Rheology of the microcirculation.
Rheology of the microcirculation.
复制标题
DOI：
--
复制
发表时间：
2003
影响因子：
2.1
通讯作者：
Axel R. Pries;T. Secomb
中科院分区：
文献类型：
--
作者：
Axel R. Pries;T. Secomb
微血管系统的主要功能是控制与周围组织的物质交换。这就需要一个大的容器表面，由大量的小直径容器组成，因此固有的高个体流动阻力。具有给定血管结构的微血管网络的水动力阻力取决于微血管中流动的血液的表观粘度。表观粘度随着直径的减小而下降（Fahraeus-Lindqvist效应），并且在直径约为5-7微米时最小，这是由于红细胞与流体的最佳对齐。在体内，许多其他现象影响血液流变学和网络血流动力学。血流和红细胞通量在网络内的分布受到红细胞在个别分叉处运动的机制（相分离效应）的影响。此外，最近的研究表明，在微血管的管腔表面存在一层厚的内皮表面层（约0.5微米），它与内皮糖萼相连。这一层调节流动阻力，并可能与许多其他过程有关，如炎症反应和血液凝固。微血管流变学信息可用于建立网络血流动力学和血管适应局部环境（血管适应）的数学模型，以研究建立和维持功能充足的微血管网络的复杂相互关联的机制。
The main function of the microvasculature is the controlled exchange of materials with surrounding tissues. This necessitates a large vessel surface established by a high number of vessels with small diameters and thus an inherently high individual resistance to flow. The hydrodynamic resistance of a microvascular network with given angioarchitecture depends on the apparent viscosity of blood flowing in the microvessels. Apparent viscosity declines with decreasing diameter (the Fahraeus-Lindqvist effect) and is minimal at diameters of about 5-7 micrometers due to the optimal alignment of red cells with the flow. In vivo, a number of additional phenomena influence blood rheology and network hemodynamics. The distribution of blood flow and red cell flux within networks is influenced by the mechanics of red cell motion at individual diverging bifurcations (phase-separation effect). Furthermore, recent studies have revealed the presence of a thick endothelial surface layer ( approximately 0.5 micrometers) on the luminal surface of microvessels which is attached to the endothelial glycocalyx. This layer modulates flow resistance and may be relevant for a number of other processes such as inflammatory responses and blood coagulation. Information on microvascular rheology can be used to develop mathematical models of network hemodynamics and vascular adaptation to the local environment (angioadaptation), to investigate the complex interrelated mechanisms which establish and maintain functionally adequate microvascular networks.