Ellsworth M L, Liu A, Dawant B, Popel A S, Pittman R N
Department of Physiology, Medical College of Virginia, Virginia Commonwealth University, Richmond 23298.
Microvasc Res. 1987 Sep;34(2):168-83. doi: 10.1016/0026-2862(87)90051-3.
A quantitative analysis of the distribution of microvascular blood flow and oxygen delivery requires a detailed description of the vascular network geometry. The distributions of lengths and diameters were determined in terminal arteriolar networks of the cheek pouch retractor muscle of young (34 +/- 2 days) hamsters. We compared the Strahler centripetal vessel ordering scheme, which assigns lowest order to the capillaries and proceeds upstream toward the larger vessels, with the centrifugal ordering scheme, which begins with the input arteriole and proceeds downstream toward the capillaries. The terminal networks of the retractor muscle typically contain 2 to 4 Strahler orders and 2 to 6 centrifugal orders. The coefficients of variation of diameter and length are smaller for Strahler ordering than for centrifugal ordering. In addition, for Strahler ordering, we found that the sequence of number of vessels obeyed Horton's law. We have compared three different methods of calculating the bifurcation, diameter, and length ratios. As an alternative method for analyzing network topology, we also studied the distribution of the number of segments on each pathway from the inlet of a network to a capillary. The information obtained from this analysis is useful for the mathematical modeling of flow in the microvascular network.
对微血管血流分布和氧气输送进行定量分析需要对血管网络几何结构进行详细描述。在年轻（34±2天）仓鼠颊囊牵张肌的终末小动脉网络中确定了长度和直径的分布。我们将向心血管分级方案（该方案将最低级别赋予毛细血管，并向上游朝向较大血管推进）与离心分级方案（该方案从输入小动脉开始，并向下游朝向毛细血管推进）进行了比较。牵张肌的终末网络通常包含2至4个斯特拉勒级别和2至6个离心级别。斯特拉勒分级的直径和长度变异系数比离心分级的小。此外，对于斯特拉勒分级，我们发现血管数量序列符合霍顿定律。我们比较了三种计算分支、直径和长度比的不同方法。作为分析网络拓扑的替代方法，我们还研究了从网络入口到毛细血管的每条路径上节段数量的分布。从该分析中获得的信息对于微血管网络中血流的数学建模很有用。
