Study On The Chaotic Behavior Of The Nonlinear Dynamical Model For Human Interal Secretion

Proposing the nonlinear dynamical model and researching the property of hormone pulsatile secretion in human body can help us to find out the interaction of hormones and the binding of cortisol with proteins in plasma and tissues in the internal secretion feedback system. The theoretical results of the optimized model may help and promote the applied research of medical treatment engineering.In this thesis the nonlinear dynamical model for the Hypothalamo-pituitary-thyroid axis hormone secretion is revised and analyzized with Maplesoft simulated system. The equation group of the model is solved by the variable-stepsize fourth-order Runge-Kutta method. And the periodic oscillate solutions, chaos solutions and corresponding phase space diragrams are presented. The basal concentration, production rate, metabolic cleanance rate and half-life time of hormone are calculated. It is shown that the analysis agrees well with the experimental results and also gives a reasonable explanation to the periodic and chaotic phonomenon of human internal secretion.