Secomb T W, Hsu R
Department of Physiology, University of Arizona, Tucson 85724, USA.
J Biomech Eng. 1996 Nov;118(4):538-44. doi: 10.1115/1.2796041.
Red blood cells undergo continual deformation when traversing microvessels in living tissues. This may contribute to higher resistance to blood flow observed in living microvessels, compared with that in corresponding uniform glass tubes. We use a theoretical model to simulate single-file motion of red cells though capillaries with variable cross-sections, assuming axisymmetric geometry. Effects of cell membrane shear viscosity and elasticity are included, but bending resistance is neglected. Lubrication theory is used to describe the flow of surrounding plasma. When a red cell encounters a region of capillary narrowing, additional energy is dissipated, due to membrane viscosity, and due to narrowing of the lubrication layer, increasing the flow resistance. Predicted resistance to cell motion in a vessel with periodic constrictions (diameter varying between 5 microns and 4 microns) is roughly twice that in a uniform vessel with diameter 4.5 microns. Effects of transient red cell deformations may contribute significantly to blood flow resistance in living microvessels.
红细胞在穿过活组织中的微血管时会不断变形。与相应的均匀玻璃管相比，这可能是导致在活的微血管中观察到的血流阻力更高的原因之一。我们使用一个理论模型来模拟红细胞在具有可变横截面的毛细血管中的单列运动，假设为轴对称几何形状。该模型考虑了细胞膜的剪切粘度和弹性，但忽略了弯曲阻力。润滑理论用于描述周围血浆的流动。当红细胞遇到毛细血管变窄的区域时，由于膜粘度以及润滑层变窄，会消耗额外的能量，从而增加流动阻力。预测在直径在5微米和4微米之间周期性收缩的血管中细胞运动的阻力大约是直径为4.5微米的均匀血管中的两倍。红细胞瞬时变形的影响可能对活的微血管中的血流阻力有显著贡献。
