title: Correlation between shear dependent blood viscosity, electrical resistance and calculated width of the marginal layer in blood perfused capillary tubes.
abstract: Viscosity and shear dependent changes in electrical resistance (delta R) were measured simultaneously in blood perfused capillaries (I.D. = 0.58 mm, 1 = 300 mm, TW = 0.04 to 0.5 Pa). It appears that delta R is primarily caused by the development of a low resistant cell free marginal layer. Red cell aggregation strongly supports the development of delta R, while in non-aggregating blood the shear induced change in conductivity is rather small. Theoretical and experimental data become closely correlated if the calculated width of the marginal layer, being 1 to 5% of the capillary radius, is inserted into a modified form of Poiseuille's law. It is concluded that under the conditions of plug flow the non-Newtonian flow behavior of EDTA blood almost exclusively depends upon the width of the marginal layer, being a function of shear stress and hematocrit.
mesh_terms: D001696:Biomechanical Phenomena; D001790:Blood Physiological Phenomena; D001809:Blood Viscosity; D002196:Capillaries / Q000502:physiology*; D004553:Electric Conductivity; D004903:Erythrocyte Aggregation; D006801:Humans; D008433:Mathematics; D008955:Models, Cardiovascular