[Oscillations in the cardiovascular system--physical models for the interpretation of physiological phenomena]

We discuss the foundations of the theory of homeostasis within the framework of modern physics. We analyse the paradigm of homeostasis, which is based on the physical assumption that the internal environment undergoes random fluctuations around a steady state equilibrium. We show how the notion of homeodynamics extends the concept of homeostasis. We introduce the paradigm of the phase sensitivity of regulatory activity which supplements the classical paradigm of the tonic character of such activity.