The RAAS operates through a series of steps that involve the activation and interaction of various components:
1.
Renin Release: In response to low blood pressure or low sodium levels, the juxtaglomerular cells in the kidneys release renin into the bloodstream.
2.
Angiotensinogen Conversion: Renin catalyzes the conversion of angiotensinogen, produced by the liver, into angiotensin I.
3.
Angiotensin I to Angiotensin II: Angiotensin I is then converted to angiotensin II by the action of
angiotensin-converting enzyme (ACE), mainly in the lungs.
4.
Actions of Angiotensin II: Angiotensin II acts on various tissues, including the adrenal glands, to stimulate the secretion of aldosterone. It also causes vasoconstriction, thereby increasing blood pressure.
5.
Aldosterone Function: Aldosterone acts on the distal convoluted tubules and collecting ducts of the kidneys, promoting sodium reabsorption and potassium excretion. This leads to water retention, increased blood volume, and elevated blood pressure.
