A nonlinear mathematical model for the long-term arterial blood pressure dynamics is derived by integrating the key features of the regulatory mechanisms of cardiovascular-renal systems. In spite of the reduced number of dynamic equations and simplicity of the model, we have incorporated many of the ANA control mechanisms and hormonal activities which operate on different subsystems. The dynamic responses of the physiological model under different types of physiological stresses have been obtained from simulation and have been compared with the data reported in the literature. The results of computer simulations indicate the adequacy of the model as a general dynamic representation of nonlinear cardio-renal system and would be useful for making better cardiovascular diagnosis, prediction and therapy. A sensitivity analysis has also been performed on the model coefficients to test its robustness. The linearized model study has shown that the model is stable under normal conditions.