Figure 6.

Schematic of contributions to distribution of blood. (A) Vascular asymmetry contributes to heterogeneity, and decrease in perfusion in the extremities; (B) hydrostatic pressure gradient acts directly on blood to drive it preferentially downwards, and introduces a constraint at the capillary level; (C) deformation of tissue establishes a gravitational gradient of vessels per unit tissue, enhancing the flow gradient; also contributes to reduction in flow in most dependent region; (D) combined result is a gravitational gradient and isogravitational heterogeneity, each affected by multiple mechanisms.