Neural regulation of cardiovascular response to exercise: Part II

The changes in circulatory system behavior occurring in response to exercise stress are integrated by the central neural circulatory control system working in cooperation with local regulatory mechanisms. The regulatory events occurring during exercise may be analyzed using a closed-loop regulatory system model of the circulation. In this model, the brain stem acts as the central integration unit determining the set point of the system and the gain of incoming signals from variables such as muscle metabolites and blood gases. Control signals reach the effector organs (heart and peripheral vascular smooth muscle) through sympathetic and parasympathetic motor fibers. Exercise acts on the system as a disturbance, initiating changes in function of effector organs. Local regulatory mechanisms act within the system without passing the central integration unit.