Abstract
The arterial baroreflex system is an important negative feedback system to regulate arterial pressure (AP). This system may be analyzed by dividing it into a controller subsystem (the neural arc) and a plant subsystem (the peripheral arc). The former determines SNA in response to baroreceptor input pressure, and the latter determines AP in response to SNA. We have employed a framework of an open-loop analysis to identify the neural and peripheral arc characteristics. With respect to dynamic characteristics, the neural arc shows derivative characteristics whereas the peripheral arc shows low-pass characteristics. The fast neural arc compensates for the slow peripheral arc to accelerate the total reflex arc. With respect to static characteristics, the neural arc has inverse-sigmoidal relation between input pressure and SNA whereas the peripheral arc has more linear relation between SNA and AP. A baroreflex equilibrium diagram can be obtained by plotting the two arcs on a pressure-SNA plane. By using the baroreflex equilibrium diagram, we can schematically understand how changes in the neural arc, peripheral arc, or both of them, affect the operating point of the arterial baroreflex.
