okay so globular filtration so FRS right so our first step is this filtration okay so this picture here is showing you the little podocytes that I mentioned like they're just kind of weird-looking cells that somebody thought they look like little feet I'm not sure I see that but the whole thing is it's creating two layers of that like things have to go through so this is like using two coffee filters instead of one you just want to make sure that you don't get any chunky Funky's in your coffee well we want to make sure that good stuff like blood cells can't exit the bloodstream okay so the thing with filtration is filtration is selectively so this is caused by blood pressure which is hydrostatic pressure right so it's just like when you make coffee and you fill the top reservoir with water like the pressure of that water moving through is how you make your coffee well remember with blood pressure the fact that the water is desperate to leave the blood stream when it hits that capillary bed is what kind of forces stuff out so this is non-selected filtration is non-selective Bowman's capsule doesn't really care it's just trying to grab stuff okay so all substances like waste but also unfortunately good stuff like sugar can lead now the huge stuff remember can't that's the whole point of the filter like the coffee we want to keep the coffee grounds from getting into our coffee we don't want blood and proteins to leave the bloodstream but pretty much everything else can leave so filtration ston selective so it's again like that first day I clean my closet if you're truly in the mood to spring clean you go in and you it's like a frenzy you're just Rabin's stuff right whereas if I go in and I'm like I'm gonna try to clean out my sweaters that would be selective but non selective is you're just cleaning out anything and everything from your closet you're just grabbing it all so filtration which is happening at Bowman's capsule is just grabbing it all no matter what it is you of the capillary bed itself because remember those capillary bed is holy holy and then we have the wall of the globular capsule and this little kind of thin basement membrane so that this picture here is showing that little podocytes okay just creating like a second layer on top of that capillary bed so the capillary has its wall and then it's covered with those podocytes to make sure that we can filter things into Bowman's capsule so the whole thing with the filtration membrane I just want you to know it's two layers like you've got to go through the capillary wall and the podocytes just like I said before with fishing it's like using two Nets you just want to make sure two layers of net you want to make sure you don't lose any of your fish we want to make sure we don't lose our lose our blood cells here so we want filtration to occur we have to filter our blood or we die from toxins but we just don't want to lose our blood cells you don't want a PE blood that's a bad day so this is just a little picture I stole from the internet that's just showing how we have the red blood cell trapped in there we have the lining of the capillary bed the endothelial lining which is kind of pink that has the holes we have that basement membrane in between and then we have those little photo sites so it just makes it again a double filter that's all we care about for this is there's two layers of filter there's two layers of coffee filters there's it makes it a little harder for things to leave the blood we still want things to leave the blood because otherwise we couldn't clean the blood we just don't want to make it too easy you so the globulars is a capillary so it's gonna have the fenestrations those little holes those little pores that make them leaky that's the whole point we want things to leave the blood so the globular capsule has these little podocytes kind of dangling off of it that are gonna sit on top of that cap hilarity little feet and make another layer of pores so again the whole point of the first two sentences here is you're up two layers of filtration you have two coffee filters so once that filtrate moves into Bowman's capsule or the globular capsule it's going to go into the proximal convoluted tubule once we go descending a sending distal convoluted tubule and collecting duct that's where we're officially making urine this party is filtration pressure just like we did before with capillary exchange this is not new it's just applying it in different way so it's due to hydrostatic pressure which remember anytime I say hydrostatic pressure it's blood pressure inside those capillaries the fact that the water especially inside that blood strain is so desperate to leave 'if the capillary once it hits it because it's coming off the pump of the blood or Punk of the heart that renal artery that blood is flying into the kidney when it's Forks off into an arterial remember that's like being on a highway so the Bloods still flying and once it hits that capillary there's now holes and so if I'm all crowded inside that blood stream I'm excited to leave especially if I'm water and that water's gonna have all that dissolved stuff in it skank but also sugar and other things so this is forcing stuff out just like when you make coffee and you have a full water reservoir you're gonna make coffee a lot faster then towards the end when the water runs out and the coffee is just kind of trickling out of there it's all about pressure it's just like watering in your garden if you have little kids that are running through sprinklers if you just barely turn on the hose the sprinkler system is gonna be like two inches tall like who wants to run through that that's not fun so you need a big strong blood pressure for a good squirt right we want to make sure we're squirting stuff out of the blood trying to clean it so the rate of filtration is gonna vary with the rate of blood pressure just like my sprinkler example if I crank up the pressure my sprinkler is gonna be 30 feet tall if I barely turn on the garden hose it's going to be 2 inches tall so this is one of the many reasons you need part of your homeostasis is you need a good strong blood pressure otherwise you wouldn't be able to clean your blood and you would die from skank so how can I adjust this filtration pressure is gonna change with the diameters of our garden hoses the diameters of our a ferret and our efferent arterial so it's just like if you water flower if you're trying to squirt a hose across your yard you kind of put your thumb on it right or you kind of kink your hose to get it to squirt kind of farther so it's the same thing here if I adjust the diameter if I kink my hoses that's gonna change blood flow in and out of blah meters I'm just trying to illustrate what we can do to our garden houses here so there's all kinds of different ways I can change filtration pressure so picture the globulars in your head you have the a ferret arteriole bringing it in and the efferent arteriole bringing it out so that's bringing blood in and out so I can to change be in and out so if i dilate the afferent arteriole that means I'm making it bigger so I'm going from the picture on the left to the picture on the right so if I make my garden hose bigger that's gonna allow more blood into the gwamorous right just because I've I've opened up my my blood flow here so the results going to be increased pressure if there's more blood rushing into your glom eulerís there's more pressure building up for things to want to escape and remember things can escape because the glom nervous is capillary bed that has holes in it so I'm going to filter more and I'm going to end up with more urine so if you send more blood into the globular so you're going to get more filtration you're gonna get more urine so I do that by making the afferent arteriole bigger so this is just like making like when they open like when Disneyland opens in the morning and they open all the doors and everybody rushes in have the opposite what if we constrict the afferent arterial what if instead of opening all the doors to Disneyworld I only open one well people are gonna let trickle in right like I'm not gonna ever get a big crowd if I'm not letting people in so if you're decreasing blood flow if I'm turning down the water pressure at my house I'm not gonna get a good squirt for the kids to run through which is fine by me cannot like kids so if I constrict the a ferret remember a Ference going in Bloods gonna trickle into la mueller's well if blood is trickling into that capillary bed there's never going to be pressure building up so if I in the water that's inside the capillary bed I have no incentive to leave if I'm not crowded why would I leave if I'm number one in line at Walmart why would I switch lines so this decreases filtration just like making coffee if there's barely any water in your coffee pot you're not going to get coffee so I'm decreasing filtration I'm deep creasing urine output affarin arterial so your efferent is to exit so if I make my exit real big so this is at the end of the day when they kick everyone out of Disneyland they want you to rush out of there right so if I make my exit bigger all the blood is gonna go into the glom nurse and it's gonna shoot right out of there so again I'm never we're gonna get pressure built up right the reason why things filter is the water inside that capillary bed inside that blood is very crowded well in this case if the blood is just rushing out of the globulars you're never going to get pressure built up so why leave so this again decreases filtration and decreases urine output just like if I open all the doors at Disneyland and everybody leaves I'm never gonna get a crowd if I constrict the exit so now I'm not letting anyone out of Disneyland I'm gonna get lots of pressure built up and locked to crowds right well if I'm preventing blood from rushing out of the glamorous inside the globulars which is the capillary bed pressures going to build so if I'm water especially with all the waste I'm gonna be really excited to leave that capillary bed so you're gonna get a good squirt so you're gonna have increased filtration you're gonna have increased urine so this is I only open one door to Disneyland to get in and I only open one door to get out I'm never going to get a lot of people in Disney World so if I constrict both the exit and the entrance I'm still not gonna let a lot of blood into that globular and if there's not a lot of blood in the capillary bed there's no pressure and if there's no pressure there's decreased filtration there's decreased urine output so besides adjusting the tubes going in and out of the globulars we also have just overall blood pressure so blood pressure's a part of homeostasis having a normal blood pressure keeping your blood pumping is is important for life right because Bloods delivering the oxygen and picking up the carbon dioxide delivering the sugar and picking up all the waste well at the cat the kidney level it's the same thing it's like you've gotta maintain blood pressure in order to clean the blood so increase blood pressure you're gonna get increased filtration so a strong blood pressure is important to make sure we're cleaning the blood decrease blood pressure decreased filtration this is one of the dangers of if your blood pressure starts to drop in a hospital if your patient's blood pressure is getting dangerously low toxins will start building up in their body which will kill them faster you part of this chapter okay is all of this so hang in there okay but where it gets weird is it's not all about filtration your body is not all about making urine remember this is a tug of war if it was up to the cardio the blood would never be cleaned if it was up to the urinary system that was that's all you would do would be make urine 24/7 if it was up to the urinary system you'd be sitting with a bucket under you right now that's not real convenient for modern life right plus you would dehydrate if you were peeing 24/7 there's no way you could drink enough to keep up for that loss right so we can't have either organ system when Allah it is a tug of war and ultimately the urinary system wins because we have to make urine or we die but we don't want the urinary system to win so much that we're peeing ourselves to death so this is a delicate balance so you have the urinary system pulling the water out of the blood well this example is the blood is going to pull some of the water into the bloodstream so we're fighting over water here there's a tug-of-war between cardio wanting to hold on to the water in the blood and urine area wanting to take that water and put it into the urine so up to this point we've been talking about the urinary system well now oh this is how cardio cardio holds on to some of its water so we say this opposes filtration because filtration is what happens at Bowman's capsule filtration is about pulling things out of the blood into urinary well these are factors that keep that from happening doesn't stop hop it but slows it down because we don't want to pee buckets so these are factors that keep us from from peeing buckets this key these are factors that keeps the water from just all of the water from leaving your bloodstream and we've seen this before this is that colloid osmotic pressure so call you boy just hunk comes from collagen just comes from protein right so remember we did capillary exchange we just drew a little plasma proteins on our drawing and I said blood is always hypertonic so blood is always hypertonic because these plasma proteins right water always goes from where it's crowded to where it's not so by definition water goes from hypotonic to hypertonic always so blood is hypertonic which means water is very attracted to it so the concentration specifically of albumins which are those plasma proteins is going to oppose filtration because if I'm water and I'm getting ready to leave two blood and go out to Bowman's capsule I'm gonna leave but I'm not gonna like rush out of there because I'm very very attracted to the blood so this keeps all of your water from leaving your bloodstream remember this blood is flying around in and out of Bowman's capsule like really fast so if the water delays at all it's gonna miss its opportunity and that's what we want because again we don't want to pee buckets here so we're not stopping filtration we're slowing filtration the fact that the water is anxious to leave vocabulary but it's also still very attracted to the blood kind of slows it down so increased hydrostatic pressure within the global cap sille so water pressure in the globular capsule the more full that Bowman's capsule gets with filtrate so the more we pull out of the blood if I'm water I'm not going to be as anxious to leave the blood the whole reason water wants to leave the blood is it's crowded in the blood well if Bowman's capsule gets crowded also with filtrate why would I want to go anywhere and it's not like Bowman's capsules ever really empty you're always making urine right so again both of these factors are not stopping filtration if we stop filtration we die but it's just slowing it to make sure that the water some water stays in the blood because if water doesn't stay in the blood we're just as screwed as if the waste stay in the blood right so one of the things that can screw this up is like a kidney stone and so a kidney stone will keep the filtrate from being able to drain so it will back up just like if your sewer line backs up in your house and so kidney stones will keep the filtrate from being able to move into Bowman's capsule because Bowman's capsule will get so full so it kind of will cause everything to back up but we're not quite wet ready for that it was just kind of an example so the point is this is a tug of war this is a tug of war between urinary and cardio we want urinary to win we always want to pee we always want to make urine but we don't want to pee buckets because we would dehydrate and die all this which is always sad so when I was trying to draw here is the capillary bed so it's like a tube but like if you're looking through a straw you see a circle right so I was trying to draw that and my little peas are just the proteins so if you have increased colloid pressure or decrease call you a pressure so we should be in the middle here like homeostasis we should not have increased or decreased we should just have normal okay but say you have a lot of protein in your blood well if you have a lot of protein in your blood it's probably because you're dehydrated because the percentage of protein should always be kind of consistent in your body so if that level is rising it's probably because you've lost water however if I'm water okay I'm gonna be extremely attracted to the proteins in that bloodstream remember water follow solute water always goes from hypotonic to hypertonic so if this is the capillary bed at Bowman's capsule if this is the glom II you'll arrest the water inside your bloodstream is not gonna want to leave you're not gonna want to leave to go into Bowman's capsule because you're going to be so attracted to all of those proteins so this is going to decrease your an output well if I'm dehydrated isn't that good like there are some situations during the day where you make a lot of urine and then there's times when you practically stop right so if I'm really dehydrated I want to make sure I'm holding on to my water well that happens because we've increased our blood colloid pressure call yo it just means collagen so if there's all of a sudden a lot more proteins in the blood the water is going to want to stay there consequently if you don't have a lot of proteins in your blood say you're starving well if you're starving you're not gonna have time to make those blood proteins right you're gonna be using those proteins for other things so you're actually going to make more urine you what I try to draw here I'm so bad at drawing on PowerPoint I know it's terrible what I tried to draw here was the glom Euler's and then Bowman's capsule so the black circle is Bowman's capsule and the little green in red is the little glom Euler's and then you have the white space in between where the filtrate would go so increased caps solar pressure would be if the white space got full of filtrate well if that got full of filtrate if I'm inside the blood I'm not gonna want to leave right this is like if I'm number 10 in line at Walmart and the line next to me has 12 I'm not going to leave so the more crowded with filtrate Bowman gets the less filtration can occur there's no word for the filtrate to go so this would be like the kidney stone example if fluid if the filtrate is backing up into Bowman's capsule there's no room for new filtrate if your coffee pots full there's no room for new coffee whereas most of the time you have the bottom one so the top is kind of abnormal the bottom one is normal we're decreased capsular hydrostatic pressure if there's not that much filtrate you're gonna make more urine quicker because the water inside the blood is going to look at that space in the capillary or in the Bowman's capsule and say oh yeah I'd rather be out there so that's like being number 10 in line at Walmart and the line next to us - you're gonna haul ass and knock over old ladies right so if I can go from inside that crowded capillary bed to that Bowman's capsule where there's not you know not a crowd I'm gonna rush out of there you they're just actual textbook pictures I know my drawing sucked of what's going on here okay so hi colloid osmotic pressure versus low colloid again we should be somewhere in the middle okay so hi colleague Wade osmotic pressure means you have lots and lots of proteins in that capillary bed well if I'm water I'm gonna want to stay inside the blood because I'm gonna be really attracted to those proteins I won't have as much incentive to leave and go out in Bowman's capsule so this is good like I said dehydration causes the protein percentage in your bloodstream to rise well if I'm dehydrated I want to make sure I'm sending as little water out to the urinary system as possible now you're always peeing right cuz you always have to flush out that waste but the difference is is if you're really dehydrated you maybe once a day whereas if you're really hydrated you'll be several times a day low calorie pressure means the water is going to want to leave the blood even more because if there's not a lot of proteins in the bloodstream that means the blood is not as hypertonic as it usually is so the water isn't going to be as attracted to the blood it will willingly leave and increase filtration you pressure in the capsule itself so in this picture here in Bowman's capsule or globular capsule is like the grayish blackish color okay if you get pressure built up in that black gray area why would you want to leave the blood so this would happen if something's blocking your in release so the urine Neri system we're going from Bauman's to proximal descending a sending distal collecting duct if something blocks the collecting duct everything's gonna back up it's just like if something clogs your sewer line things back up so this can happen due to kidney stones or an enlarged prostate gland fluids gonna back up well if Bowman's capsule get it's too full there's no room for the new filtrate to form so there's no place for the urine to go right so it's gonna stop filtration or slow filtration low hydrostatic pressure is going to increase it so if there's nothing in Bowman's capsule the water inside the capillary bed inside the Glomus is going to be really excited to leave and you'll be more you know this stuff is ridiculously complicated okay but making urine is ridiculously complicated it has to be because if you make too much urine you're going to die if you don't make enough urine you're going to die but the problem really with the urinary system is you can't make the same amount of urine every second of every day there are some days like today I'm sitting out on my back porch it's 80 degrees there are some days it's 80 degrees there some days it's 40 degrees your water needs are very different on an 80 degree day versus a 40 degree day and I'm just sitting here what if I was going for a run [Laughter] it's adorable never gonna happen but if I was running my water needs would be very different than if I'm just sitting on my couch like I am right now so temperature activity levels food say you have soup for lunch versus a cheeseburger cheeseburger sounds pretty friggin good well there's more water in the sea then in the cheeseburger which means you maybe don't need to drink as much which means you may or may may or may not make more urine so the thing is with the urinary system is every single second of the day is different and your kidneys have to adjust to that because sometimes it's hot sometimes it's cold sometimes you're running sometimes you're sitting sometimes you're sweating a lot sometimes you're shivering like sometimes you're running a fever like there's just so many factors that affect whether or not you need more or less water at that moment and your kidneys are ultimately in charge of releasing that water or holding on to it depending on need so we need this guy to be able to change all the time which is why we have all these pressure things it's crazy so point is from this picture because we're not doing math I know math scares you okay the point of this picture is to show that we are constantly battling between cardio and urinary this is a tug-of-war and somebody has to win urinary has to win we have to flush these toxins but we don't want urinary to win too much so it's like little kids when little kids play sports and they don't keep score we always know who wins even when we say we're not keeping score we know who's winning because life's about winning and we keep score right but when you watch little kids play sports like four-year-olds play t-ball you don't sit there and hope one team just like pummels the other like if you go to a Cub Cardinal game you want your team to win and you don't care if the other team scores at all you're like suck it suckers I'm a winner chicken dinner okay but in this situation we don't want four-year-olds to get pummeled so even if one team is really good and the scores like 20 like you want the other team to please get like five like you want them to at least score some points you go to professional sports you hope the other team gets zero but little kids you want them to get something right so that's how this is we want the cardio to win a little bit overall urinary has to win otherwise we die but we don't I want it to be a blowout we do not want to pee buckets we do not want the urinary system to win so much that were peeing 24/7 so we have this tug-of-war so let's start with the the globular hydrostatic pressure down there in the corner that says out 60 to 60 millimeters of mercury it's just a measurement of pressure just think of it like oops so if there are 60 votes to eat pizza for lunch so we have 60 people saying let's eat pizza so globular hydrostatic pressure that is the blood pressure that's built up inside that capillary bed so when the blood comes in through the afferent arteriole remember it can't escape eight the water can't escape the afferent arteriole the arterial does not holes in it when we hit the capillary bed the water's crowded and wants to leave into Bowman's capsule taking the sank with it so that's just hydrostatic pressure it's just blood pressure like we did before with capillary exchange so there are 60 votes saying let's make urine 60 votes for pizza well that's not the only votes we have okay so now we have factors that are opposing filtration so we have the fact that if you go to the right upper corner there call you osmotic pressure so remember there are proteins in that blood that are saying hey water don't leave stay with me so this opposes filtration it's not stopping it it's slowing it down the fact that water is not that excited to leave because it's attracted to the proteins inside the foot so this is about 32 votes for tacos so we have 60 votes for pizza 32 votes for tacos another factor that opposes filtration or slows filtration is capsular pressure which is in the bottom corner so the fact that as the filtrate drains into the capsule Bowman's capsule it's gonna start to get crowded well the reason why things leave the globular is the reason why water and skank leaves the capillary bed is because it wants to improve its situation just like at Walmart I want to go from number 10 in line to number zero so if I can go from 10 to zero I am hauling ass and knocking over old ladies but say the line next to me has 8 if I can go from 10 to 8 I'm still gonna move but I'm probably not gonna be as like excited about it right I'm probably not gonna rush and I'm probably not gonna knock over any old ladies so capsular hydrostatic pressure is the pressure that builds up in Bowman's is gonna slow filtration because the more filtrate that gets produced the less reason I have to leave the what just like as the longer the line next to me gets at Walmart the less reason I'm gonna leave my line so there's 18 boats for tacos so if we add it up we have 60 votes for pizza and 50 votes for tacos the pizza wins the urinary system wins we want it to win but instead of winning by 60 points and blowing out the other team we only win by 10 so this keeps us from peeing buckets if it was up to the urinary system you would have 60 millimeters of mercury pressure shooting out squirt now there you'd be peeing buckets but because the water is attracted to the bloodstream because of the colloid the collagen proteins and the fact that as Bowman's capsule fills up there's not as big of a reason to leave that opposed this filtration with 50 millimeters of mercury we then are making urine at a rate of 10 so we're still making urine we always want the urinary system to win we just don't want it to be a total blowout where we will dehydrate we will pee ourselves to death in like 10 seconds you