Figure 1.

Schematic of the general mechanisms for blood pressure regulation. Arterial pressure is the product of cardiac output and systemic vascular resistance, parameters regulated by neuroendocrine signals which control cardiac, renal, and vascular function. Negative feedback pathways, depicted by dashed lines, are central to the maintenance homeostasis. Various sensors of arterial pressure mediate feedback by modulating sympathetic and parasympathetic tone; thereby, influencing many elements of cardiovascular function. The kidneys play a major role in the regulation of blood pressure through the RAAS, controlling pressure-natriuresis and pressure diuresis-mechanisms which determine fluid volume. Autocrine and paracrine mechanisms allow individual tissues to autoregulate vascular tone and blood flow through local release of vasoactive substances. Ach, Acetylcholine; ANP, Atrial Natriuretic Peptide; Epi, Epinephrine; NE, Norepinephrine; NO, Nitric Oxide; RAAS, Renin-Angiotensin-Aldosterone System [Concept derived from Cowley (15)].