Measurements of carbon dioxide diffusivity and thermal conductivity in muscle tissue

The values of effective diffusivity for carbon dioxide and thermal conductivity have been measured in freshly excised respiring rat abdominal muscle in order to understand the heat and mass transport process occurring in the muscle tissue. The values of diffusivity increase with the decrease of the average partial pressure of CO₂, indicating the existence of significant facilitated diffusion. The thermal conductivity of the muscle tissue membrane in which the paritial pressure gradient of carbon dioxide was imposed was measured by the self-heated thermistor method. There appears to be a slight increase of diffusivity at the lower partial pressure and this finding indicates that there may exist some mechanism of simultaneous heat and mass transport in the muscle tissue.