Relations between heat transfer in perfused biological tissue and the local symmetry components of the vascular system.

The relation between perfusion and heat transfer in tissue can be formulated in terms of local symmetry components of the vascular system. It is shown that the order of symmetry (dipole, quadrupole etc. symmetry) gives the order of magnitude of perfusion heat transfer. A unidirectional flow component results in a D'Arcy like bulk flow. A non unidirectional flow component contributes to heat transfer at least by a second order term. It acts like an additional effective heat diffusivity. Comparison with experiments confirm the theoretical results.