Laws governing gas diffusion ◼ Henry’s law: The amount of dissolved gas is directly proportional to the partial pressure of the gas
Laws governing gas diffusion ■ Grahan'sLaW When gases are dissolved in liquids, the relative rate of diffusion of a given gas is proportional to its solubility in the liquid and inversely proportional to the square root of its molecular mass diffusion rate of COz: 2232=19 diffusion rate of 02 44
Laws governing gas diffusion ◼ Graham's Law When gases are dissolved in liquids, the relative rate of diffusion of a given gas is proportional to its solubility in the liquid and inversely proportional to the square root of its molecular mass