Arterial branching in various parts of the cardiovascular system.

Angiographic pictures of vascular beds in various parts of the cardiovascular system were analyzed to study the geometrical structure of arterial bifurcations. The sites of arterial bifurcations were enlarged individually, and measurements were made of the branching angles and branch diameters at each site. Results from various parts of the cardiovascular system of man, and some from rabbit and pig, were compared with each other. The measurements were also compared with "optimum" values of branching angles and branch diameters which have been predicted by various theoretical studies. In general the measurements were found to give support to the theoretical premise that branching angles and branch diameters in the cardiovascular system are dictated by certain optimality principles which aim to maximize the efficiency of the system in its fluid-conducting function. In some parts of the system, however, the measured angles and diameters were found to be decidedly lower than those predicted by theory.