hey everyone it's a earth register nurse sorry and calm and today we're going to talk about the renin-angiotensin-aldosterone system also called the RAF's system and as always after you get done watching this youtube video you can access a free quiz that will test you on this system so let's get started what does this system do and what is its whole goal well the rath system what it does is it manages our blood pressure specifically when that blood pressure drops so what it's going to do is it's going to kick into gear and it's going to increase the blood pressure by getting a naturally occurring substance on board in the body called angiotensin 2 so that is the whole goal of this system is to get angiotensin ii activated and functioning to help cause major vasoconstriction in the body because when we constrict vessels we increase blood pressure plus angiotensin ii will help increase our blood volume as well which will also increase our pressure so let's go through this system step by step until we get to the end result angiotensin ii now as we study this really let the names of these substances help you out because it's called the renin-angiotensin-aldosterone system and this is really the sequence of how these substances are released so very first thing happens our blood pressure drops the body senses this and says oh no we've got to deal with this so the sympathetic nervous system is stimulated and remember this is our fighter flight system that helps save our life so these nerves stimulate the kidney specifically these cells called juxta glomerular cells also called JG cells and these cells are stimulated and they will release a substance called renin which is the first part of our system so renin enters into circulation now as it's flowing through circulation it's going to do something it's going to activate a substance in the liver called Angie Oh ten Synod jinn and once the substance is activated because of this Wrentham it is going to turn into angiotensin one now remember we need to get to angiotensin 2 so we have angiotensin so we're in the second part of our whole system name and since this angiotensin is in the system and the vessels it is going to really get this ace involved because we need ace ace is going to help us convert angiotensin 1 into angiotensin 2 so ace stands for angiotensin converting enzyme so it's going to convert it for us and this ace is found on the surface of the lung and kidneys in the endothelium so it's going to convert our angiotensin one to angiotensin 2 now we're here we have this awesome active vasoconstrictor agent in our body that's going to help us increase our blood pressure but how does it do that we need to talk about aldosterone right okay so angiotensin 2 it's gonna act on our smooth muscle vessels it's going to constrict our vessels when we constrict vessels that's going to increase systemic vascular resistance and increase our blood pressure to help you visualize it or understand it think about a water hose when we take that water hose and we narrow it what happens to the pressure of the water coming out it's really gonna increase now another way we can increase the water the pressure coming out of that water hose is if we increase the volume of the amount of water coming out of the house so we go to that faucet turn it up that's going to increase the pressure even more so that's what this angiotensin ii is also going to do so it's not only going to constrict our vessels but it's going to help increase blood volume now how does it do this well it stimulates some other things number one our kidneys are going to be stimulated kidneys are going to start conserving sodium and water at those tubular sites within the nephron and it's influenced by also another substance which is produced by the adrenal cortex called aldosterone which is the last part of the name of our system now Dahlstrom what it is they're gonna do it's going to also cause the kidneys to keep sodium in water and it can also lower our potassium level because the kidneys will start to excrete it another gland that's going to be stimulated because of this angiotensin ii is the pituitary gland and it's going to release a substance called ADH antidiuretic hormone also called vasopressin and what this substance does is it causes our kidneys to keep water so we're keeping water even more water we're gonna keep more water and sodium over here and the kidneys are gonna do that so what it's gonna do is it's gonna increase the volume of blood which is going to increase our blood pressure even more so the end result of this wrath system whenever it is working correctly is we are going to increase our blood pressure now in the previous lecture we talked about ACE inhibitors in these medications what do they do they help lower the blood pressure and right here what ACE inhibitors do they prevent this ace the angiotensin converting enzyme from working and so you don't get the conversion of angiotensin 1 to angiotensin 2 so we have lower blood pressure now let's illustrate this and do a quick recap of this wrath system so it will stick in your mind so we have that drop in blood pressure sympathetic nervous system is stimulated which will send nerve impulses to those JG cells in the kidneys which will cause them to release renin into the circulation when written as president of circulation it's going to activate a substance in the liver called angiotensinogen and this will turn into angiotensin 1 now we want angiotensin 1 to turn into that active vaso constrictor so to do that you have to have a switch is angiotensin converting enzyme I remember this was found on the endothelium in the lung and the kidneys so ACE will turn angiotensin 1 in angiotensin ii and angiotensin ii it's gonna have some effects on the body one thing it's going to do is it's going to cause vasoconstriction so constrict those vessels it's gonna cause the kidneys to keep sodium and water which is going to help increase blood volume also you're gonna have aldosterone being produced by that adrenal cortex and that's found on top of the kidneys it's going to help the kidneys also keep sodium and water but remember potassium will be excreted and then we also have the pituitary gland who is going to produce antidiuretic hormone ADH and that's going to cause the body to keep water all together they want to increase blood volume we're constricting vessels and this angiotensin ii is going to help us increase blood pressure okay so that wraps up this review over the renin-angiotensin-aldosterone system thank you so much for watching don't forget to take the free quiz and to subscribe to our channel for more videos