Pattern of vascular resistance contributes to blood flow heterogeneity
The blood flow patterns in vascular networks becomes heterogeneous when the resistances of sister vessels become unequal. We determined in theory effects on flow heterogeneity for two types of resistance inequalities: (1) left-hand sisters drawn randomly from one pair of distributions of vessel length and radius, A, and right-hand sisters drawn from a different pair of distributions, B; and (2) sisters in the upper network half drawn from pair A and those in the lower half drawn from pair. B (Fig 1). To facilitate comparison, the same lengths and radii used to make type (1) vessels were used to make type (2). Blood flow in type (2) was bimodal and lognormally distributed. Type (1) flow was lognorrnal and uni- or multimodal (Fig 2). We conclude that flow heterogeneity is governed by both vessel location and vessel size. (Supported by the South Carolina chapter of American Heart Association.).