Figure 2.

Cardiovascular model to describe the change in mean arterial BP after administration of different compounds acting on CO and TPR. MAP equals the product of CO and TPR (MAP = CO × TPR). Effects on CO and TPR are described by two linked turnover equations. In these equations K_in__CO and K_in__TPR represent the zero-order production rate constants of CO and TPR; and k_{out_CO} and k_out__TPR represent the first-order dissipation rate constants of CO and TPR. When MAP increases as a result of a stimulating effect on CO or TPR, the values of CO and TPR will decrease as a result of the action of the different feedback mechanisms regulating the CVS. In this model, the magnitude of feedback on CO and TPR is represented by FB1 and FB2.