Measurements of Oxygen Transport in Single Capillaries
Most oxygen is tranported to tissue cells across the walls of capillaries. The thin barrier between blood and the interstitial space and the relatively long contact time of blood within the capillary make diffusional oxygen exchange an effective process. Since most oxygen is carried in reversible combination with. hemoglobin inside the red cells (RBC), erythrocytes play a dominant role in any description of oxygen transport at the capillary level. The rate at which oxygen is delivered to a capillary is equal to the number of red cells entering the capillary per unit time (RBC flux) times the oxygen content per red cell. The amount of oxygen removed from an RBC as it traverses a capillary depends upon the radial gradient in oxygen partial pressure (PO2), the RBC flux and length of the capillary. The radial gradient in PO2 at the capillary wall is determined by tissue oxygen consumption, diffusion coefficient and solubility. In addition, the neighboring capillaries can influence the PO2 distribution in tissue.
KeywordsOxygen Delivery Oxygen Transport Video Analyzer Linear Regression Line Capillary Length
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