Renin- Angiotensin-Aldosterone pathway

Image adapted courtesy of https://commons.wikimedia.org/wiki/File:Renin-angiotensin-aldosterone_system.png under the GNU free documentation License

The renin-angiotensin-aldosterone pathway is very important in the regulation of salt and water.  The kidney stimulate renin release when blood volume is low. The renin then triggers the release of angiotensin I which is converted to angiotensin II by the ACE enzyme.  Angiotensin has many function as you can see from the diagram, it stimulates the release of the antidiuretic hormone (ADH).  It also aids in the release of aldosterone from the adrenal gland. Aldosterone increases sodium and water reabsorption at the distal tubule along with Angiotensin II. These different components of the system feedback on one another.