Effect of a Branching Capillary Network on the Differential Flow Velocities of Plasma and Corpuscles

Abstract

MEASUREMENT of the relative velocities of corpuscles and plasma by timing the travel of traceable materials between different points in the living body^1,2 shows that the mean transit time of the cells is appreciably less than that of the plasma and this is generally attributed to the effect of axial drift of the red cells in the minute vessels. Groom, Morris and Rowlands³ showed that the whole of the cell arrival curve was displaced in time ahead of the plasma arrival curve. Thus some of the red cells apparently advanced bodily ahead of the plasma with which they were injected. Whitmore⁴ compared these results with those of a theoretical hydrodynamic model, which he developed, and concluded that axial accumulation of cells in streamline flow should only affect the shape of the later portion of the cell-concentration curve; the initial rise of both curves should occur at the same moment and at a comparable rate. Thus such a model did not account for the observed time displacement of the whole cell curve ahead of the plasma curve and the advancement of the leading cells ahead of the plasma with which they were injected.