Cardiorenal Physiology

Abstract

The heart and the kidneys are intimate partners in handling pressure—arterial blood pressure. The cardiac muscle and renal nephrons both receive sympathetic nerve inputs which serve as part of the integrative, wired connections between them. The kidneys also secrete hormones, renin and erythropoietin which are “wireless” hormonal signals that maintain the blood volume. Arterial baroreceptors that monitor blood pressure/volume are found in the carotid artery/aorta and the preglomerular renal arteriole. There are homeostatic linkages between sodium balance, blood volume, blood pressure, and urinary excretion of sodium. Regulated renal tubular secretion of potassium and excretion in the urine (“pee”) is essential to maintain normal cardiac pacemaker activity. The three Ps here (pee, potassium, pacemaker) are bound together for life.