Hello dear all student nurses
While talking about hypertension and Antihypertensive drugs, I thought, it would be beneficial if you get an idea regarding how BP is regulated in our body.
In our body, BP is regulated by Neuroendocrine mechanisms. The sympathetic nervous system gives the neuro mechanism for BP regulation, through baroreceptors and chemoreceptors.
Renin-Angiotensin-Aldosterone system is the hormone system, that regulates BP and fluid balance.
How it acts
In response to water or electrolyte imbalance, the Juxtaglomerular apparatus of the kidneys release Renin into the circulation.
Renin cleaves Angiotensinogen (released by the liver) into Angiotensin I
Angiotensin I gets converted into Angiotensin II, by Angiotensin Converting Enzyme, found in lungs.
Angiotensin II acts in two ways
- Angiotensin II itself is a vasoconstrictive peptide, and it increases the peripheral vascular resistance and BP.
- Angiotensin II stimulates the secretion of Aldosterone from the adrenal cortex. Aldosterone increases the reabsorption of sodium and water into the blood and eliminates potassium and maintain electrolyte balance. The increase in fluid volume, in turn, increases the BP.
This mechanism is much important when you deal with the antihypertensive agents, which we will discuss in the next few articles… see you all soon. Have a good study day…
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