11.7: Renal Innervation

While the glomeruli, efferent arterioles, and renal tubules lack innervation, the kidneys themselves are intricately linked to the ANS. Sympathetic nerve fibers are extensively distributed near interlobar, arcuate, and interlobular arteries, afferent arterioles, and the vicinity of the vasa recta. Additionally, cholinergic fibers are present within the kidney. Interestingly, despite this robust neural network, there is no evidence supporting the existence of a basal sympathetic vascular tone in the kidneys, which implies that the renal denervation process does not lead to an increase in renal blood flow. However, intense stimulation of the sympathetic fibers can lead to marked cortical arteriolar vasoconstriction in highly stressful situations. Consequently, this constriction diverts blood flow to the juxtamedullary nephrons, playing a crucial role in maintaining kidney function during periods of extreme physiological stress.¹⁴

 

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