Hello and welcome to the Zero to Finals podcast.

My name is Tom and in this episode I'm going to be talking to you about the Renin-Angiotensin-Aldosterone system.

And you can find written notes on this topic at zero-to- to finals.com slash renin angiotensin

aldosterone system or in the endocrinology section of the second edition of the zero to finals medicine book

and you can find flashcards and questions to train your knowledge on this content and help

you remember the information for longer at members.0 tofinals.com. So let's get straight into it.

The renin angiotensin-adostron system, or R-A-A-A-S, is central in the regulation of blood pressure,

electrolyte balance, and blood vessel and heart remodeling.

So let's go through the steps in the renin-angiotensin-aldosterone system.

Inside the kidneys, many tiny structures called nephrons

filter the blood and produce urine. The basic structure of the nephron from start to finish

is the glomerulus, proximal tubule, loop of Henley, distal tubule and collecting duct. At the start of the nephron is the glomerulus.

The aphorant arterials bring blood into the glomerulus and the efferent arterials drain blood out of the glomerulus.

Fluid filters from the blood in the glomerulus into Bowman's capsule, the first part of the nephron.

The filtered fluid is called filtrate. This fluid travels along the nephron where various chemicals are secreted and reabsorbed

before eventually it drains through the collecting ducts and out of the kidney as urine.

The juxtaglamyllular cells are found at the aphorant arterials.

They sense the blood pressure in the aphorant arterials and secrete an enzyme called renin,

depending on the pressure.

When there's a low blood pressure, they secrete more renin,

and when there's a high blood pressure, they secrete more renin, and when there's a high blood pressure,

they secrete less renin.

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