Regulation of kidney function

How much urine the kidneys make, and how concentrated it is, is not left to chance - it is continuously adjusted by a small set of hormones responding to changes in blood volume, blood pressure and blood ionic composition. Osmoreceptors in the hypothalamus, pressure- and flow-sensing cells in the juxtaglomerular apparatus of the nephron, and stretch-sensitive cells in the heart's atria all feed into this control system. The three subsections that follow cover, in turn, antidiuretic hormone (which conserves water), the renin-angiotensin-aldosterone system (which conserves sodium and raises blood pres …