Hydrodynamic modelling of stress

This work is a qualitative study of an organism's physiological adaptative response to stress. The experimental data were selected from a previous stu dy leading to the conclusion that stress may be considered as a topological retraction within a vital space that must be more precisely defined. The e xperimental methodology uses rat poisoning by neurotoxins. The control para meter is the intensity of the toxic doses. Measured parameters are the anim als' survival rate and the kinetics of cerebral acetylcholinesterase activi ty. The results, when expressed as a function of the inverted doses, show a characteristic evolution. The pattern of the curve closely resembles a vor tex profile. This analogy is studied more extensively in both the physical and biological domains. These findings help to clarify the concept of biolo gical stress which presents the same vectorial properties as hydrodynamic v orticity. In particular, the dissipation of stress and the dissipation of v orticity seem to obey the same laws. This observation is valid for both dif fusion and convection processes. The decompensation phase of stress could b e compared with the instability and turbulence in flows. Our approach in this paper is mainly to establish a general and phenomenolo gical description of the stress response fitting experimental observations.