Nonlinear analysis of the baroreceptor reflex system.

• The cardiovascular system is a complex mechanical, chemical, and hemodynamic system in which the variables are interrelated through a variety of feedback mechanisms. Of the various mechanisms that control cardiovascular function, the one that has been most thoroughly investigated is the baroreceptor reflex. The performance of the baroreceptor reflex has been studied previously in preparations in which the feedback path was either intact' or broken,' and several models of blood pressure regulation have been proposed."• Physiological processes involved in the reflex control of blood pressure (such as sinus and aortic nerve activity,' changes in cardiac output and peripheral resistance,' and renal and adrenal hormonal changes) have been studied individually. But complete, quantitative descriptions of the overall response and of the individual processes are lacking at present.