assalamualaikum this is today we are starting a new electrolyte that is potassium we have discussed magnesium so if you have not seen it please go back and see the videos so today we'll focus uh on basically what is potassium where it is located and then we'll focus mainly on how it is regulated in the body in tight normal values so let's start a discussion first of all what are what is basically potassium so potassium is basically first important point over it it is an intracellular most common so it is basically first most common intracellular cation of our body fine so from this line it's very evident that what is the location of potassium in the body its location is of course present within the cells so what is its location it is present in the se all cells of our body fine now we will discuss that some of basic introductions over it that what are its normal values it's 3.5 to 5 milli equivalent per liter so you can write 3.5 to 5 millimole or mini equivalent per liter it's its normal values fine now let's start on the regulation of potassium in the body and that is basically our main topic potassium ion regulation in the body fine so yes let's just start a discussion first of all that is very important is that how potassium enters our body first we'll uh take that suppose this is our stomach this is the intestine this is our large intestine here so here goes i think it's a bit bad drawing but okay this is i have tried to made git tract first important organ from where the potassium ions through our mouth enters the body in in the diet and is absorbed from the small intestine and this is the role of git tract so it absorbs its two plus it excretes it too fine and its exclusion is just you can say nine percent second organ that we're going to discuss is the kidney that is very important this is its adrenal gland this is the whole kidney pelvis ureter so we're talking about the whole kidney fine kidney plays a major role in the excretion process of the potassium ions and yeah and third which is a it's an organ it's a process that sweat so some of the potassium ion is lost through i think sweat should be blue but ignore this brown color now so yes this is sweat so a small amount is lost in the sweat okay so i made these three organs so now how it its whole regulation is occurring is that okay first of all we have eaten a diet containing potassium and potassium comes through our mouth into the git tract from there it is absorbed fine now only nine percent of it will be excreted by the git tract and major 90 percent of the potassium whether it will be increased reabsorbed or less reabsorbed and resultant they will be excretion of potassium which is basically called the secretion of potassium in the tubular fluid so it occurs from the kidneys moving on to the sweats only just a few percent you can say one to two percent that is excreted in the sweat so now we'll discuss that this is the whole regulation basically we'll major uh focus on the kidney for this because the major regulation mechanisms they occur within the kidney so where indicating a question arises that okay in the kidney but what is the location where the major regulation occurs in the kidney so let's just make a nephron and see how is potassium moving in the nephron fine so imagine this is the bowman capsule i'll make a very simple one this is the proximal convoluted tubule here is the loop of henle moving down this is the thick ascending limb of loop of henle and here is the distal convoluted tubule up to the collecting duct so here is a effect arteriole coming and this is the efferent arteriole fine so now important part starts that suppose i'm making it with green whole our potassium that was entered through the diet in the git tract absorbed from there and entered the blood that potassium which is now circulating in the blood comes to the renal artery of course back to the heart and from heart through the left ventricle it comes to the renal artery and renal artery to the efferent arteriole now this potassium that comes here is at this point where this is a point where filtration occurs at the level of bowman capsule and the glomerular capillaries their filtration so here potassium ion is freely filtered so almost all that is coming is filtered here fine now in this proximal convoluted tubule 65 percent of the potassium is reabsorbed back into the blood in this thick ascending limb of loop of la the remaining 15 percent is absorbed back into the blood now these absorptions they uh normally occur whatever the blood will come there these potassium mine will be fully filtered 65 absorbed here 15 percent absorbed here so these absorptions will occur but the question rather than your mind that what is the site in the kidney where it is regulated means excreted so this is uh the distal converted table and the collecting duct so basically it's the distal convoluted tubule and the early collecting duct where the potassium is secreted i repeats its secretion means what is secretion whenever a fluid or a substance or an iron it moves from the blood into the tubule to be excreted in the urine then it is called secretion fine so here they will be secretion of the potassium into the tubular human and some into the from the collecting ducts also now the amount that is secreted here is basically dependent on the amount that is present in our body so this these two levels they will perform the action of tight regulation of the potassium levels depending on the need because of course if i have excess then i can easily lose it because i don't need that excess amount in my body so this is a very basic concept that you should remember so now we'll just discuss a cell of distal convoluted tubules and see how it is regulated there fine so i'll draw a cell in front of you just a small cell of this distal convoluted tubule it is drawn here down so suppose this is that cell of distal convoluted tubule this is the blood vessel moving and this is the tubular lumen now now we're going to discuss that how the movement of potassium occurs how the secretion of potassium occurs and what are the factors that influence that secretion and i'll just remember i help you memorize in just a few minutes by just seeing this diagram so please just listen very carefully it is a very very very important point that will help you in all the whole story of potassium so this i have made the lumen of the tubules this is blood of course capillary so this is the distal community tubule cell now the part of the cell that is towards the lumen we call it the luminal side and the part that is toward the blood vessel we call it from remember from b blood all towards the body so by b you can easily remember that it's the beso lateral side of the cell just to remember for a quick recall now what is happening here that from the lumen we know that we have to absorb sodium from the uh lumen into our body so here is a channel this is called e n a c channel so it's the name of the channel but what it does is that it absorb potash sodium ions into the distal combinated tubular cell to this channel now on the basolateral side there is a pump very common pump you all know it's sodium potassium atps pump now what is its name sodium potassium atpase pump now what is the function of this pump what it does is that this sodium ion which is absorbed from the tubular lumen into the cell it then moves here so three sodium ions are pumped into the lumen in exchange for two potassium ions coming into the cell fine so these two potassium ions come into the cell which is then of course secreted in this lumen by of course the channel which is its name is rom k so this is the name of that channel this potassium is then secreted in the lumen here so this is basically what is happening here in the distal convoluted uh cognitive tubular cell and now this is how sodium is absorbed and potassium is secreted now the amount of this potassium that is secreted here in the tubular lumen is dependent on a number of factors now we will discuss those factors so what are the factors to remember there are three factors on the basolateral side of course in our blood related factors and two factors are the lumen related factors now what are the blood related factors just remember or recall a simple theme that whenever something is in excess in my body i'll just write here whenever something is in excess i easily lose it because i don't want it fine just a simple mnemonic to uh remember it very easily now what will be in excess first of all we want to we are losing potassium here so of course when there is increased potassium in the blood we easily lose this potassium so this potassium secretion rate is increased if there is hyper kalemia okay now second condition is when there is increased ph first is this second is when there is increase ph now what is increased ph means that if there is alkalosis in the body it also loses the potassium along with the hydrogen no sorry it loses the potassium out of the body and exchanged with hydrogen coming back to the body so yes that's important is that alkalosis it causes the potassium to lose out of the body and third important factor is aldosterone so we have already studied it's in our physiology couple of years back so what is aldosterone it is a hormone that is released by the adrenal cortex from zona glomerulosa and what it does is that it absorbs sodium and excrete potassium it absorbs sodium and excrete potassium from our body so when this hormone is present in excess there will be increased excretion of potassium which will lead to hypokalemia so three factors i explained here what hyperkalemia so increase potassium increase ph increase aldosterone coming on to these new one side factors what are those factors first factor is the luminal charge so the charge in the human now here in the digital community tubule there is the negative charge in the new one so i'll just make this small negative charge it is negative charge in the human now any drug that will or any substance that changes this luminal charge i'll write here negative luminal charge changing drugs or anything who alter the negative numerical charge now what will happen if this negative lumia charge is present that is present normally pressure can easily excrete here so if th this this luminal charge is altered then it can also cause change in the potassium excretion fine and another point is the sodium amount of sodium and water that is reaching the distal converted tubule and we know in the digital commodity tribute there are juxtaminer cells macular densa cells that senses them and accordingly gfr is adjusted so yes this these are the two factors that influence the potassium secretion in the lumen and hence out of the body so here we have discussed the whole potassium regulation how it is regulated within the kidney and we have discussed the factors that influence those regulation uh mechanisms now talking about the two others there are left that is git and sweat gid is that if there is excessive we can say that if there is excessive diarrhea now these are the conditions which we will discuss in hyperkalemia in more detail but yes any condition that was increased loss from the geriatric diarrhea or lexatives or enema or anything so or any condition that like vomiting so it can these all can lead to excretion of potassium from the body and hence hypokalemia can occur basically the excretion is occurring through git by these roots and in the sweat sweat is like when the patient is doing excessive workout in hot climate then he'll sweat a lot and in the sweat some amount of potassium is excreted so this this is the whole brief overview of the regulation of potassium ions in the body three major organs just a quick summary three major organ that are controlling it the gid tract from where it is excreted just nine percent in the kidneys ninety percent is excreted and in the sweat a small amount one to two percent is excreted in the sweat mechanisms i've explained here and uh the factors are the hyperkalemia alkalosis aldosterone now yes one point here that these factors which i discussed before this hyperkalemia and ph these are the all factors that cause increased loss so opposite to these if it's hypokalemia or acidosis or decrease aldosterone then it will cause increased retention of potassium which which can cause of course hyperkalemia in the body plus these luminal changing luminal charge changing drugs like suppose if the patient is uh taking this is performed by the potassium spilling diuretics which are called amyloid so it changes the luminal charge and they can cause then hyperkalemia so yes this is how the potassium is regulated in the body and just at the end the tight regulation occurs in distal community table and early collecting ducts of the kidney so i hope many of the concepts of the potassium regulation will have been uh will be clear now and this video will help you out if it does so so please just like share and subscribe and keep supporting thank you so much alafay see you in the next video