THE PHYSIOLOGICAL PRINCIPLE OF MINIMUM WORK APPLIED TO THE ANGLE OF BRANCHING OF ARTERIES

which embodies Poiseuille's law of flow and a term which covers the cost of maintenance of blood volume, p is the fall in pressure in dynes/cm. ~, b is the cost of blood volume in ergs/cc, sec. (considered constant), vol is the volume, r is the radius of the section of artery, and 71 is the viscosity of whole blood (also taken as "constant"). At constant flow, f (that is, for any given steady state), and at constant length of arterial section, l, the total energy, E, is a minimum when: