Network analysis of microcirculation of cat mesentery

The modular configuration of the microcirculatory system in cat mesentery is subjected to a hydrodynamic network analysis assuming Poiseuillian dynamical behavior. Intravascular pressure, vessel pressure gradient, and wall shear stress are computed for an isolated module and presented as a function of vessel diameter, from arterial affluent to venous effluent. Computed and in vivo intravascular pressures show a marked disparity on the arterial side of the true capillaries and a fair agreement on the venous side. This is attributed to the effects of precapillary sphincter action and non-Newtonian rheological behavior. Computed pressure gradients based on a simple Poiseuillian relationship are approximately six times greater than those measured in vivo. By comparison of predicted and measured pressure gradients, the magnitude of maximum vessel wall shear stress is estimated to be on the order of 10 dyn/cm².