Functions of Kidneys | Physiology and Structure | Dr Najeeb

today we are starting with the renal system right first we'll start with the renal physiology and once we have done a good understanding of the renal physiology we'll build over that the disturbance of linear function that is renal pathology internal physiology means that how the renal system functions normally and when the system of the original system is Disturbed in its function and structure we say this is renal pathology and after that we'll go to the renal uh pharmacology so before we really delve into details of renal system well I will discuss a very very basic concept later on of course we're going to very big detail how the nav front Works how every part of method works but first of all we'll talk we'll start our lecture with the very basic right number one what are the functions of renal system functions of renal system this is the first aspect which we will cover first of all right and second aspect I will I would love to cover is that hormones and kidneys hormones and kidneys after that I will go really into detail how the nephrons handle different substances right during urine formation so what are the normal functions of kidney yes please okay we start like this that kidney can do number one it has some excretory functions right there are excretory functions everyone knows even a small child knows and Mama and Papa tell the urine is coming from the kidney right at it eliminates the waste product number two the renal system is concerned with regulatory functions we'll talk about what are those regulatory functions regulatory regulatory functions right there are excretory functions there are some substances which are excreted through the kidney the waste products we'll talk into detail then the other substances which are regulated the balance is regulated in the body by the Forgiveness then there are endocrine functions of the kidney kidneys and endocrine organ as well so endo crying functions and of course at the end we'll come to the last most important function I don't know somehow doctors or students don't remember that and that is the metabolic functions of the kidney it's a metabolic organ as well metabolic functions of the kidney it means that kidneys are excretory organs they are regulatory argon for certain substances in the blood their endocrine organs as well as the metabolically active of course so first we'll go into detail that what are the substances which are excreted through the kidney right what are the substances which are excreted through kidney in the next section we'll discuss about the hormones first of all kidneys kidneys are supposed to split the metabolic waste products like urea and Syria so first thing is metabolic waste products what is the second function of the kidney second excretory function is of course when you are taking food lot of metabolism is going on and during those metabolic functions some waste products are produced and many of these waste products go through urine at the top you must remember urea and creatinine is that right here when we talk about metabolic waste products and I've mentioned that there is urea and creatinine are checked into urine to see the renal function you know this that if your renal function is Disturbed then in the blood urine creatinine level may be disturbed you know it that's great I want to know out of these two for example a patient comes to you and his renal function is already known that linear function of the patient is Disturbed you would love to do a serum urea level and serum creatinine lava but if you have to do one test not both tests which test is the gold standard for renal function written in uh what about you Julia okay Shirin thinks that it's created in a Boston Celia you are with whom you are with Julia what about wakas you are also urea man urea so what we decide that majority is not always right is right the gold standard for the renal function is creatinine write it down and put a star with it if you really want to know why urea is wrong I can explain that or you are not interested in explanation now you are already very much sad okay let me tell you it's important to tell actually the creatinine level in blood is mainly dependent on renal function if kidneys are not doing working well GFR is not there filtration is not there created and start going up of course with that urea also goes up but Julia has a problem the urea level goes up not only in the renal dysfunction but urea level goes up even many other conditions for example if you develop you undergo sphere or you can say too much sweating right and you dehydrate then what will happen everything in the blood will concentrate and jury is specifically concentrate so urea level may go up not only in renal failure urea level may also go after you when you have sea severe dehydration whatever the cause or your sphere vomiting your sphere diarrhea right or you have polyurea you are losing water out of the body vomiting you lose the water in diarrhea you may lose a lot of water in Polish urea you lose the water and or excessive sweating under all these circumstances when you're losing a heavy amount of water out of the body you are rapidly concentrate those are right so UDF may be high when kidney may not be so much Disturbed simply by dehydration then another thing you know urea is a breakdown product coming from amino acids everyone knows it right if one day you go to a special party and there's a competition who eats more chicken and who eats more beef and who eats more mutton and maybe Mr vakash sidhu he wins the wins in the party he hits everyone's mutton and he becomes the champion but after a few hours urea level in the blood will go High because he has taken too much proteins so a lot of amino acids are breaking down and util level will go up I hope his kidneys will be still okay you get me so the point which I want to put in your mind is that when you go to the you have to you know correlate the basics of the clinical that when we are talking about urea and creatinine usually when kidney fail both go up but urea may go up in the blood even in those conditions when kidney is functioning okay like high protein diet like dehydration right and there are some other conditions also so Julia is not the gold standard for renal functional impairment so renal failure the gold standard is creatinine is it clear okay so we were talking about that kidneys involved and some excretory functions and in this these descriptive functions most important is their kidney should get out of the body all the metabolic most of the metabolic waste products then any other substance which is excreted out of the through urine do you know any other substance yes Dr naznin any other substance you can imagine in your life up to now you've studied a lot of medicine that some substances are going out through the urine yes okay he's a great man he says water goes out of the body listen don't write it first we agree water goes out but the reason is that water is not usually a scratchy product actually kidney gets rid of the water while regulating the water balance if there's less water in the body kidney will conserve the water if there is excessive water intake kidney will flush out the water so more appropriately uh it should be regulatory function of fluid balance in the body your understanding so we'll discuss that here so I'm talking about truly waste products which we don't want to accumulate in the body why don't you tell me please why don't you tell me something very important like drugs do you think all your life you have taken so many drugs all are stuck in your body no they go out of your body right either they go through fecal root or they go through urinary root so you have to remember that renal system is extremely important in getting rid of drugs many drugs otherwise you know you have been taking aspirin and so many drugs you have taken from your childhood up to now maybe this this man a bus you will become just bag of the tablets but thank God not because you keep on taking the drugs drugs are altered in the body usually alteration of the drug is called biotransformation so drugs undergo biotransformation and they become more water soluble and then they go out of the body right so other do you know that uh drug metabolites which will go out through urine of course there should be water soluble there should be water soluble here there's an interesting situation that anything which has to go out of the body through the kidney it must be water soluble anything which has to go out of the body through kidney it should be water soluble right who is having the real idea that you know okay let me tell you something interesting I'll make a small diagram and Mr Sean will highlight this suppose this is your okay I will make this diagram on this side let's suppose that here is your git right here is your liver I'm going to tell you how kidney handles along with the liver and other circulatory system your and this is the Nephron you know kidney has a lot of tubes these specialized tubes are called I will these specialized tubes which are present in the kidney they are called nephrons nephrons right how many nephrons you have in your kidney Dr nazanin you know never a sit and count it okay what about you shrin how many nephrons you have in one kidney in one kidney yes this is a very important concept because the whole renal physique look no when you say digital converter tubule proximal convoluted tubules you are talk talking about about the parts of the Nephron you get it nephron is an epithelial tube I will discuss into detail later but whole renal physiology is the mostly about the functions of nephron how the nephrons work so good strong should know at least some idea there are how many nephrons we have in one kidney yes please you know idea yes oh he knows that he's millionaire as far as the France are concerned yes we have about uh 1.1 million nephron and one kidney so you can say 2 to 2.5 million nephrons you have working in both healthy goodness is that right I've just drawn one nephron nephron is made of what substance it is made of connective tissue cells or it is made of epithelial cells or it is made of what type of cells it's a tube which is made of lot of epithelial cells this is a tube which is made of epithelial cells and lateral lateral lectures we'll go into detail of different parts of the Nephron and how epithelium modifies along the different part of nephrons for a while you just trust me that nephron is just made of epithelial cells is that right and even this is also having epithelial cells this is Bowman space right this is the filtration unit now what really happens that most of the drugs which come into your body let's suppose this is a liver cell this is a liver cell mostly what happened that you have taken a drug orally and this drug is highly lipid soluble you have taken a drug or a substance orally and this is highly lipid soluble because it is lipid soluble it will dissolve into mucosal membranes and it will go to the through the portal circulation it will pass through liver and then it will go to the general circulation now this is lipid soluble drug coming into your blood now the point which I want to put that lipid soluble substances can cross biological membranes lipid soluble substances can cross biological membranes what are the biological membranes like Gat mucosal membrane like blood vein barrier blood brain barrier like placental barrier these are different examples of biological membranes substance which is highly lipid soluble that will easily absorb from the git and go to your circulation now you imagine that let's suppose this substance was supposed to work on these cells every drug has to work on certain area let's suppose the substance was supposed to function of these cells and bring some biological changes in the body now the point which I want to highlight now that how this substance can go out of the body once it is entered how it can go out of the body right this is liver and here is your suppose I make two hepatocytes right and here is your what is this system suppose building drainage systems you know bile system drain into is that right now listen carefully this substance again the substance has gone into the body right and it is performing its function on the target tissue is that right now this substance should stay forever in your body or should go out of your body it should go out we do not want drugs to stay forever in our body now we want it to go out if it remains lipid soluble now listen carefully one way is it can go out through liver other ways it can go out through is that right let's see if this is lipid soluble it enters into liver cells and if liver cells by special pumps the flowers help push this drug into building system so that it should go out through bile you know it will never go out because it is highly lipid soluble again from here it will come Out Come Back you understand it because drug was highly lipid soluble even if from hepatocytes shift to the bilary drainage system through the bile it will come to the git of course leave one of the jit but because it is lipid soluble it will again absorb from the JD mucus and back to the body so do you think the highly lipid soluble drug can can we get rid of them through this hepatible system we cannot now we'll try other root what is the other root okay drug is here now it is again highly lipid soluble so if it is highly lipid soluble you know epithelial membranes are epithelial cells have the membranes made of lipids lipid bilayer you remember every cell has a lipid bilayer so epithelial cells are also having lipid bilayer if this is highly lipid soluble it will dissolve into membranes of epithelial cells and again go back to the body so as it is passing forward it will come back to the body because it is a lipid soluble so it can dissolve into epithelial cells membrane and come back to the body do you think then it has to go down into urine no what is the principle I am trying to highlight when drugs drugs or hormones or any substance which has which is present in your body if it is highly lipid soluble we cannot get it out through more two most effective systems the two basic two basic of most effective system will fail one is the appeto Builder system other is the renal system how we can really get the substance out of the body one of the best ways convert this lipid soluble substance into water solubles now vakas will tell us how we can convert a liberal soluble substance into water soluble substance for example this is a lipid soluble substance and here now it is water soluble substance how is this lipid soluble substance is converted into water soluble substance what is the method anyone who knows have you ever studied pharmacology something called pharmacology yeah we keep on learning about the drugs how they go out of the body they met applied this is a very very basic principle and drink more water hey what excellent you know the one there are two ways to convert lipid soluble substance into water soluble simply this is lipid soluble substance and you add to it highly charged molecule let's suppose this molecule is highly charged name of this molecule is suppose glucuronic acid it's the derivative of glucose many hepatocytes produce you know petrocytes can produce glucuronic acid and this is glucuronic acid is highly charged molecule and this highly charged or polar cap you can attach with lipid soluble and now this complex okay it will become sad now right it is having a highly glucuronic acid or any other substance it is now fused with any substance in the hepatocyte and with the substance is highly charred and so this new complex is highly polar because this new complex is highly polar so it becomes water soluble the such reactions are called conjugation reaction because one molecule is conjugated with the other molecule have you heard of it conjugation reactions and the drugs they mentioned this drug or toxin undergoes conjugation reaction it may conjugate with the glucuronic acid it may conjugate the sulfates and many other products is that right so it becomes water soluble this is one way another way is also another way to convert lipid soluble substance into water soluble is that from the substance you bring out some highly polar group this was the tongue of the molecule and it was previously hiding if tongue is highly charred it bring its tongue out what I mean by this that you are having this is a drug this drug has this component which is highly charged but normally it is hiding in in its structure so it looks like leopard soluble but when this drug passes through the liver hepatocytes exposes charged molecule component and when this charge component is exposed this becomes water soluble or in this example until its tongue is in tongue is one of the special group of chemical group related with this molecule until that tongue is in or that highly polar chain is n uh this is lipid soluble but when it passes through the liver it converts into more polar compound this is another way this is another way that this converted to more polar compound not by addition of something new but simply by exposing its own polar generate this is how substances get polar now if a substance gets polar look here I make this that now suppose this substance has is polar this was lipid soluble substance this was lipid soluble substance right and this lipid soluble substance has been converted in the hepatocytes into a polar compound these processes are called what are the name of such processes bio transformation transformation in the molecules within the biological system changes in the molecule within the biological system so what are these called biotransformation reaction have you heard of them then it tells you something interesting in you have heard that the biotransformation one reaction and their bio transformation two reactions heard of it in biotransformation one reaction right molecule is forced to express some inner inner child group or it is modified to express charge group this is biotransformation one reaction this is biotransformation bio transformation type one reaction but when you lipid soluble substances are added or conjugated with another highly polar molecule these are called bio transformation two reactions this is a very basic Pharma the biotransformation one reactions first of all what a bio transformation reactions biotransformation reactions are very simple reactions ah which alter the molecular structures within the biological system right in the liver most of the drugs pass through biotransformation one or biotransformation two reactions when in the liver drugs are passing through biotransformation one reaction they expose more polar molecules they're modified in such a way right but when in the liver drugs are passing through biotransformation type 2 reactions they are conjugated with more polar compound and a very interesting news many drugs pass first through biotransformation one reaction and then sequentially the pass through byronounce formation two reactions first molecule bring the child tongue out and then you put the cap which is highly charged and it becomes super polar water soluble compound it's a very basic thing we should learn in the very first lecture of Pharma how the body is dealing how body is going to get rid of the drugs they are not there to be accumulated forever right now this molecule is what polar compound now our lipid soluble substance has been converted into Polar compound because it has been converted into Polar compound now it is the discretion of hepatocyte that this can this polar compound can go out of feticide easily no because of battle sites are again made of lipid membranes So within the hepatocide even lipid compound convert into Polar compounds these polar compounds are trapped within the hepatocyte now where they will go will they go to the blood suppose this is circulatory system on one face of hepatocyte we have blood on other phase of pesticide we have bile now it is the pure discretion of hepatocytes that some substances hepatocyte throw into actively because they cannot dissolve into membrane now hepatocytes will need active transporter they will need special transporter and transport this substance may be into the bile or in some other examples it will use some other type of Transporter and pump this substance because this is trapped it will not diffuse out easily so pump the substance into circulation so these are the hepatocyte membranes which decide that once a compound you could not understand it let me tell you what is happening let's focus this area especially what is happening that this was a lipid soluble molecule by biotransformation reaction which has been converted into water soluble molecule this water soluble molecule is no more lipid soluble so it cannot dissolve diffuse through the membranes of hepatocyte so such molecules which are biotransformed into more polar compounds and water soluble compounds they are trapped within the hepatocytes now it is up to peptocytes hepatocytes on one side have while running boundary system running on other side hepatocytes have sinusitis running which are the blood system running is that right now from the hepatocyte here is the Builder system and here is the blood system now it's up to me that difference of some substances I actively transport and to build a system and other substances I actively transport into blood system and still some other substances I actively transport into both systems now it depends on that if the substance is actively transported into Builder system this highly charred molecule it will come down and when this will come down into this area do you think this highly charged molecule can dissolve into now so only destination is flash system is it right because it cannot reaps up from mucosal membrane so we got rid of this compound out of the body is that right this is one thing second thing is if it it has opted F5 has opted to throw this compound into circulatory system then what happens this uh compound from the circulatory system will easily filter into okay not you can say nephron now let's be more technical this substance will filter into nephron but once it filter into nephron do you think the substance can dissolve into these lipid membranes of the epithelial cells it cannot so where the where is the only destination urine I think urine comes out of kidney these days right so what I'm talking about that this is how we can get the substances out through fecal root or substances out through urinary road now I will brief all of it because it's a very very important concept you must have studied in physiology lot of hormones if someone asks you hormones once they are produced are they there in the body forever no for example you become angry I mean a friend should adrenaline short they are from do you think there have been a friend should remain in your blood High forever no where it goes it bio transforms into more lipid highly charged molecules then most of the biotransferring products of epinephrine they go through urine is that right so if you have studied Endocrinology it must be clear to you that how these hormones which are produced in the body go out of the body again all of those compounds are converted into water water soluble system right in the same way all the drugs you take if they're going out of the body with few exceptions like some gases go out through the lungs like in aesthetic gases but most of them either go through the fecal root or they go out through your energy root or a fecal root is usually called hepato Delray Road is that right that is called hepato Delray road now another question which is there let's go back toward in the same way why lever is busy in this sense pharmaceutical companies were not there one million years back am I right there were no many drugs so-called drugs which we have now so what liver was supposed to do then excellent because you know lower animals they keep on eating anything they don't realize you have seen cow does it sterilizers or microwave its material now it keeps on eating everything and liver evolved because most of the substances they pass from the git through the liver to the circulation so liver was a major detoxifier system and it is still major detoxifier system right that liver has a responsibility to convert the lipid soluble substances or toxins or drugs or other substances into more water soluble substances and then if a better side threw that substance into building system they will go out through petability system or hepatocytes through such substances into a circulatory system they will go out through urinary system am I clear now we have discussed that Many metabolic waste product go out through urine as well as many many drugs go out through urine especially there more polar metabolites is that right so we can say there are many drugs and third substance which goes out third type of substances like toxins many toxins which also enter in your body right not all of the toxins but many toxins will go out through urinary system do you have any question here no now very briefly what are the special regulatory functions of the kidney what are the special regulatory functions of the kidney up to now we have discussed the excretory functions of the kidney now we are going to talk about regulatory functions of the kidney they regulate balance of certain substances in our body first of all kidney is very well known to regulate the water balance all of you know that if you take more water it will pass out more water if you take less water kidney wheel comes out of the water we'll we'll discuss in detail later how kidney makes tell you to urine and concentrated urine but it is very important for water balance then it is also concerned with electrolyte balance it is also concerned with Electro light balance electrolyte balance serum electrolyte balance really depends on renal function good renal function right and third regulatory function is yes please that is also extremely important kidney plays a major role along with the lung and that function it regulates something in your body so that your enzymes work well because enzyme work on a specific pH so kidney is regulating acid base balance again there will be three hours lecture on this three or four hours lecture that how kidney is regulating the acid-based balance in your body and how kidney diseases produce acidosis and alkalosis but we are just laying down the foundations today fine so kidney is concerned with water balance it is concerned with electrolyte balance it is concerned with acid-base balance is that right okay about the electrolyte I don't know I'm a bit sensitive or why because good students should know at least the balance concentration of few important electrolytes what is the sodium concentration in a normal person in the blood sodium level in the normal person yeah of course in the blood yeah 140 Watt 140 kilograms milligrams machine guns yeah 140 you should always remember units we are doctors yes 140 Watt millimole per liter right anyways good still he should get the credit he remembers 140. sodium is 140 Milli mole per liter we can also call it 140 Milli equivalent per liter but you know our body has not read the books so it's little bit fluctuate isn't it so truly speaking normal sodium level should be considered 135 to 145 Milli equivalents or millimole per liter same thing five unit up or down is well tolerated is that right when you are in the junior classes you should remember central figure but as you become more senior you should know the normal range because you are going to be a doctor and you must know when to consider your patient normal and when should we considered the electrolyte imbalance has occurred right so it is about 135 to 145 Milli equivalents or millimoles per liter what about potassium level normal potassium level in the plasma or blood yes Mr vocas is trying to say something 60 to 80 you will find this level normally in the graveyards right I want a living human being what is the level of potassium in living human beings who are normally functional is that right normally functional yeah how much I don't know he has said low or high five words thanks yes you always mention the journals with it right that's good potassium is again good boys should remember the whole including the good girls uh range 3.5 to 5.5 millimolo Milli equivalence per liter is that right that is too dangerous you know about when people reach at the level of 7.5 or 8 usually they are dead that's not right so I don't know maybe you have been putting the potassium into dead body right so anyway no problem you are going to work such formulas you know it is being recorded they will catch you right with your intentions okay now what we are talking about that I'm just kidding right so 3.5 to 5.5 Milli equivalent per liter is the normal range of potassium level and every good doctor should know well but you know your central CPU become really tired and if you want to remember one of these value which is more important Dr nazanin will tell us if you have to remember one of these value for example you are those type of doctors I cannot remember to already have to remember many other things in my life and you are left with to remember with one which you will choose in clinical practice for patients life and death matter both are important but which is more important yes potassium level or sodium level sodium level yes potassium level yes sodium level yeah potassium this time majority is Right potassium level is extremely important again because was eventually right somehow so actually potassium level is more important you know why it is already little fluctuation potassium beyond the normal value kills the patient sometimes right we say if patient has a potassium level you cannot study renal system without knowing electrolyte why I'm telling you these things because later on I will tell you how nephron is dealing with electrolyte and why it is so important look if this level is less than 2.5 right we say the hypocalemia and if it is more than 6.5 we say there is a hyperkalemia and hypokalemia sphere hypokalemia as well as severe hyperkalemia both hand precipitate dangerous cardiac tachythmia and kill the patient how they produce tracheurysmia will talk at later right so if you remember only one please remember potassium level rather write it down that out of whole electrolytes in the body the most important to remember the level is potassium after that you can come to others like sodium or calcium sodium level 135 to 145 Milli equivalent per liter but it can be tolerated even if it falls to 125 or it rises up to 155 is that right but little fluctuations in potassium are going to kill the patient so you have to be very very sensitive when you look at a report of the laboratory right lab report from the patient that what is the potassium level and again who is the master regulator of potassium level this is your goodness you know potassium is control at Exit level it is regulated in your body at exact level it exists through it enters through oral cavity you know you take a lot of food which are very very rich in potassium and it goes production goes out through mainly goes out through urine is that right do you think you are all the time wearing potassium into food never bothered no one bothered isn't it why because kidneys so Master regulator of potassium handling that if you take more potassium it will pass out more potassium if you take less potassium it will pass out less potassium until kidneys are absolutely healthy and their function is not altered by the drugs in future I will tell you many drugs change the function of the kidney is that right again listen there are some substances their control at the entry level for example the classical example is iron you know in many food there is iron only you absorb the iron which is required extra iron is lost into fecal matter so it means iron absorption is regulated at entry point what is the entry point GID mucosa is that right usually in a healthy person we don't absorb extra iron even if we put on the diet extra iron it will be lost in fecal matter but potassium is not well regulated at entry point G80 mucosa usually whatever potassium is coming most of it is absorbed where it is well regulated at Exit point that is it exists through kidney so nephrons later on I will discuss us so Master regulator of handling the potassium whenever the sense potassium is going up the start secreting potassium in higher amount into urine and whenever this sense potassium is lower the body they reduce the waste of potassium we'll talk about that later in detail so anyway here we also know there is something called chloride isn't it if you know the levels of two Cate ions at least you should know the level of one anion what is the normal level of chloride it's around 100 it is around 100 Milli equivalents per liter up to 105 is okay is that right so you can say around 100 Milli equivalents per liter but of course little up and little down is normal range and what about the bicarbonate level of bicarbonate is also electrolyte isn't it am I right by car it is The Alkali of your body the base of your body playing a major role in acid base handling and pH of the body yeah what is the normal level of bicarbonate ions no one knows I'm dealing with the doctors future doctors okay yes any estimate but not like graveyard estimate any guess that's the graveyard totally speaking to go back there 135 is a very high level of potassium in a dead body you have to inject potassium uh it effort is possible but it is alkalosis during the day it's less than that before you tell me something new it is somewhere between 22 and 28 Milli equivalents per literal per liter or 25. on average is that right okay this was some talk about the electrolyte balance so this is a kidney which has to control the sodium balance it has to control the production balance it has to control the on the right balance it has to manage the bicarb balance and of course you should not forget your front which keep you strong that is calcium is that right calcium balance is also controlled by kidney and many other organs that we'll discuss sometimes else but what is the normal level of calcium in the blood because very soon we'll leave the renal physiology go to the renal pathology then we'll talk about these electrolytes that Disturbed so it's good at this point we must know what is the normal level of calcium about 2.5 millimole per liter about 2.5 approximately milli mole per letter right so we have discussed about few excretory functions of the kidney and some regulatory function of the kidney if you are not tired we can continue with the endocrine function of the kidney should we continue Okay so so kidneys and endocrine gland as well how do you define an endocrine gland just how do you define endocrine gland is any collection of cells which produce a substance and release into blood and that that substance is carried away from there and act to another group of cells one group of cell producing a product which is passing through the blood and altering the biological action of another group of cells there's this is the definition of endo endocrine glands and hormones am I clear so kidney is an endocrine gland as well right right kidneys endocrine or left both okay that's good he knows it so what are the hormones which are produced by the kidney yes what are the hormones which are produced by the kidney erythropoietin excellent first of all erythro ating excellent second is renin this is also produced by the kidney then another hormone which is produced by the kidney adhs acting on the kidney I think up to few minutes before ADH was produced by the hypothalamus and stored in the posterior pituitary it is still doing the same thing okay it acts on the kidney hormones from the kidney are different and hormones acting on the kidney are different so I'm talking about hormones from the kidney produced by the kidney and acting somewhere else in the body so we have discussed that there are erythropoietin and there is ran in and any other hormones which are produced by the kidney have you heard of prostaglandins many kidney cells produce prostaglandins which regulate the intra-renal blood flow blood flows within the kidney and even outside right so but mainly in the interaction also prosta glandins production is that right it produces prostaglandins that produces ran in prostaglandins are mostly vasodilators renin work with you know it that will convert angiot and Cyanogen into Angiotensin one which is converted into Angiotensin to an angiotensin two really forces the release of aldosterone plus Angiotensin II produces Vino construction artery Construction Plus endurance into stimulates sympathetic nervous system Angiotensin II produces thirst and many other functions right so they are so angiotensin two levels go up when in the blood renin level goes up again we'll talk in detail later erythropoietin okay that's interesting situation which cells in the kidney produce erythropoietin I think it's a difficult question or something oh my God he's telling I asked which cells in the kidney which cells in the kidney produce erythropoietin you say white blood cell in the kidney producers providing right you should get a big price for giving an answer which no one knows in the world yes it is wrong of course right I thought maybe some one of the video recorded as the right answer so in the kidney which group of okay this is difficult question you tell me in the kidney bit cell produce renin foreign okay that's good so renin is coming from there erythropoietin from where it is coming if any one of you can tell the right answer he can get at least 10 dollars for me which I don't have right now anyway foreign yes I think you become active if you are interested in ten dollars my question is which cells in the kidney produce erythropoietin yeah of course if we say kidneys producing Electro protein there must be some cells in the kidney where genes are activated making the messenger RNA the messenger RNA is translated then a protein is produced and that protein is called erythropoietin did you get it so which cell in the kidney yes yes if this is kidney and here is your Nephron you know in the nephron there's proximal convoluted tubule then there's Loop of Henley thin part thick part I will teach you detail later then this is distal convoluted tubule and collecting tubule from here the urine has go out these are proximal convolated tubules and here there are distal convolated tubules around them their capillaries which are called peritubular capillary Network capillaries around the tubes Parry perimen round Berry tubular capillary Network right for example one capability out of that Network I draw here this is a n disability is of course having what what are these cells I think these are endothelials right a special type of epithelial and Achieve yourself is that right now these endothelial cells if I make one endothelial cell out right these endothelial cells they are very very sensitive to oxygen levels they are having a special type of proteins and these proteins are called oxygen sensors what are these proteins called oxygen sensors within these cells so when blood is passing through this area oxygen goes into these cells and they activate the oxygen activate the oxygen sensing proteins oxygen activates the oxygen sensing proteins oxygen sensing proteins go and block certain genes this oxygen sensing protein will go into the go into nucleus transport into nucleus when they are having the oxygen they go into nucleus and inhibit the genes for erythropoietin production they inhibit the genes for erythropoietin production this blue Gene is erythropoietin producing Gene am I clear now what really happens when and your blood rbcs are less if they are reduced rbcs there is anemia isn't it then there is reduced oxygen supply and if there is reduced oxygen supply when there's anemia RBC mass is less total RPC mass in the body is less do you think you are carrying more oxygen in the blood or less if there's less oxygen reaching there then oxygen sensors are not getting the oxygen and if they are not getting the oxygen they cannot inhibit the erythropodin producing genes so erythropoietin producing genes are released from the inhibitory action of oxygen sensors and they they produce what they produce messenger RNA which will of course you know go to ribosomes and then that well they will make a new protein and this protein will fold and come out as erythropoietin are they throw point in this urethropoietin through the blood will go to the bone marrow house what is this bone marrow house the Sarasota protein will go into bone marrow house and there it will act on the cells which are responsible to produce rbcs which are responsible to produce rbcs so erythropoietin will go in the bone marrow it work on a precursors of a retired series the cells which will lead to formation of RBC is there in the presence of erythropoietin those cells start working more they survive more they live longer they proliferate more and they make more obvious you may be thinking words are fun to explain it at this moment the reason being there's a lot of clinical talk about it these days that if your kidneys fail both kidneys fail there are many problems in the body and both kidneys fail there are many problems in the body including this there is reduced erythropoietin production so patients who have chronic renal failure both kidneys not functional and destroyed by some disease norethropoietin reduced RBC production and patient develop swear anemia and these days how we are managing that anemia now we have you can say genetically engineered the formation of erythropoietin we have taken the gene of rethropoietin planted into geisten bacteria and those yeast and bacteria provide us genetically engineered arthropoietin and some these days if someone has chronic renal failure both kidneys are destroyed we give him injections of erythropoietin so that this should go to the bone marrow and increase the reciprocity activity am I clear sure so now you have to remember yeah how long does it take oh this is very important that if I give you injection of erythroprotein right now it will take about one week that is it will start raising the RBC level right it was a good question now erythroportion you know exactly from where it comes right it is from endothelial cells present in peritubular capillary Network renin come from juxta glomerular operators in some lectures previously I told you that here is the afferent arteriole here is glomerulus here is different arteriole this is our front article some cells in the afferent arteriole they are modified here and these cells are called they have these are the part of juxta glomerular operators because this this operators is made by modified vascular cells and modified renal nephron cells this group of renal nephron cells are called macula densa and this modified epithelial cells are called pulcation anyway but both together right both together modified vascular cells make this pulcation and modified nephron cells and distal convoluted tubule make put together they make a structure which is called juxta glomerular operators because the separatus is just along with the glomerulus and whenever this is stimulated it releases renin from here so source of raininess juxta glomerular operators right prostaglandin is produced by many cells okay is there any more function endocrine function of the kidney okay can we go to the metabolic functions of the carne we go to the metabolic functions of the kidney yes who is going to tell me some metabolic functions no that is the regulatory function if it is if kidney is dealing with the acid base balance that regulates the acid base balance we have discussed it already what is the metabolic function of the kidney number one number one it activates the precursor Vitamin D it converts the inductive vitamin D into active vitamin D is that right I will not go into detail at this level but still normally you know vitamin D let's suppose that's when sunlight falls on the skin right in the skin 7D skin produces a product which is called Kohli calciferol what is it called calcium you have heard of it this substance will go to the liver and when the substance come out of liver at its 25th position it has one added hydroxyl so we call it 25 hydroxy holy calcium feral but it is still inactive so when colic calcium flow passes through the hepatocyte it gets hydroxylated and its first hydroxylization is at 25th position but it is still inactive then it passes through the kidney you know and kidney passes through which cells there's some group of cell of course you will answer not me right when it passes through those cells they add one more hydroxylation first hydroxylene the hepatic hydroxylation is the divided position 25th carbon of the molecule then it passes through that it converts into one 25 single light oscillation double light oscillation now double die hydroxy Coley calciferol this is the really active form of vitamin D this is the active form of vitamin d is that right this is the active form of vitamin D right so kidney has a metabolic function to convert the inactive vitamin D into active form question is that which cells of the kidney do this function right you know every doctor may be knowing this their kidney is doing it but if you're really too good you must know which cells in the kidney are converting inactive vitamin D into active vitamin D by hydroxylizine by hydroxylation at Carbon number one because those cells have an enzyme which is called Alpha One hydroxylase enzyme what is the name of that enzyme Alpha One hydroxylase enzymes you may have heard of it somewhere in your past Alpha One hydroxylase enzyme though that enzyme is present in which cells of the kidney yes please anyone feel free to answer don't hide your knowledge you can answer as far as you are wrong yes no Paul question is supposed to produce renin yes any guesswork nothing Amal you are left Sharon that which cells in the kidney can convert inactive vitamin D into active vitamin D have you heard of something called proximal convoluted tubules those cells look at this cell you know after just this is the proximal convulated tubular cells these cells are having these cells are having Alpha One hydroxyl is enzyme so what are these cells these are the cells in proximal convolated tubule and vitamin D enter into that and then come out as double hydroxylated is that right so these cell problemated tubular cells these cells are very rich in Alpha One hydroxylase enzyme which is supposed to convert inductive vitamin D into active vitamin D how by converting 25 hydroxy colic calciferol into 125 dihydroxy calcified is that right did you want to know who stimulates this enzyme there is something which stimulates this enzyme and tells this enzyme please activate the vitamin D we need calcium in the body parathyroid hormone you know parathyroid hormone act on these cells and gives stimulatory signal for the alpha 1 hydroxylases so that more and more inactive vitamin D can be converted into active vitamin D but that will study in detail when we talk about endocrinology is it okay Alpha One hydroxylase enzyme is present in the renal cells which renal cells proximal convoluted tubular cells right this enzyme is present over there am I clear now what is the this enzyme is supposed to convert inactive vitamin D to active vitamin D but of course this enzyme should have some order something should stimulate it so that it started function so who stimulate this enzyme to convert more vitamin D into active form answer is parathyroid hormone because parathyroid hormone comes from the parathyroid gland parathyroid gland has Chief cells you know what parathyroid gland is Chief cell chi on the surface of Chief cell the calcium sensors on the surface of Chief cell the proteins which are called calcium sensors so when calcium bind there with the chief cell it inhibits the parathyroid hormone release but if in the blood calcium level become less ionized calcium become less then there is calcium sensors sense no calcium in the blood or less calcium in the blood they immediately Force the cell to release parathyroid hormone parathyroid hormone does lot of function one of the function is it will Rush towards the proximal convolated tubule and stimulate alpha 1 hydroxylase enzyme so that more more inactive vitamin D is converted into active vitamin D and when you have more active vitamin D active vitamin D will rise to the active vitamin D will rise to the git mucosa excellent and in the git mucosa it will help absorption of calcium now you see who sends the low level of calcium Chief cells but they release calcium manager who is calcium manager parathyroid hormone it does menu trick to bring the calcium level high one of one of the trick is it will activate Alpha One hydroxylase Alpha One hydroxylase will convert inactive vitamin D into more active vitamin D this active vitamin D Will D will go to the git mucosal cell and on those jit mucosal cell it will activate the genes it will activate the genetic Machinery of git mucosal vitamin D so that git mucosal cell make those proteins which will help in absorption of calcium so calcium lowering effect was sensed by and calcium is getting after multiple signaling mechanism in the body from JT waves are more calcium but parathyroid hormone does many other functions which we'll discuss again in this lecture of renal physiology we will specially concentrate and learn their relationship relationship between cardiac output relationship between cardiac output with the renal blood flow adrenal blood flow and what is the relationship between the renal blood flow and renal plasma flow right and what is the relationship between the renal plasma flow and Pulmonary filtration rate right and how will normal filtration rate is translated into tubular flow that fluid is flowing through the nephron tube and in the end how it convert into urine output hear it output again this is very important physiological concept that a good medical student should know what is the relationship between the cardiac output and renal blood flow and what is the relationship between the renal blood flow and the renal plasma flow and what is the relationship between the renal plasma flow and Global filtration and what is the relationship between the GFR and tubular flow and eventually how the tubular flow flow in the end translates into urine output it means cardiac output is started with the cardiac output will end up into you're an output but before we really go into detail of this system I would like to clear some concepts related with the renal vasculature because during formation formation is a very important interplay between the renal blood flow and the nephron function let me repeat it urine formation by the kidney is Right determined by the very close interplay between the renal blood flow system and renal nephron system so first of all I will explain that the basic concepts related with the renal vasculature then I will explain a little bit about the nephrons and then I will develop the relationship between the renal blood flow and the nephrons after that I will explain these things right so let's go to the very very basic anatomy and physiology which is required to understand these things right let's suppose that here I make kidney all of you know that this deeper part of the kidney this is medulla right I've made it three middle areas of course there are more right but Allah and outer part is yes please what is it this is cortex this is renal cortex this deeper part is original medulla and here we can say okay I'll make the calluses more clearly these are the glacial system right and here is renal medullary system is that clear now already you know that this is real cortex this is original medulla there is urinary collecting system but we have to develop the relationship between the renal vasculature and the how the nephrons are fitting into this picture so let's start with the original vasculature uh this is aorta you know from the aorta the renal artery is coming and renal artery of course abdominal aorta it will divide into posterior Division and interior division this will divide into posterior Division and anterior division will be of course going to the posterior side of the kidney and nutrient is coming interiorly this is the interior Division and here is the most shared vein and this is the main renal artery here is maintenance artery dividing into posterior Division and interior division then from these divisions branches will go to Every Loop for example this is one and enter lower branches this is going to another lobe here is an artery which is going to another lobe so and so fourth so what are these branches coming from here these are inter lower branches right these are inter lower branches right now let's suppose an interluber branches reached at the junction of Cortex and middle law they divide into these branches which are arcing over medulla and cortex Junction this arcing branches are called arcuate branches in the same way this will also lead to what is this Branch please or create this is going to Arcade here it has gone to arcade and this will also go to Arcade arteries what are these which branches please our weight branches you can repeat it with me no problem so again listen carefully this was the main renal artery right number one number two you go for deviance number three you go for enter what is this low bar l o b r interluber branches no problem to here then they divide into this fourth number what is this yes branches right now what really happens from the arcade branches from here there are branches which are straight going into deeper part of what is this cortex and these branches are called interlobular branches what are these enter lobular branches like this and they are of course present throughout what are these branches please enter lobular branches right so and so forth so they are present throughout but I will not make throughout do they have to explain a few more facts so this was arcade artery and this was earthquate artery and from here enter the viewer branches now let's suppose we concentrate on one interlobular branch this is one enter lobular branch what this branch is doing you know from it these are small arteries which are going on the side what are these arteries yes a bus you can tell me what are these arteries they're going on the side they're offshooting from the enter lobular right yeah what are these called afferent arterioles these small branches are afferent arteries actually these effluent arterioles are supposed to bring the blood to glomeruli is that right now these effort arterioles will break down into capillary Network right they will break down into capillary Network right and this triple the network which is made over here what is this called glomerulus what is it called glomerulus what is glomerulus is a capillary Network which is produced by the breakdown of the effort arterioles into critical a network am I clear now here is your okay I will just remove this collecting system to reduce the complexity of the picture but don't forget kidney is really complex but very very interesting to learn now from this nephron globalize this is now I'm trying to develop the relationship between the vascular system and nephron system this is the beginning of the renal nephron you know Bowman's space right the bunch of capabilities of glomeruli are enveloped whether Bowman space and then this part of the Nephron they break down into plausible convolated tubules you know it and then from the possible convolution tubules for example this is plausible converted tubule of course it's in the cortex from here this is going down into medulla and this is called Loop of yes please handling and then it develops a thin turn here and then it develops thick part of loop of Henley and thick part of loop of Henry turning from medulla to the cortex right and then this will divide into what is this distal convoluted tubule and distal convolated tubule again turn into middle law as collecting system collect particle Collective tubules and then metal recollecting tubule then eventually collecting duct and from this point what will come out what is it drop off insurance is that clear now what we have seen here that we have seen that this is possible convoluted tubule Bowman capsule proximal can related tubule Loop of Henry what was this distal convolated tubule and distal convolated tube will eventually break converted to Vertical connecting tubule this is collecting tubule and then eventually this is going to the middle law is that right now this culmarath is in the cortex but some globularly are very very near to the Junction of Cortex and medulla for example if glomerulus is formed here suppose it is a glomerulus here this is more near to where to medulla such glomerular are called juxta medullary globalized such glomer layer called this one type are called are cortical pulmonary and about 10 to 15 percentage their slight anatomical and functional differences which I will explain right first we concentrate on this vertical globalist how it works now what you have learned yes what was this artery come in this place what was this artery coming our front this was a front artery this artery breakdown to rays which is called vegetable is and within this capillary Network there is some connective tissue and cells what are these connective facial cells what are these connective facial cells there's some these capillaries look this is a front arterial it breaks down into capability Network this is different artery this is different and here it was what was it our front through the front blood was coming and through the effort blood is leaving the global eye suppose here in the diagram I've shown two Loops of people lays one Loop of capillary is this one another loop of criminal is that one am I clear actually normally one efferent arterial make 10 to 15 loops or bunch of Apple a networks right now here is what is this moment space is that right of course you know this is also made of cells we'll talk in detail about that later right I was asking that this triple re bag this is embedded into some special type of connective tissue you see it this blue connective tissue I want to know measures should be very very clear about this connective tissue through which the capillaries are looping your understanding exactly what is the position of this connectivity look here if my fingers if my fingers let's focus on this if my fingers are the loop of capillaries right this Loop of triple is applied on one side of Bowman capsule but in between the people is there is some connective tissue and here is also some connective tissue what is this connective tissue called you have heard of it I'm very sure you are even for USMLE Stefan even you are supposed to know the diseases of messenger this is called messenger have you heard of messenger's health or casual hear in your life especially when you sit down for some good medical education these are called messenger's health and messenger is that right now what really happens look it's a very unique type of capillary Network this is a very unique type of capability Network normally in most of the places in the body so polarities on one side of Articles other side they have wind but this is unique that on one side it has arterial another side it has also arterial so it means this network of capability is present between two arterios not between one article and next brain when you you know we knew the very low pressure system but arterials are very high pressure so uh because this articles remain constructed so pressure in the glomerular system will be low or high it will be high the pressure as compared to other capillaries in the body because and most of the time okay let me tell you a simple example in most of the places in the body this is the artery and here are the people rays and then this artery will break down into what when this is a very low pressure system so it's a high pressure blood is coming with high pressure it falls into the pellets and drains into low pressure system so pressure within the most of the capability is very low but if you put an arterial here as well as you put an arterial here then pressure in this area will be very very high this is a unique thing about the capabilities of the gloomerular that this triple network is you can say having arterial in the beginning efferent arterial and even they come the blood to the scripturally network is coming from article and even draining into arteries so it's a very high pressure catalyze system and this high pressure help in higher rate of filtration the fluid will filter from this capillary area to where to the urinary space fluid will filter into urinary space we'll talk about that later in detail of course right now this is a front arterial let me make it here that this is now what is it infinite article now where the blood from effort arterial will go now we have to see keep it focused where the blood from ethernet arterial will go any one from you no idea look it goes along that is very true but we are right look it will again break down into capillaries it will again break down into and now this crippled race will be draining into true veins which will take the blood back are you understanding now so it means look here that afferent arterial lead to one first group of people is break and take the blood into effect arterial which break down into second group of fibulus then blood from the second group of people is really ran into venous system of the record name it means first coupled network is a high pressure system and second capillary network will be low pressure system so let me make it here on this diagram this is what is this this is proximal convoluted tubular and this is Luba family this well different arterial will break down into capillaries and these people Rays right actually if you truly see them Gene scriptures move around this possible convoluted tubule now what is the purpose of these people is let me tell you these crippled is this Tripoli Network called peritubular capillary Network there were two people in network one here this is glomerular capillary Network and this is Parry tubular capillary Network very tubular capillary Network Harry tubular capability network is an enveloping it is surrounding the proximal correlative tubule as well as digital converted tubule in the renal cortex let me show you here truly speaking this network of people is it is like this right you are understanding I have just made it a easy diagram but actually they just break it into a couple days which go around the possible cumulative tubule as well as distal convolated tubules am I clear now and then what is the major function you know plausible and distal convoluted tubules are playing the major role specially plausible into lot of reabsorption and secretion so a lot of substances which are filtered they are reabsorbed from this area back to the blood lot of substances which are filtered like all the glucose which is filtered within physiological limits that is reabsorbed to carry tubular capability Network or all the amino acids which are filtered they are reabsorbed and many more substances we'll discuss later am I clear right and then of course these veins will go back into interlobular veins and arcade veins and interlobal vein then between the vein and then into reign of vein and of course not into your time too not into aorta into inferior Finance is that clear there's no need to remember that thing but basic stuff a vascular system is clear to you fine so we can say that cortical structures listen carefully cortical structures of the Nephron are provided by the by two capability networks number one is peritibular Triple A network is that clear now a little complex thing coming I will explain it to you let's suppose what is this this is your yes what was this please tell me these are these were these are the front arterials what are these affluent arterials these are capillary capillaries and these are different is that right now and now this infinite is in the cortex this infinite is also in the cortex this is also in the cortex this infinite is very near to the medulla these three kilometer lie will be called cortical but this converter which is very near to the middle line is called juxta this lumorless right which is very very near to the what right it has a different relationship s it has a very short probability tubule very long what was this Loop of family and then it has very short distance relative tubular and collecting system is that right Amic layer Amal that this was cortical Global lie what is this juxta now the real difference is in their effort arterial you know that these different arteries will break down into what type of is very tubular what they break down into what very tubular capillary networks but this will not break on to peritubular this will make people raise which will not go around that these typically Loops will go down into where where they are going into medalla are you understanding nothing that different arterioles from cortical Global lie they break down to peritubular capabilities but different artery over from the juxta metal regulary they break down into Loop of capillary as we go deep down into vidala and then from madala they return back into cortex this long Loop of is is called Visa Vasa recta because these are straight vessels they call them have you heard of vasarata good so these are called Vasa recta actually was a rectal later on I will tell you they're playing a specialized function and maintaining blood flow very little blood flow in the renal medulla they are maintaining a very little blood from the arena in a renal medulla right so now and of course when this Visa Rector turned back they also drain into veins and these veins will take the blood back I will not go into detail of this Venus pathway you can understand and Visa recta will come back they will go into veins our great veins then into enter lower veins and then into divinal veins and you know it eventually an end in fear winner is that right the point which I wanted to highlight I will again highlight there because it's worth repeating right now you people will tell me how it goes I'll draw another kidney and now this is your test that have you understood this concept or not I think someone has kept over here okay listen here is medulla I will make it like this this inner area is cortex and here what is this is that right now listen carefully these are the I will make only one example this was arcade artery isn't it interluber artery or quite artery and what is this enter lobular and from the interlovular what is it afferent and this effect is going into which uh particle or juxtamentally cortical and I make another here so that you really understand okay what is this this will make our life what is this what is this particle this is cortical regardless Bowman capsule what is this possible correlative tubule is that right right and from this proximal convulated tubule proximal convolated tubule these are Loop of only and it is turning it's back then into which distal convolated tubule and in the end collecting system is it clear now this will break down into what kind of Ripple is what are these capillars tubular is that right and then returning back to the venous system is it clear no problem after this yes please this is a front article this is different this is interlobular this is our weight you know interlow bar arcade interlovular afferent pulmonary capillary tubular capillary Network venous drainage hello I think okay now the difference is what was this one it was which one the summary now just terminally it has a woman capsule and it has also what is this is it clear look and its vascular system and its remaining nephron it is juxta medullary now the beauty which you have to appreciate is that this effect in the cortical was breaking down to which cable is very tubular and this will break down into which cable is Visa so they will straight go down and like this and they will call back and they will also go for the now from here Venus return is that right so this is with a recta about 90 percent of blood flow is through the cortical system and about 10 to 15 blood flow is through what is this just no 90 to 85 to 90 percent of glomerular cortical about 10 to 15 percent gulmarlaya about very most of the blood flow is through the cortical system and through the Visa recta there's very little blood flow teach you that in the middle of there is hyperosmolality there are lot of solutes concentrated into medalla I will explain later there's a lot of solutes Welcome with lot of solutes are concentrated into medulla it's very high concentration of solutes right now we say there is medullary interest interstitial medullary interstitial hyperosmolality later on I will tell you what is the purpose of this but this hyperosmolality is created with use a lot of energy and it helps and concentration of visual Azure and right now because we have concentrated lot of solutes into medulla body does not want that these Solutions should be washed away should they be washed away no now if we don't want them to washed away then blood flow should be slow or fast slow if you have some mud here water flow is very fast it will wash away water is going little back it will not wash away so in the same way Visa actor has very little blood flow so that medullary interstitial hyperosmolar setup should not be washed away that's the right that I will teach later how this hyperosmolality is formed and what is the purpose of having this area hyper smaller is that right any question up to this there's no question okay let's suppose that here is your circulatory system let's see here circular tree system right and here is your beautiful heart pumping the blood all your life right now what is the normal cardiac output what is a normal cardiacard how my blood is pumped by the left ventricle into arterial tree systemic arterial tree permanent what is the amount of blood pumped by the left ventricle into aorta and eventually into systemic arterial tree that is you know cardiac output is equal to what is equal to heart rate into stroke volume that what is the volume pumped by the left ventricular per stroke and how many strokes per minute so you know that is 70 2 into 70 heart rate is on average 72 beats per minute and 70 ml is the blood which is ejected by The ventricle healthy ventricle and resting conditions so become about five thousand and the L right but per minute so it is about five letters blood per minute resting healthy person approximately so now you are studying the lecture I hope you are somewhat resting uh at least physically so what is happening that five liter of the blood is formed by your heart into your circulatory system every minute now out of this five letter right this is the five liter blood is that right this is five later black and this five liter blood out of this how much blood goes to the renal system about 20 to 25 percent suppose 20 percent to the renal system let's suppose twenty percent blood is going into renal art arterial tree right renal arterial tree there's 20 blood going 20 blood makes how how much out of five letter if I say 20 blood has gone to the renal blood flow how much it make one letter is that right it makes one letter that means that out of five letter every minute your both kidneys are receiving one letter of the blood and of course there is no fun in explaining that one liter blood is equivalent to how many mls one thousand MLS per minute out of this Blood which is going to the kidney 1000 ml this blood can be divided easily into yes cells and what is the other thing plasma is that right you know about 40 percent of the blood is cells so white blood cells red blood cells and platelets they make about how much 400 and the cells are about 400 ml out of the one letter which is passing through the headings Force this is a gorillas right so naturally what is this now 400 ml cells are passing through the all glomerular you know how many glomer layer there and both kidneys together they're about 2.5 million I'm just showing one but the values represent all the gulmarula put together right and how much is the plasma now how much plasma is there yes if 400 ml has gone cells plasma is 600 ml so it means true or glomerular structures every minute there is 600 mL of the plasma flowing through because health will flow simply they do not filter rbc's wbcs are greatly adds they simply pass through the global lie next to the different arterial right cells remain same 400 ml South but in the plasma the 600 mL of the plasma as it is passing through glomeruli a part of this is filtered into where structure this is your blue marvelous and this is which tubule proximal convolated tubule and you know that this proximal convolated tube will go into Loop of Hanley and this Loop of Henley will turn up ascending limb this was descending Loop of Looper family here pin turn ascending Loop of loop of Henry thin part and thick part of ascending limb of loop of family and here it is distal convoluted tubio and what is it here collecting system and drop off urine coming out eventually so let's develop the connection I said that heart is pumping how much blood per minute five liter out of that 20 is going to the kidneys it means renal blood flow is 20 percent of the cardiac output or 20 to 25 percent of the cardiac output that is approximately one liter or 1000 ml blood coming to the headness out of that approximately 400 mLs are the cells and plasma is 600 ML and plasma is 600 plasma is 600 mL out of this 600 mL plasma you know cells don't filter they pass forward but even plasma is passing through this area right fluid of plasma with the dissolved substances is filtered out of the plasma proteins don't filter significantly proteins don't filter it is the fluid of the plasma with some dissolved substances that can filter but how much out of 600 how much filtered total it is again 20 percent this is twenty percent now you have to remember out of total cardiac output how much is coming to the kidney 20 and out of total plasma flow how much is filtered 20 now out of 600 mL 10 is 60 ml and 20 is 120 ml so every minute approximately 120 ml fluid is filtered in every n n all the government spaces together is that right let's suppose for practical purposes we say it is 100 ml this is 100 ml just to make it easier calculation just place it's both kidneys combined and all nephrons combined right the whole Global filtrate total glomerular filtrate in your body every minute is about 120 ml of course it is 60 ml per kidney right now we will see that this 120 ml as it is flowing within the Lumen what happens to it and how much appears in the end as urine is that right that this 120 ml when it is passing through the what is this Nephron in the end how much comes out as urine drop what do you think out of 120 ml normally how much come out as urine drop one ml okay what do you think one hammer how look about 65 percent of right again let's suppose for practical purposes we make it 100 ml if it is 100 ml which is filled entering into tubule about 65 percent will be reabsorbed in proximal convolution lot of solutes with 65 percent will be reabsorbed into proximal convolated tubule and remaining is moving forward out of this as it is moving forward how much is reabsorbed here 10 to 15 okay make it about 15 of course there is a range but for easier remembering out of 100 ml 65 ml is reabsorbed in proximal calculator table 15 MLS reabsorbed through the descending Loop of loop of Henley and then how much is absorbed from the sending limb of loop of only answer is that ascending Loop of loop of family is water tight under all physiological circumstances so nothing is reabsorbed from here you can make a diagram like this even if they try water will not be from here so it has to move forward is that right it will not be reabsorbed from proximal sorry thick part of ascending limb of loop of Henley then the tubular fluid will reach to the distal convolated tubule now you have to understand it we had originally 100 ml here and 65 was absorbed here what was entering here 35 mm is that right out of that 35 ml how much is ribs out here yes 15 so how much it become 80 ML and what is left forward reabsorption is 65 plus 15 about 80 ml is reabsorbed how much is moving forward about 20 mm is that right out of this 20 ml which is here in this part about 15 mL is reabsorbed so how much is reaching now forward only 5 ml per minute so this is a 5 ml of the tubular fluid which is provided for a minute to the last part of the Nephron and this is the function of the last part of the Nephron to fine tune this volume that how much should be reabsorbed and how much should be allowed to go into urine is that right normally what really happens as this 5 ml fluid is going down under the influence of altosterone to one to two ml or 2 ml or 3 ml is reabsorbed and a little amount is also reabsorbed under the surface of ADH this last three absorption is under the reference of aldosterone Elder on which reabsorbs salt and water and expels the secrets of potassium and ADH which the help of idiot you reabsorb the water mainly and usually in a healthy person how much appears in the urine drop is just one ml how much is appearing into urine this is one ml right so this was your drop-off urine and here was your lectin Dot right this is one ml per per minute so normally one cc or 1 ml urine is produced by both kidneys together about every minute is that right now it means out of 100 ml which was filtered about 99 percent of the fluid is reabsorbed and only one ml is usually going out as urine from this we can calculate if every minute one ml blood is A 1 ml urine is formed then how much urine is formed per day it depends on how many minutes are there in one minute one day in 24 hour how many minutes are there Nazarene has calculated I think you never had time to go 3 600 minutes per day I think your day was too long you are missing someone let's calculate truly lesson one day look one hour has how many minutes let's calculate it we don't need arshamitas for these calculations this is a very simple you know one hour is 60 yes don't tell me 60 ml 60 minutes right and usually in one day how many hours sure 24 hour so in one day how many minutes this is 60 into 24 is equal to 1440. pour it in 40 minutes per day if you don't believe it one day you can spend and calculate it right now listen every day we have 14 40 minutes and if you're producing every minute how much you run one ml so how many angle during you produce per day on average yes about 1440 ml approximately one and a half later so normal person produces urine output approximately one and a half later but normal range of urine output is that normal range of urine output is the minimum is allowed 500 ml and maximum is allowed 3000 500 mL you should produce urine this is the normal urine output per day right that normally you should produce urine more than 500 mL and usually less than three thousand five hundred ml it means that 24 hour unit output should be more more than half liter and less than three and a half later I will tell you why right yeah just a minute before you tell me something new I will tell you why we why during lesson this is bad and why is urine more than this is also bad is that clear but look at one thing that by producing 1 ml daily you produce one and a half liter if you produce one ml every minute then it means daily you produce one and a half later and if you produce 5 ml per minute you will produce seven and a half later or if you just rather than 5 ml five ml is going down all of it goes down here in output will be seven and a half later or only 4.5 ml is reabsorbed only half ml goes down here in output will be about 700 mL so this is the fine tuning in the last part of the Nephron that last part of the Nephron is working on about 5 ml of the fluid to adjust what should be the urine output but normally urine output should be maintained somewhere between half liter to three and a half letter right if Uranus less than 500 mL we say there is oligoduria and if there's urine is more than three and a half liter we say there is holy urea less than 500 ml is that right now before we really close this area we must know that why it is so important that doctors say that if urine output is more than three and a half liter it should be called police urea not normal and we should also have a very clear concept why when unit output is less than 500 mL it is a pathological condition I will explain all right first I will explain why our normal healthy person should not produce urine more than three and a half liter under normal circumstances of course if you drink lot of water you will produce more urine right now we will talk about that we have already discussed if you're an output is less than half liter or less than 500 ml per day you see patient has only go urea and if you're an output is more than three and a half liter per day do we call it there is poly urea we have to think that why for oligo urea the cutoff point is around 500 ml and why for police video we put a cutoff Point around 3500 ml first we'll deal with 3500 ml listen first of all you should be thankful to the nature that it has provided to the urinary bladder because that act as a storage place when urine is coming and then you can release or evacuate your bladder as you feel comfortable socially and otherwise clear now what really happens for 24 hours more than three and a half later then during eight hours of sleep so much urine accumulate into bladder that it becomes very discomforting and you have to wake up and pass urine so it produces nocturia and quality of life is Disturbed so doctor thought that in a normal person if he empties his empties his bladder before sleeping then he should have a sound sleep and whatever urine he produce around eight hours that should be accommodated into normal bladder well but whenever your unit output become more than three and a half liter unit flow is so fast that during sleep you have to wake up once or twice or even Thrice depending upon the degree of college area due to this reason they say the normal urine output should be less than three and a half liter because more than that will produce nocturia and struggles with the Sleep Quality and life quality is that right you got the answer to this why now the question is this why urologists and nephrologists are very concerned that their patient should produce urine output at least uranophilia yes urologists and nephrologists they're very very sensitive to the patients and actually every good doctor is sensitive to the patients urine outward that it should be at least 500 mL because if urine output become less than that that may become problematic for the patient let me explain to you you know normally listen carefully normally uh what is the concentrating ability of the Azure kidney to concentrate the solute for example when metabolic waste meta bollock waste product which are daily produced metabolic waste products luxuria creatinine their potassium and many other substances these metabolic waste which are daily produced right normally what happened that kidney has to concentrate them all the metabolic waste which are present in our body they should go out through kidney and of course kidney has to concentrate and dissolve these metabolic waste into fluid metabolic waste are not coming out out as tablet form or as powder form they are coming as dissolved form into urine is that right now so kidney has the capacity to concentrate these metabolic weights waste into volume of the water normally the maximum capacity of a healthy kidney is around that healthy kidney can concentrate 1200 Millie or small a mini mold of metabolic waste in one liter of n1000 mL of water is that clear if kidney death is best for example it is water deprivation if in body has water deprivation kidney will try to produce less urine but maximum then of course kidney has to concentrate the metabolic waste into minimum volume but kidney try to concentrate the metabolic waste and milios right into water the normal highest capacity for concentration of the kidney is around 1200 or 1400 millimoles of metabolic waste and one liter of urine is that right now listen carefully in normal person how many how much metabolic waste are produced per day in a normal person with a 70 kg weight on the normal physical activity and on average diet normal diet right such person normally produces daily about 600 millimoles of metabolic metabolic waste in a normal person metabolic waste are per day daily so daily how much you are producing metabolic waste around 600 units 600 urine units now 600 units of metabolic waste you produce daily now kidney can concentrate 1200 units of waste in one liter so to get rid of 600 units of metabolic waste kidney should need how much water 500 MMA that's it 500 mL of water so it means that if your urine output is dropping still if kidney try to concentrate all the metabolic wasted minimum volume it really need at least 500 kidney needs at least 500 mL of the water to dissolve the daily waste products is that right now you imagine if urine output is about two and a half to the 200 and 50 ml right if or your kidney urine output is only the water available into urine is only 200 mL can kidney concentrate all the waste into 200 mL no so what will happen metabolic waste will start accumulating in your body metabolic waste will start accumulating in your body and biochemically in your blood blood chemistry will be altered for example urea and creatinine level will start accumulating into building up into land that is why good nephrologists and urologists are very concerned that normal Health person should produce at least 500 mL of the urine so that his metabolic waste should be properly concentrated and cleared out of the body if person is producing only 200 or 300 mL of the urine then some of the metabolic waste will be retained in the body and blood chemistry will be altered due to impaired renal function or reduced renal function am I clear is it are you clear now tomorrow if someone asks you then why we have to produce at least 500 mL of urine you know the answer because in less than that doctors get upset they get worried how to improve the urine output anything you remember from here you can infer that those patients who have severe catabolism in their body breakdown in their body for example a patient with severe trauma patient with severe extensive surgery patient with the burns patient under accidental breakdown of the tissues such patients have lot of proteins breaking down in their body so do you think if proteins are breaking down into amino acids then they have been producing more urea so such patients which are having hyper catabolic State they are having more solute more metabolic waste or less metabolic equations the more metabolecules who are the patient who are suffering with Hyper catabolism Burns patient High traumatized patient you can say extensive surgery extensive trauma or severe sepsis patient septicemia they are undergoing very rapid catabolism is that right so any condition or forget about even a healthy person who takes lot of you know chicken and lots of mutton so you support stuffing lot of proteins in his body and amino acid so amino acid breakdown will produce more urea and other products so all those conditions in weight you produce lot of catabolism in the body of the proteins in these hyper catabolic States even a very good doctor only the very good doctor will be upset even when patient is producing 500 MMR he knows that okay that normally a person should produce 500 mL but my patient is under hyper catabolism he should produce at least 1000 ml and he will get upset whenever this unit output goes even less than so it is not something like a return in Bible or some other thing the important thing is that this thing is you have to think with your mind it's not fixed that in a healthy person you need 500 mL at least but a person but in a person who is under hyper catabolism and who is producing excessive metabolic waste you need to run the urine output more than 500 ml per 24 is that clear to everyone right another thing which I would love to tell you that let's suppose this is your circulatory system and here are your beautiful kidneys only very few people know how kidneys are beautiful but anyway I think kidneys are not properly respected and regarded you know heart is given unduly more attention if kidneys are not there you cannot live we want to love anyone or to receive the love of anyone yes but they are underestimated you know like many people Now look for example if kidney function is impaired right and urine output is total unit output is less than 500 mm or 24 hour that is Olivia what will happen that waste product will start metabolic waste will accumulate so urea and creatinine level will go up maybe potassium and many other waste products now look when kidneys start failing this waste products start accumulating in the blood when these waste products are initially accumulating into blood blood chemistry is altered but still there may not be any signs and symptoms of heart disease when only blood chemistry is altered and yet there are no signs and symptoms we call patient is suffering with azotemia is a Timmy have you heard of this term isotemia what is the isotamia isotemia the clinical pathological condition resulting due to renal dysfunction in which blood chemistry is altered right due to impaired renal function like zuria creatinine elevated maybe acid base balance or electrolyte balances Disturbed but everything is mild and yet there is no symptoms of signs of a renal failure but when with the exotemia when it is a demia plus there are signs and symptoms of renal failure the condition is called yes renal insufficiency is already there what is this condition called you have heard of it when someone has azotemia developing pericardial rub nausea vomitings solar skin other features of renal failure what is that called what is this called it will say yes now patient has developed uremia have you heard of uremia uremia is not urine in blood uremia is a clinical pathological condition characterized by severe disturbance in renal function which is not only having the acetamia plus also signs and symptoms related with the linear failure right for example patient may develop nausea vomiting or with that pericarditis or skin color alterations acid-base disturbances leading to hyperventilation and many other clinical features right then we see patient is suffering with uremia do you have any question up to this there's no question

Channel: Dr. Najeeb Lectures

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Keywords: medical lecture, drnajeeb, drnajeeblectures, functions of kidneys, kidney, function of kidney, structure and function of kidney, physiology of kidney, kidney disease dr najeeb, kidney failure, nephron function, nephron physiology, nephron structure and function, renal pelvis, urinary bladder, glomerular filtration rate, gfr, glomerular filtration, usmle, urine production, kidney function, medical lecture on kidneys, kidneys function lectures, dr najeeb lectures, dr najeeb

Id: oBoEYdWhtpM

Length: 121min 47sec (7307 seconds)

Published: Sun Nov 06 2022