hey and welcome back to fluid and electrolyte balance and so let's just go there right now all right so oops sorry about that all right so here is where we left off last time is starting with the regulation of fluid balance so how are we going to regulate our fluid balance we are going to do it through oh let me get my PIN okay so we're going to monitor our blood volume make sure that we have the right amount of volume so how one way that we can measure our blood volume is by measuring our blood pressure and then the last way of course is to check our plasma osmolarity if it's too um too concentrated then we're going to get rid we're going to add some water and if it's not concentrated enough we're going to get rid of some water so um this is the major way too so sorry I'm making plastic wrinkly sounds this is the main way that we regulate flu bones is by monitoring blood plasma osmolarity so in the case of fluid intake is less than output we're going to get a decrease in pressure and a decrease in volume but we're going to get more osmolarity if more water is lost in solutes and that's typically what's going to happen we rarely have a situation where we lose isotonic fluid because when you think about what were the causes Hemorrhage diarrhea those kinds of things no we're more in a dehydration where we lose water and we're and of course and we're losing water then we get a bigger percent of solutes and therefore the osmolarity will go up then a flu intake is greater than output increased blood pressure volume and decreased osmolarity again overtonic overtonic hypotonic hydration or over or drinking too much water will cause that to happen so how do we do that well um we're either so think about you're in a positive water balance which means you have too much water or you're in a negative water balance which means you don't have enough so are you going to want to drink or not want to drink so we're going to check our thirst Center so we're going to check on the activation of our thirst Center and see do we want to take a drink or do we really not want to take a drink so what kinds of things are oh and this is going to be in the hypothalamus so you um let's see I'm going to do a little thing I was just reading the next slide to see if that's what I want to do but no I'm going to do it after I read through this slide and then show you something um yeah just a sec oh it's right here sorry all right decrease blood volume decrease blood pressure so we're going to measure um our bear receptors are going to detect so let's put their receptors oops will detect a decrease in blood pressure all right now if you remember back from blood pressure what does that gonna do what what stimuli do I need in order to raise my blood pressure where I'm going to increase output oh sorry increase output from my cardio acceleratory Center and I'm going to vasoconstrict okay well what causes that sympathetic stimulation all right so five sympathetic stimulation going on hey remember sympathetic stimulation goes to the JG cells or the granular cells of the kidney and cause the release of Remnant and so then when renin is released then you will produce Angiotensin II and Angiotensin II will in turn stimulate The Thirst Center so that's one of those five functions of the of Angiotensin II all right now this next one increased blood osmolarity is usually well it's the strongest one let's put it that way uh and so here's how it works so if I don't have enough water intake we're going to stimulate sensory receptors in The Thirst Center directly now I love how this works so you are going to have a group of cells little inner neurons here in your hypothalamus okay so here they are so these are our plasma osmo receptors I shouldn't have written that right there but oh well okay so now here is the capillary going by and that capillary does not have enough water so I've increased blood osmolarity well what's that going to do so if I am if I've increased blood osmolarity I am hypertonic hyper T so now what's what's going to happen water is going to leave here and water is going to leave these cells these plasma osmo receptors so now what are they going to do they're going to start to crenate and as they crenate now they are sending signals to the paraventricular nucleus and the superoptic nucleus in the hypothalamus hypothalamus cells that are now running down here to release ADH from the posterior pituitary oh look it we just came full circle from the very beginning of the semester remember we said hey what about that neural hypothesis neural hypothesis thing that posterior pituitary does it make us own hormones no it doesn't it just stores ADH and oxytocin made in the hypothalamus so what would be the stimulus to release the ADH that is just sitting in the posterior pituitary waiting well it's when the plasma osmo receptors in the hypothalamus crenate as they're losing water to the hypertonic environment of the capillary and now that causes the um superoptic nuclei so p-o-n and the pvn paraventricular nuclei those cells to read to release ADH so there is stimulates the hypothalamus trigger to trigger release of ADH I love that so much that's one of my favorite things that goes on in your body okay then decrease cellular secretion sensory input relayed from receptors and mucous membranes that's also known as dry mouth so yeah there are sensory receptors in your mouth that when they are dry they send the signal directly to the hypothalamus you want to take a drink of water you know what it feels like when you have a dry mouth and you're just like oh I'm spitting cotton balls I need to take a drink of water that is a very powerful stimulus is having that dry mouth I'm getting it right now and I I'm not going to drink but you know how that works okay so those are going to be things that are going to activate right there activate The Thirst Center okay what about inhibiting The Thirst Center well obviously if we have more fluid intake our blood volume and our pressure is going to go up and so our we're not we have uh High BP so that's when our um baroreceptors send more signals to the um to the high or to the medulla to tell the medulla let's stop sympathetic stimulation let's kick in some parasympathetic and let's calm everything back down again so if you have no sympathetic stimulation you will not release renin and if you don't release renin you're not going to release Angiotensin II and we're not going to stimulate the third Center anymore now if your blood osmolarity drops okay then you decrease the stimulation of ADH so we have no stimulation of the plasma osmoreceptors no crenation no crenation okay osmo receptors all right now when your mouth is not dry you don't send a signal to your brain anymore makes sense and distension of your stomach you stretch your stomach you're going to inhibit the third center of the hypothalamus okay those baroreceptors in the stomach all right so there is what happens if you want to inhibit The Thirst Center all right so um the hormones that are going to be and we'll be looking at this later um or hormones involved in regulating urine output Angiotensin II antidiuretic hormone and aldosterone these will all decrease urine output to increase blood volume and blood pressure we should remember from when we did the urinary system in long-term blood pressure regulation that Angiotensin II was produced by the kidney and this is what's going to meant to regulate your day-to-day blood pressure and so by regulating your blood volume by increasing your blood volume so Angiotensin II ADH and aldosterone all three of those will increase your blood volume but if your blood pressure is too high if you've got too much water and you need to increase your water output then ANP is going to do that because your A and P in your heart is going to get stretched well the heart Atria are going to get stretched and then that's going to cause the cells to produce A and P and then they will cause you to get rid of sodium and get rid of water so increases urine output to decrease blood volume and pressure all right so now we need to go into the electrolytes so um we have non-electrolytes and electrolytes so non-electrolytes are molecules that do not dissociate in solution so they don't form ions most covalently bonded organic molecules glucose um amino acids vitamins okay not minerals because our minerals are primarily our electrolytes now when they get into our body so they're going to come in like this okay like sodium chloride or potassium chloride so those are going to come into our body and as soon as they hit water then they dissociate into their ions so then you have a sodium ion you have the chloride ion so those are electrolytes and why do we call them electrolytes because they can conduct an electrical current when dissolved in water and this is why friends that water conducts electricity water if you had deionized water it wouldn't conduct electricity but how often do we take a bath and deionized water or swim in a lake that's deionized so we don't have to worry about being electrocuted if something electrical fell into the water or got struck by lightning or something like that it's because of all the stuff that's dissolved within it and a vast majority of the stuff that's dissolved within the water will dissociate to form cation cations and anions and those will conduct the electrical current remember sodium and potassium are what is absolutely necessary for membrane potential which is simply an electrical current along the cell membrane okay all right and then each unique function in osmo and osmotic functions and we write it in Mill equivalents per liter or the um electrical charges in one liter solution so just know I know you probably haven't seen a a unit of Mill equivalents per liter before but that's how we measure our electrolyte levels all right the first one we want to take a look at is sodium and so sodium is look at that 99 in your extracellular fluid so your blood and interstitial fluid and one percent your ICF obviously because sodium is the major cation extracellular cation that we use for membrane potential so it's got to be on the outside and we maintain that gradient we have 99 to 1 by the sodium potassium pump Oh I thought I fixed that that is the principal cation in the extracellular fluid sorry about that and exerts the greatest osmotic pressure and we already know that because what do we always say water always follows salt but the sodium component of salt all right normal balance is 135 to 145 mil equivalents you will probably need to know that after my class I'm not going to require you to know it now but you might want to keep that in mind for nursing school in the future if that is your next stop after here or a stop down the road after here uh we should take in about two grams a day but if you take a look at um how much sodium is in anything that's processed we take in way too much sodium especially if we are eating Foods um of a of an ethnicity that hello salt in it okay sometimes we we do but it's mostly our processed foods like I was telling my on-campus kids I said if you are reading a food label well if the food that you're eating has a food label on it it's probably not the greatest thing for you it's it's probably too processed um we sh we should get a majority of what we eat I know it's hard to do this when you're in college but we should eat a majority of unprocessed Foods so that's like meat from them from the meat store the Butcher Block you know the meat section of the store that hasn't had anything done to it hasn't made a sauce out of it or anything like that and fresh fruits and vegetables they don't have labels on them because they don't have extra stuff added to them and we don't have to worry about them as much giving us bad problems where we have to read a food label so there's my little soapbox about that all right so daily requirement there intake make oh look at that a half a gram what is this I just um can of Campbell Soup or ramen noodles or something like that that's 10 times what we should be consuming goodness steaks don't eat too much sodium all right lost in urine feces and sweat and then amount lost in urine is regulated by aldosterone ADH and ANP which we will get into all right so sodium's role in blood plasma osmolarity most important electrolyte for determining blood plasma osmolarity so whatever's in your sodium water sodium whatever's in your plasma water is going to be drained drawn towards it so our extracellular fluid will become hypertonic if your sodium is increased obviously makes sense because I have more sodium or I lost water so what's going to happen if my extracellular fluid is hypertonic water will move from the other compartments into the plasma until you get a normal um osmolarity okay number of milliosmols if your extracellular fluid is hypertonic it'll be because you don't have enough sodium due to decreased sodium or too much water and again water will move into the cells so this would be crenation and this will be lysis swelling and lysis okay so um retention so what is the effect of of retaining or losing sodium so the retention of water of sodium and water causes an increase in blood volume and pressure loss of sodium and water with opposite effects so individuals with a hot with high blood pressure are often put on low salt diets because that's making them have too much water in their bloodstream and then they have too much blood pressure okay so sodium imbalances the most common type of electrolyte imbalance is a sodium imbalance so above normal hypernatremia below normal hyponatremia and what are our what are the things we're most concerned about with those imbalances is changes in our water content because it is the electrolyte that's going to regulate water balance so we know that if I don't have if I have too much sodium too much too little sodium I am going to have potentially severe water imbalances because of that so here is where we get sodium there's where we lose sodium so what does aldosterone do retain sodium and therefore water retains it and it maintains sodium plasma blood plasma concentration and it'll always increase sodium levels all right now with ADH it's not directly related to the amount of sodium but what it's going to do is dilute the amount of sodium that you have so by retaining water it will decrease the blood the sodium blood plasma Oz uh concentration by diluting by dilution okay not because you added any sodium or you took it away you added water okay and then A and P will absolutely cause the excretion of sodium which is going to decrease your sodium concentration this is gonna this one right here is going to do it by dilution this is going to do it by elimination this will be let's get rid elimination let's get rid of the sodium let's not reabsorb it all right so um here is just what we said so either decrease water increase sodium will make the blood plasma hypertonic and water will move into the plasma from the cells by osmosis and then if I have too much water not enough sodium then my plasma is hypotonic and water will move out and into my cells okay so that's sodium I think we've been a lot on our journey so far this semester I think we've um uh spent a lot of time talking about what happens with sodium all right potassium here's just the opposite to sodium so sodium is extracellular 98 here I mean 99 here is 98 potassium on the inside and very little potassium on the outside so that's maintained of course Again by the sodium oh man they did this a lot um I thought I caught all those so um maybe I caught them in your notes so the principal cation exerting intracellular osmotic pressure okay so this is would bring water into the cells okay because you're you're increasing the osmolarity inside of the cell not outside but here is the thing required for neuromuscular activities and controlling heart rhythm um I'm sure we've said I've said somewhere in these videos if you've watched all of them to this point about um potassium is what's going to stop your heart in a lethal injection or euthanasia so um we're gonna we're gonna send you into hyperkalemia and um and then eventually your heart will go into fibrillation and it'll stop because you have too much potassium it's depolarizing much more too rapidly and and then you'll die um so and then neuromuscular activities of course neurons and neurons and muscle cells you need potassium for repolarization so very important in your body only the outside of your potassium levels are regulated we don't regulate what's inside so we're not going to kick out too much potassium you know more potassium if it's too high inside or bring it in if it's not we just regulate what's on the outside so we'll be taking a look at um uh oh aldosterone so let me just put this right here um over here so aldosterone causes K secretion in the kidneys so um if we're absorbing sodium and we're retaining sodium we're going to kick out potassium because we need to make sure we have the right amount of potassium and we have little amounts of potassium on the outside so three and a half to five mil equivalents uh extracellularly and um so typically we're excreting if we take in too much we're either going to excrete it or we're going to put it in our cells and we'll talk about putting it in our cells in just a minute so remember this aldosterone is what causes us to get rid of the extra potassium we might consume so whoa look at that the most lethal of electrolyte imbalances will cause cardiac or respiratory address address arrest sorry about that so like I said euthanasia Lethal Injections all right so total body potassium is regulated by potassium intake and output our diets is about 40 ml equivalents so that we maintain the balance within our cells and outside and we get it from our fruits and vegetables yes we do get it from bananas but we get it from potatoes we get it from a lot of different places all right most of the caves lost in urine do to aldosterone in a lot of respects and then just regular elimination by the kidneys but the amount fluctuates greater amounts are lost if plasma potassium is high so obviously if you have a lot of potassium in your plasma it's gonna oh look at that kicked out during at your kidney and then you're not going to reabsorb it because you already got too much and then increased aldosterone secretion like I said and then high blood pH so this is um uh um let's see what I was going to say about that no I will come back to that okay um so what do we want to do so we want to make sure we have the right ratio of potassium in the intracellular fluid and the extracellular fluid oh we're going to talk about this with acid-base balance because I was trying to my pause right there was when are we going to talk about this again and we will do that with acid-base balance okay and um so where we have this whether it's intracellular or extracellular is due to what the sodium potassium pumps do in those those potassium leak channels that we have in muscles and neurons um so potassium shifts we can move it into and out of the cell depending on what our plasma potassium levels are what our plasma hydrogen levels are and the specific hormones in the blood and we're going to again talk more about this when we get to acid-base balance all right um so change in blood plasma levels cause shifts between the extracellular fluid and intracellular so um with hyperkalemia we want it to leave the extracellular fluid and go into the cells um but we're going to have to do that with um with our sodium potassium pump okay and then a decrease in plasma potassium so hypocalemia hypokalemia then it'll leave our cells and go into the um exercise oh extracellular fluid and hyperkalemia if I have like way too much on the outside then it'll just go in okay um now in this case right here um if I have a chain oh I guess I'm doing it right here and not in the other one because we're still talking about potassium all right so um plasma concentration if I have lots of hydrogen ions in my extracellular fluid so this would be plasma interstitial fluid so let's say I have diabetes because I'm got diabetic ketoacidosis or I'm starving or I'm really exercising or um I'm an alcoholic alcohol consumption okay anything like that is going to make things acidic and so what the acid is going to do hydrogen ions will move into the cells and potassium will move out we'll lose potassium to help maintain an electrochemical gradient so I just had some pluses move in I got to kick some pluses out with the hydrogen ions and so and then we'll do the opposite if my blood pH Rises where I have fewer hydrogen ions then K will move into the cell okay so if I have fewer H's in the extracellular fluid then we go k into the cell which I think is just what we were saying over one more over here um okay nope that's not I was looking at okay so um no that's what not I was looking at either okay that's fine um now certain hormones this is interesting can induce a shift insulin so insulin does two things it decreases blood glucose and it decreases blood potassium by stimulating the sodium potassium pump so we pump more so more K into the cells okay so what we're doing is taking it from outside my plasma and interstitial fluid and I'm hiding it in my cells to prevent hyperkalemia and so it could potentially occur as I'm absorbing potassium from my food let's say I really like bananas and I'm eating um eating my bananas then I don't want that to stay out of my tissues or my heart may get all messed up and um and so I need to um put that into my cells and not leave it in my extracellular fluid all right so here diet same place so aldosterone as we said causes potassium secretion and that's going to decrease blood plasma levels okay keep it within this this three and a half to five mil equivalent per liter range all right then um so potassium is dependent upon potassium levels hydrogen levels and Insulin okay so if potassium levels potassium goes into the cell makes sense if potassium decreases potassium comes out totally makes sense if pH drops okay pH drops because I don't like because if we say blood hydrogen ions increases remember that is a drop in PH H's go in and K's come out okay hyperkalemia then if the pH Rises H's come out and K's go in okay and then maintaining a normal so insulin and makes glucose go in but it makes potassium go into all right there's potassium all right chloride so chloride is always going to be with sodium follow sodium by electrostatic so it's attracted so wherever sodium goes It goes because chloride will go because of its attraction and then again the amount lost in your urine is dependent upon your blood plasma levels regulated by the same mechanisms as sodium levels most abundant anion in the extracellular fluid get it in diet sweat lost in sweat snow excretions urine increase obviously hyperchloremia hypo hypochloremia and that's really all we need to know I don't really care too much about that all right then calcium we do care about calcium because of all the things that it does so most of an electrolyte obviously in bones and teeth makes it hard 99 of our calcium is stored here the rest of it's going to be extra so or is going to be um in your fluids and we move it in and out of cells due to pumps or pumps within the sarcoplasmic reticulum and um by pumping it out of the pumping it out of the cells or into the sarcoplasmic reticulum it stops binding to phosphate calcium phosphate within cells and hardening we don't want that we don't want it to turn into a mineral inside of our cells and we don't want it to do that in our blood either so um parathyroid hormone when we get to phosphate I'll talk about what parathyroid hormone is going to do but parathyroid hormone let's just mention is going to increase blood calcium levels okay so why do I need a certain level of calcium in my bloodstream muscle contraction neurotransmitter release second messenger in the endocrine system participate well not just endocrine system anytime that a cell needs um uh let's see anytime a cell is going to receive a signal so like G protein coupled reactions um not just in hormone reactions to say anything where we get signaling extracellular signaling we use G protein coupled receptors a lot and that's going to help kick in that and the fossil uh um phospholite by C so just as a messenger system all right hey so also participates in blood clotting we remember that in the intrinsic pathway and even in the uh the rest of the pathways the common pathway and coagulation that calcium helps hold things together help binds things together so obtained in diet lost in urine feces sweat just like everyone then um so increased hypercalcemia hypocalcemia okay that's all of that all right phosphate most abundant anion in the intracellular fluid and then I'm going to put um oops nope it's over here it's right there in buffer so 85 stored in bone and teeth as calcium phosphate makes things hard mineral hydroxy appetite also the rest of it is in our DNA an RNA and our phospholipids remember phospholipid bilayer um sugar phosphate ATP we put in ATP as well okay so we need our phosphate but we need to put it somewhere where calcium is not going to bind to it so we're going to put it as our intracellular buffer so when we get into acid-base bounce we'll talk about bicarbonate as our extracellular buffer so this is going to be inside of our cells and it's also going to be excreted in our urine um because pth causes it's excretion when we eat it it's going to cause us to get rid of it because it says hey you cannot bind to calcium most ionized in blood plasma so that's where we see it as the po43 but the rest is brown bound to something like a protein and regulated by many of the same mechanisms as calcium okay magnesium bone or cells second most abundant cation in the intracellular fluid here is the big thing it's an enzymatic reactions uh I had a student who he's a doctor now um and uh he was taking biochemistry and after he left EA and and then went to he went to BYU and and um he emailed me one day and he goes hey Mrs G I just I'm in my biochemistry class and we were just doing all this stuff with magnesium and then he just went through all of these things just complicated stuff and I'm just like ah way to go buddy and I was just so excited that he had you know remembered that um we I had talked about magnesium really briefly and said you know there's a whole lot of things that magnesium is in and then he proceeds to tell me what magnesium was in so I really like that um assistance sodium potassium pump important in muscle relaxation beans peas leafy green vegetables legumes lost through sweat and urine and regulated through the kidney okay does oh um muscle relaxation if you um have some muscle cramping uh you may be prescribed some magnesium um maybe if you have a um some constipation you might have some magnesium citrate that they'll give you or you may have seen something called calm calm that has a lot of magnesium in it too because it helps calm your nervous system so there's some additional things about magnesium all right um I think I'm gonna let me just go through because these are all the hormones yep let's stop here and um and then uh we'll just have a little short video left on those hormones as I had mentioned before I said oh we're going to go through these four hormones so I just want to um make sure that we have a good time to take a look at these and and understand our hormones one last time before we leave them and go to reproduction so stop the video right here and we'll see you in the next one bye