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BIOL 3324 Human Physiology - BIOL3324_lecture20_1107
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00:01 All right, y'all, you guys a good day. Yeah, it's
00:06 be raining on Thursday. I think heads up because I know you guys
00:10 to know about these types of All right. Um I made a
00:16 . Um I don't know if you the promise, but I said today
00:18 the most difficult day in terms of rest of the semester. Um And
00:22 not doing that again to scare I'm just trying to kind of perk
00:25 up to say, all right, a part where I'm gonna need to
00:28 attention and I'll point out was I'll say this is the time.
00:32 ? Right now, this is not time this actually uh this part of
00:35 lecture is actually pretty straightforward and we describing how a kidney goes through the
00:41 of filtration. We were looking at Nephron and we said, hey,
00:44 plasma is flowing into the glomerulus, glomeruli uh fluid is being pushed out
00:50 a series of pressure, right? Those pressures collectively are referred to as
00:54 net filtration pressure that drives fluid into tubular portion. And now we have
00:59 fluid, which is more than more than we are trying to get
01:02 of. And so we need to modify it. And what we call
01:06 filtrated fluid is just the filtrate. right, it's not urine yet.
01:10 won't be urine until the end of class. Ok. So what we're
01:14 do next is we're going to reabsorb materials, the body wants to keep
01:20 the body. All right. So gotta think about it like this,
01:23 tubule is outside the body and we're to move things from outside the body
01:28 into the body, right? And that's what that first step is
01:32 Now, this is very, very . We're only gonna take in those
01:36 that we want to keep most of takes place in the proximal convoluted
01:43 So whenever we're talking about this we're just, we're just sitting up
01:46 at that front end. All Um We've already mentioned we're trying to
01:50 the things that we want. So statement I have a high reabsorptive capacities
01:54 the substances the body needs. That's I'm saying is if your body
01:58 it's going to keep it and anything your body doesn't want is just going
02:01 allow it to keep on flowing with filtrate. Remember what the filtrate
02:06 It is plasma minus the plasma right? So even though we give
02:11 a special name, it's not that different than what we've already started
02:15 All right. Um And so there's processes that we're gonna be looking at
02:19 or, or generally not looking but just generally that are taking place
02:23 that we have cells. And so have to add the pass through the
02:26 or have to pass between the So we're gonna take advantage of either
02:30 those two simple processes. I know seems stupid that I say that.
02:34 . All right. So what are gonna do is we're gonna pass through
02:36 cells or we're gonna pass in between cells. And so everything is gonna
02:40 dependent upon the permeability of those cells particular substances. And this is where
02:46 fall back on something we learned a time ago. You're like crap.
02:51 hope I didn't have to something I forgotten. This is actually pretty
02:56 Wherever sodium goes water follows, you that wherever water goes, everything else
03:03 . Taking into consideration osmotic uh ideals osmotic characteristics. All right. So
03:09 know that you know the rest of story of perme or the of this
03:13 of reabsorption. All right. if everything starts with sodium, we
03:18 need to know what sodium is OK. So in the first
03:22 sodium, 70% of the sodium or as it says, about two thirds
03:27 the sodium in the uh filtrate is to be reabsorbed through the uh proximal
03:34 tubule. All right. And this the stuff that we care about.
03:38 . This is where we say when the reabsorption is taking place at the
03:41 end over here in the pro this why. So it plays a pivotal
03:44 in the reabsorption of water, reabsorption glucose, reabsorption of amino acid reabsorption
03:49 just you name it. It's It's being reabsorbed. It starts with
03:54 because wherever sodium goes, water follows wherever water goes, other things follow
04:00 with it. All right. 25% of the sodium is gonna be
04:05 in the loop of Henley. All . Now, we're gonna, this
04:08 part of the thing that's gonna make , the that section if I say
04:11 difficult thing, this is part of role. And so what we're gonna
04:15 is we're gonna use this sodium to create an environment so that our bodies
04:21 create urine's ovarian concentrations. So we're describe that later. But that's the
04:27 why is because of the way that is being reabsorbed in the loop of
04:31 . The third place is the stuff your grandma cares about. Not you
04:35 much because, well, you're young you don't care about salt intake.
04:39 you know, grandma, she sits and looks at that salt and wonders
04:42 or not I'm gonna put it in food, right? And the reason
04:45 that is because sodium load becomes important is measured and it's in the distal
04:51 tubule where it has a key role ensuring the proper extracellular fluid volume.
04:58 other words, blood pressure is dependent salt. I'm gonna put that in
05:02 because it's not really true. It's true. All right. But the
05:07 of salt in the sodium reabsorption allows to bring water back into the body
05:11 this particular place. And it's what regulate to make sure water, our
05:15 salt balance is correct. All So your blood pressure and all the
05:20 pressure meds that everyone takes is focusing . All right. So three different
05:26 , three different rolls of sodium and are the key, the key
05:32 So let's look at the proximal convoluted . All right. So on the
05:39 side, so the Luminal side is the tube. This is where you're
05:42 see sodium channels, sodium glucose sodium exchangers. All right. So
05:49 in all three of these cases, am I doing? I'm moving sodium
05:53 its concentration gradient into the cell. this is a trans cellular transport.
05:58 right. Now, granted there is uh secondary active transport that's taking
06:03 but it's with the other materials, glucose and the amino acids. So
06:06 not really talking about them right So sodium goes into the cell and
06:10 I put sodium in the cell to sure that there is still flow into
06:13 cell, I need something to pump out of the cell. And so
06:17 the interstitial fluid side, I'm going have sodium potassium pumps. So what
06:21 doing is I'm allow sowing sodium which a higher concentration in the tubule than
06:25 the cell to move into the I pump it out. And so
06:28 creates a constant flow of sodium back the body. So far. So
06:33 , pretty straightforward, right, So sodium gets moved into the
06:40 moves to the other side of the into the interstitial fluid. So water
06:44 attracted to the sodium. So water now, where is water going to
06:48 ? Well, it can go through cells. We have aquaporin in
06:51 Aquaporin can be found throughout the, Nephron. We have aquaporin that are
06:57 open in the proximal convoluted tubules. water always follow sodium in the proximal
07:01 tubules. But when we get to distal end, so when you get
07:04 to the distal tubules, you get to the collecting ducts, you get
07:07 to the collecting tubules, the aqua are gonna be introduced at specific times
07:13 that you what you say is that exist in a closed state so I
07:17 open and close them based upon All right. So I'm gonna move
07:24 in when my body needs water further . But over the approximal co theta
07:31 water follows sodium easy peasy. All . There's also tight junctions that aren't
07:37 tight junctions, they're leaky. So leaks in between the cells as
07:42 Again, following salt. Now, you went back and tried to remember
07:48 the little tiny, stupid little anecdotes tried to make. I said sodium
07:52 water are like the cool kids at . And we said chlorine was like
07:57 , the guy in the friend right? So chlorine is gonna go
08:02 sodium goes, right? It's attracted to sodium. So it's going to
08:08 chlorine. So that's an easy thing do passive. You don't need any
08:15 to do. So just follows it as electrical gradient, potassium, potassium
08:21 gonna follow water because water is now an osmotic gradient. There's less or
08:27 more potassium now than in the interstitial . So potassium is gonna move into
08:31 cells. Now. Uh this is be done through paracellular rather than through
08:35 cellular mechanisms. When you get into nephronic loop, there's some uh res
08:40 there as well. Well, we're ignore that for right now. And
08:43 ultimately, when we get to the tubules, uh we're going to reabsorb
08:47 potassium. Actually, what we're doing we're doing an exchange here is potassium
08:52 protons and these are gonna be done the type a intercalated cells. So
08:56 absorb potassium and I give up a . And what do we say type
09:02 intercalated cells? What were they responsible acid secretion? So that's what really
09:07 the exchange is there. So that's you get rid of the extra protons
09:10 of your body. So, so as anything weird sodium goes in.
09:15 water goes in. So chlorine goes . So potassium goes in. So
09:21 goes in. Where's glucose going? , it's moving along with the sodium
09:26 again being pumped the other direction so . Does it sound like things that
09:30 body wants? Does your body want ? Did you stand in line at
09:35 long time at the chick fil A here to get your glucose?
09:40 Yeah. Uh huh I didn't even she, you're eating your chick fil
09:43 . So how long would we How long a wait was that was
09:45 30 minutes? 30 F-15 man. a long time to wait for good
09:54 . Then your amino acids, your acids are gonna do the same thing
09:57 got these co transporters. So sodium in amino acids going in, they're
10:02 the osmotic gradient as well. And we get to the weird one,
10:06 old urea, nitrogenous waste in Uh If you're not aware of
10:11 we don't just produce uh urea, actually produce a whole bunch of different
10:16 . So you have urea that's from breakdown, uric acid that's from nucleic
10:19 breakdown, creatinine, that's from creatine . So you're, you're producing different
10:25 of nitrogenous waste. And so uh of those are being produced, they
10:30 have to, uh, leave the . Um, and actually we're really
10:34 when it comes to uric acid. , and I'm not gonna go into
10:37 , but that's uric acid is the that leads to gout when we can't
10:41 uric acid properly. Um, that's gout is, but we're more interested
10:46 urea because that's the primary form of waste. All right. So,
10:52 what we said about Yuria, urea slow. They're like your slow
10:57 Actually, I don't know if I've explained Uria to you. Have I
11:00 I, OK. So you're like slow friend. They, they,
11:02 still follow along. It's, it's of the crowd, right? It's
11:06 the fringes. It's cruising along with , but it's a lot slower.
11:09 , it's the dumb jock friend, know, I mean, again,
11:12 got to think of the stereotypes and he the, the what? You
11:16 , whatever. All right. So follows along but it does so
11:22 It doesn't, it doesn't reabsorb at same rate. And what ends up
11:26 is, is that in the proximal tubule, you reabsorb about half of
11:30 Urea that's located in the filtrate. then when you get down to the
11:34 of Henley, then the loop of says, no. Uh II I
11:37 you back in the body. So starts pumping it back out and so
11:41 get rid of it all and then slowly moves back in, when you
11:44 to that distal end of the So down in the collecting tubes.
11:48 so what ends up happening is instead getting rid of all the urea that
11:51 body is producing, you maintain a amount of urea in your body.
11:58 in particular, that urea becomes really important because it's gonna play a
12:02 along with the sodium to help maintain create that osmotic gradient that I keep
12:10 to. OK. So it's there a reason. It's not just,
12:16 , we can't get rid of it we just live our lives. All
12:20 . So how many slides was Like 12, something like that?
12:26 don't know. 10. All And so that took us 12 minutes
12:30 go through. You already know how Nephron works. Wherever sodium goes,
12:35 follows wherever water goes, all the things follow. And it's as simple
12:41 that. Anyone who teaches you they're just trying to make it scary
12:46 , and hard. OK. So the first part. So we
12:52 we have all this stuff that we wanna keep, but it's stuck
12:56 So we move it out through that of reabsorption. We start off with
13:00 um what was, what did we ? It was 100 and 20
13:03 100 and 20 mil. And so we're doing is we've removed roughly 19
13:08 , 100 and 19 mils back into body of water and all these salts
13:12 glucose and amino acids. All But there are things in your body
13:19 either can't be filtered or are not efficiently. And so there are things
13:24 want to get rid of. All , you guys have heard about the
13:28 of consuming poppy seeds, right. . If you go have a poppy
13:33 bagel, are you supposed to go a drug test that week? That
13:37 ? No. All right, because down the poppy seed results in a
13:44 signal for opiates because poppy seeds are seeds of the poppy plant, which
13:48 where you get the materials for It's basically an opiate. All
13:53 So what this is, is a that's telling your body is metabolizing
13:59 And so you have toxins in your and sometimes you can only get rid
14:03 the toxins at a very specific In other words, at the rate
14:06 filtration, but some toxins, you want to get rid of a lot
14:11 . And that's what the third process . Is this process of secretion.
14:16 right here, what we're doing is doing a type of trans cellular
14:20 It needs to be active because what are doing is we are grabbing things
14:24 saying I am pumping you into the . So we're going from the blood
14:29 the tubule, we're not filtering, is blood that has gone through the
14:33 process is now moving through the peritubular . All right. And what does
14:39 mean again next to the tubule? . So these are uh capillaries that
14:45 right next to the tubule. And you have machinery carriers that are literally
14:50 of binding certain molecules and moving them and across the tubular surface into the
14:59 . Now, two things that are , really simple is the potassium and
15:03 protons. All right. So proton is gonna occur along the entire length
15:08 it's gonna be dependent upon your acidity the body body. The more protein
15:12 eat, the greater acidity your blood . All right. Vegetarians have less
15:18 blood, meat eaters have more acidic . It's just a function of eating
15:22 or proteins. All right. So that happens, the body says uh
15:27 I don't like that. So, I need to do is I need
15:29 get rid of those protons. And this is what you're using is using
15:33 mechanism to get rid of the right? Intercalated cells in particular are
15:39 for get getting rid of those protons exchange for reabsorbing potassium. But what
15:44 it say? It says across the length? I'm gonna go ahead and
15:47 . I'm trying to get rid of because I'm trying to maintain a very
15:51 blood. What about potassium? in the proximal convoluted tubule, we
15:58 abs reabsorbing the potassium, right? followed the water, it's in the
16:03 convoluted tubule where you're seeing potassium All right. And here what we're
16:09 is we're trying to maintain the appropriate concentrations. All right. Now,
16:15 me ask you a question. If were uh uh potassium deficient. What
16:19 you gonna go do? Eat a ? Actually, it turns out bananas
16:23 as potassium rich as we think they . But that's what we all
16:26 That's what they told us. So what we're gonna do, right?
16:29 so you can imagine, I'm just when I'm uh potassium deficient, one
16:33 the things I I know to do go eat my bananas. But one
16:37 the things your body is doing is , oh, instead of it going
16:40 and peeing it out, I'm gonna ahead and pull it back from the
16:42 . That's what it's trying to do it's doing it at the level of
16:45 convoluted tubule. All right. I know why this isn't advancing, but
16:50 we go. All right. So concentration is high in the plasma.
17:00 what it's gonna do is it's gonna into interstitial fluid and from the interstitial
17:04 , it's gonna be pumped by the potassium pump. All right. So
17:10 , that's what we're dealing with here in the distal convoluted tubule. All
17:15 . So what we're gonna do is going to exchange it. So the
17:18 that you should be looking for is here, right? So, if
17:20 get high potassium, right? What's happen is is I am going to
17:26 it into the tubular cells, So this is secretion. Look which
17:30 I'm going, I'm going out of body out into the tubule so that
17:34 can be secreted. So I pump into the tubular cell and then it
17:39 through its potassium channel and out it goodbye. Good rhythms. All
17:44 And what do I exchange for Well, I have exchangers as
17:49 Actually, that's not right. Oh saying, yeah. So here is
17:55 exchange is taking place paracellular. But me point this out and make it
18:00 , really crystal clear. The thing becomes really important about this. The
18:06 that I use to determine when I potassium out of the body is dependent
18:13 the hormone aldosterone. All right, is what aldosterone does when I am
18:22 low in water or basically my blood decreases. Or if my potassium levels
18:28 , what's gonna happen is that results a production of aldosterone from the adrenal
18:33 that aldosterone acts on the de the principal cells in the distal convoluted tubule
18:38 causes them to do two things. , increased number of sodium potassium
18:44 When I do that, I'm gonna pumping potassium out of the body.
18:48 also doing what in the name sodium pump and potassium potassium out of the
18:57 . So what am I doing? coming in? And where sodium
19:01 water follows. So that's gonna be blood pressure. All right, that's
19:06 idea is what it's doing there. if I just pump potassium into those
19:10 cells, it still needs to have way to get out of the tubular
19:13 . And so this is causing those cells, those tubular cells to introduce
19:18 potassium channels. So the potassium can flow on out. So, aldosterone
19:22 the hormone that's being produced to allow to secrete the potassium. But you
19:29 it also as a secondary role, we'll get to it. I've already
19:32 told you, it allows me to sodium into the body. And if
19:35 pump sodium into the body, I water in the body. If I
19:38 water in the body, I raise blood pressure. So aldosterone has a
19:42 role allows me to secrete the It allows me to increase blood
19:49 Ok. Yes, sir. By it's sorry, it should be a
20:01 amount of potassium in the body, ? So the idea is I'm trying
20:05 get rid of potassium. I wanna it. It's not, I'm not
20:09 low. That's I I'm backwards. my apologies. Good catch gold
20:17 I don't pass out gold stars every . I should though. But there's
20:23 else that you put in your body I already mentioned it. I said
20:25 the poppy seeds, right? Uh day, all day long, you're
20:30 materials and you are building up toxins your body, right? And so
20:34 body wants to get rid of So, um let's do it this
20:41 . We'll see how, how knowledgeable are on your drugs. How often
20:45 you allowed to take an Ibuprofen every hours? How often are you allowed
20:52 take acetaminophen? Four hours? How an Aleve 10 man? Why do
21:04 know all these things? Doctor Because I have four kids and you
21:06 to manage fevers sometimes. All Why do they all have different
21:13 I mean, they all do the thing, right? I mean,
21:16 mean, some are in a, are not some working the liver,
21:19 are processed through the kidney. But , why, why do they all
21:22 different times? What do you think , what half life? Ok.
21:31 yes, that's what I'm looking for basically they're metabolized differently and so they
21:35 metabolites at a specific rate. And there's another half which we'll get to
21:39 a second, which is their plasma . All right. But in
21:42 you break them down and if you them down faster than you can get
21:45 of them, those toxins will build and cause all sorts of horrible problems
21:49 you, right? So this is . You can do the same thing
21:54 vitamin C, right? You notice , have you ever, do you
21:58 eat vitamin C? Do you take C. So when I was,
22:02 I was just like, y'all's you know, you go down to
22:04 GNC and you'd get like a big of the, the orange flavored,
22:09 know, vitamin C and it's oh, I don't know, sweet
22:12 , you know, just start popping . All right. But if you
22:15 read the back, it's like, is the maximum amount you can take
22:18 a day? You guys know 3000 after 3000 mg, you're starting to
22:25 into toxic doses of vitamin C. ? Yeah, don't, don't do
22:30 . That's bad. It starts destroying . All right. But basically you
22:34 , there's a certain rate at which can get rid of the vitamin
22:37 All right. Now, the process filtration is a fixed rate.
22:44 So that's what we talked about the , right? The glome filtration
22:48 it sits more or less at at a constant rate depending on what
22:52 doing. I mean, if you're up sitting down, it makes small
22:55 to maintain within a certain range. so the fluid that happens to be
23:01 the materials that happen to be in filtrate at the time are gonna be
23:04 at that rate, right? But I have something I need to get
23:08 of, I'm gonna use this method secretion so I can get rid of
23:13 faster. All right. So this why we end up with like poppy
23:18 and stuff in our body or not seeds, but the the stuff.
23:21 so what we have is we have incredibly unique system that is highly
23:26 And beyond what we're going to talk here in the class because there is
23:29 one molecule, there are hundreds of specialized carriers that recognize anionic metabolites and
23:38 capable of binding them, grabbing on them and then moving them over into
23:43 filtrate. This is what some of look like. Ok. That's what
23:48 trying to show you these molecules that listed down there. Actually, I
23:52 anions, it looks like I was . It's C ions, my my
23:55 . All right. So what this is you're no longer dependent upon the
24:03 rate to get rid of the Your body is looking for ways or
24:07 discovered ways to get rid of toxins a faster rate than normally would occur
24:14 of this process of secretion. So not just potassium and it's not just
24:21 , it's metabolites of things that we . All right, whether it be
24:26 we eat or drug we take, it's a hormone that we're breaking
24:33 This is what this mechanism allows us do and it hastens the rate of
24:40 so that their toxic levels do not . Ok. So, so
24:47 so good. So the process that nephron goes through three steps, first
24:54 is filtration discriminate, non discriminate, discriminate, just pressure is just
25:06 it's bulk flow, absorb or Discriminate, non discriminate, discriminate,
25:13 picking, picking the winners and the . And then finally, secretion,
25:18 , non discriminate, discriminate, it's which things are going. If you
25:25 have the right channel, the right to pick up the thing, then
25:29 thing is stuck in the blood and follows all the rules. I
25:33 all this, you know, the example I used, I used to
25:37 and I apparently I just confused everybody no one really learns the law of
25:41 law of mass averages or law of action as well as they should.
25:47 you can imagine in circulation, let's you have um four molecules, I'm
25:53 stay with simple numbers, right? let's say you filter two,
25:58 But let's say that those are free . Let's say you have also four
26:02 bound up, right? And I to get rid of more of those
26:06 . The way that I can get molecules unbound is by removing them from
26:11 environment, right? The the the ones. Did you guys learn that
26:15 one point a long time ago in ? Two, maybe, maybe
26:20 you learn that this idea of free bound molecules. OK. Um When
26:25 saw the furrowed brow that scared me a moment, but then it was
26:27 , oh yeah, yeah. All right. So one of the
26:30 that we're doing here is we're forcing out of the system faster because you're
26:36 with the ratios of free to bound . Because if I'm moving, if
26:41 removing bound molecule or free molecules that means they're getting unbound quicker,
26:46 I can pick them up faster if makes sense. But if that confuse
26:51 don't worry about it. Just understand is a mechanism of quicker removal.
26:59 , are you with me? Three ? Yes, sir. Almost.
27:08 quite well. Maybe. Now I think about pocket M and MS and
27:16 this is true, well, so Pocket M and MS, those
27:21 be like your bounds. Can't, eat a pocket M and M until
27:25 becomes a hand. M and you're gonna remember that till the day
27:30 die. You know that right? gonna be 40 years old and you're
27:33 explain to your kids in a biology . All right. This I think
27:37 understand. M and MS and All right. Are you ready to
27:46 on to something different? How many you have ever peed in a
27:52 Everyone better raise their hand. If been to a doctor, you peed
27:56 in a cup. And what are doing? They ask you to pee
27:58 the cup. They put you put on the tray with your name on
28:01 , right? Have you ever do ? And then they go take your
28:06 why are they doing this? What they checking on? No, unless
28:12 a drug test. All right, doesn't care if you're on drugs,
28:16 you're lying to him. In which he needs to know or she needs
28:18 know. So that whatever they're prescribing you is not contraindicated. What
28:23 doing is they're checking your GFR. , typically they don't need to do
28:28 specific test that we're about to But usually what they're doing is they're
28:32 at your creatinine levels and they look your creatinine levels in the blood and
28:36 creatinine levels in your urine. And they measure your GFR based on that
28:40 GFR being your glomerular filtration rate, ? And your GFR is an indicator
28:46 kidney function. If your GFR is relative to the average, that means
28:50 kidney is not working appropriately. So one of the things that they're always
28:55 when you go to the doctor, check your blood pressure with the little
28:58 single mammon meter. See I got off without thinking about it right.
29:04 check your blood ox with the little oximeter, right? And then they
29:10 go pee in a jar or pee a cup and then set it on
29:13 tray and then a couple days you can log in and you can
29:16 your numbers right. And they're looking your, you know, your GFR
29:21 that relative to your blood. the proper way to measure GFR through
29:27 function is making sure, you know much stuff is actually there because they're
29:32 creatinine production is constant and it's I mean, if you work out
29:38 frequently you're gonna make more creatinine. ? If you're a lump on the
29:42 , you're gonna make less creatinine. ? So, it's, it's
29:45 it's a very complex form. You actually go look it up on
29:49 They actually show you it's different for Americans than it is for,
29:53 uh Western Europeans. And they have formulas for everybody. You know,
29:58 , it's a load of fun, ? But what you can do is
30:02 pump somebody full of inulin, not pump, people full of insulin.
30:07 things happen. All right. So pump them full of inulin. What
30:11 inulin? Anyone's gonna quickly Google that boy. You don't have to.
30:16 were you inulin is a molecule that's in uh plants and it is a
30:25 that can be filtered through the filtration of the Nephron. So it's actually
30:31 small, even though if you look up, it looks really big and
30:34 , I think it's based, it's type of sugar if I remember.
30:37 . I can't, I'm not 100% , but it can't be filtered or
30:42 , it's filtered, but it can't reabsorbed and it can't be secreted.
30:47 if you go and measure, you , if you put in a uh
30:50 certain amount and then they go peak little bit later, you can
30:54 and then you go take the you can measure the inulin in the
30:56 . You can measure the inulin in urine. And then using those two
31:00 , you can then determine whether or your kidney is functioning by filtering
31:05 that, that inulin at a constant at a specific rate. So that's
31:09 they're doing here. And I'm gonna to bet that 100% of you have
31:14 had to be injected by it with because it's not something they do that
31:19 anymore. Now, it's all about formula. All right. But that's
31:22 best way to do it because you , you're putting in a constant amount
31:25 a finite amount or a fixed amount then you can measure it. And
31:29 you can use a formula like this a time course to see. All
31:34 , is this right? So, my concentration of urine of the
31:37 uh what is the volume of urine I'm collecting? Divided by the concentration
31:40 the inulin in the plasma that will you your GFR, I'm not gonna
31:44 you that formula. I'm just saying , it's a simple thing that you
31:46 measure right? Because it's being And what this is an indicator of
31:52 your ability of your kidney to filter specific amount of plasma from or of
32:00 substance. This is what plasma clearance . And I'm gonna, I gotta
32:03 the definition out loud because if I it wrong, I'm gonna screw it
32:06 for all of you. OK. clearance is simply the volume of plasma
32:13 of a particular substance per minute. it's not like, oh I cleared
32:19 a couple milligrams of the substance. saying the volume of plasma. So
32:26 what you're measuring is the volume of having been cleared over that period of
32:32 per minute. All right, different have different plasma clearances. Going back
32:41 the example, we used Ibuprofen, . I don't know what a leave
32:48 . I never bothered learning, but substance they're all cleared at different
32:54 And so if you took Ibuprofen every hours, because you're not clearing it
33:01 enough, Ibuprofen would build up cause if you are taking acetaminophen,
33:09 Actually, we found out it was more toxic than we realized. You
33:13 that about f four or five years when they're like, everyone stopped taking
33:17 and everyone stopped taking acetaminophen. They , it's there's a certain threshold at
33:22 point it becomes highly, highly So it's, you know, but
33:26 it's like every four hours, you clear out a dose of acetaminophen of
33:31 is it? 500 mg, I , or maybe 1000 mg, you
33:35 clear that out in four hours. if you take 4000 mg, you're
33:40 your luck. So what this really is it demonstrates like, hey,
33:46 , different drugs, do different So I need to be careful what
33:49 take and when I take it you suffer from horrible, horrible head
33:55 not migraines, just headaches or you can count but taking acetaminophen or
34:01 doesn't do any good. Does Yeah. Um, but like if
34:05 have kids, I'm, I'm gonna , I'm gonna use this example.
34:08 works for headaches too. I'm gonna you something here. I am not
34:13 medical doctor. All right, I'm to information I received from my medical
34:20 and all the nurses we worked with we had, we're dealing with our
34:23 and when they were sick. All . And they say, look,
34:27 you have a high temperature or give them a, one of the
34:31 , acetaminophen or Ibuprofen. All Now we said Ibuprofen is every six
34:36 . So the next time you can Ibuprofen would be six hours later,
34:39 ? But if you've ever had a baby at two o'clock in the
34:42 you're desperate to get them to be , right? And sometimes bourbon is
34:47 the best solution. I've got three to laugh at that one. All
34:55 . So what do you do? have a fever, you gotta put
34:59 down, you gotta get them So what do you give them?
35:02 you go ahead? It's like four later. Do you go ahead and
35:04 them the Ibuprofen? Yeah, you give them at the three hour
35:09 you can give them the acetaminophen and at the six hour mark, you
35:14 give him the Ibuprofen and then three later, you can give them the
35:17 and then you can give the So if you're struggling with like a
35:21 headache that won't go away, you do the same thing to yourself because
35:24 allowing the drug to clear based on plasma clearance, right? Acetaminophen,
35:31 actually have that wider swath. But also giving a medication in this particular
35:37 , the NSAID to deal with the without interfering or losing the the other
35:45 . And just so that, you Ibuprofen, like I said, that's
35:48 through the kidney acetaminophen is processed through liver. So you're affecting two different
35:53 . You're not killing both things at same time. So plain appearance is
36:02 because it tells you how quickly you get rid of a substance. All
36:07 , and all these things. go ahead. No. So this
36:14 solely how quickly it lo the that unit of blood loses that substance over
36:20 , right? So notice it doesn't with, you know, can I
36:23 the material or you know, what the rate of metabolism? It's simply
36:27 rate at which you are clearing it the blood. Yeah, say
36:34 do they have a chance to. they wouldn't, they, since they're
36:39 roughly the same thing, they're not competing. But what they're doing is
36:42 overlapping the, the functionality of that . So, the effect is so
36:47 the effect, more or less stays over time, at least with the
36:50 of the ibuprofen and the acetaminophen. . So that would be, the
36:54 is like, oh, man, got this, you know, toddler
36:58 at the top, top, top their lungs, their fever has come
37:01 . What do I do? You , I can deal with it and
37:04 not gonna poison them, which is really important thing when you're a parent
37:07 poison your Children. That's, that's bad thing just in case you didn't
37:12 . So this is a little chart kind of shows you plasma clearance so
37:16 you can visually see this. All . So this would have been inulin
37:20 here, right? So you get but you get no reabsorption, you
37:24 no secretion. And so what you say is that the plasma clearance rate
37:29 a substance that is only f but re reabsorbed or secreted is the same
37:34 the GFR Du. That makes right? If it's only being
37:39 it's got to be the plasma clearance gonna be at the rate at which
37:42 filtered. All right. But we some substances that will be filtered and
37:47 reabsorbed, but they're not secreted. typically what we'd say is that their
37:51 clearance rate is less than G the again, that makes sense. So
37:56 filtering it, I'm returning it back the body, you know. So
38:00 of them are gonna be returned some of them are gonna be returned
38:03 partially. But as the end result if I go check the urine,
38:08 gonna have less than what was So that makes sense. All
38:12 So an example of complete would be , right? We work really hard
38:17 that glucose. So put it back the body urea. We already said
38:21 just slow. So that's why we up with half of the urea that
38:25 uh filtered is um gonna be secreted excreted. Um The last one is
38:31 where we have a substance that is and secreted but not reabsorbed. Then
38:35 filtration rate is greater than the All right. So many of the
38:40 protons in your body, that rate removal is far greater than just filtration
38:46 . So, that was what I trying to get to so far.
38:51 good. All right. OK. here, easy subs or easy structure
38:58 now. Ok. Bladders. What's purpose of the bladder to store urine
39:05 that we don't make messes everywhere we . No one thought that was
39:13 Are we not a potty humor No, no potty humor, maybe
39:18 little bit. Ok. All We're making about a mil per minute
39:23 urine. Right. So, right , as I'm talking, I've been
39:28 for 40 minutes. You've made 40 of urine each. You're a pea
39:34 class. Anyone making puddles, you have to tell us if you
39:44 Yeah, I thought we were friends here, you know, I
39:47 you never know. We, So what do we do? We
39:50 wait. Right. And then when appropriate, I mean, when we're
39:55 the age of two, we just of went whenever, but when it's
39:59 , we find our way to the and then we use the restroom to
40:03 rid of the the urine that was and stored in the bladder. So
40:07 purpose of the bladder is simply that store the urine until maturation. There
40:11 a couple of layers. The outer is referred to as the mucosa or
40:15 . This is the inner going inner outer. So mucosa is the inner
40:19 . It's basically a unique type of cell. These are called transitional epithelial
40:24 . Um it takes real time and to learn how to identify them under
40:28 microscope because they change shape. What do is they kind of look roundish
40:34 you have an empty bladder. But the lad bladder expands the cells themselves
40:38 out and flatten out. So they like a um uh like a squamous
40:44 cell. Um And I know that's helpful because you've all taken histology,
40:49 ? I'm just un teasing. I none of you have taken histology.
40:52 don't offer it. All right. The submucosa just sits underneath the mucosa
40:56 then we have a couple of layers muscles. So in this particular
40:59 we have three layers, there's just couple of tissues or a couple of
41:03 that have three layers of muscles. right. This just happens to be
41:07 of them. The uterus is another . Um And then outside that we
41:11 the advent tissue, which is just tissue to keep the bladder from ripping
41:14 as it fills up. It's basically tissue that prevents it from overstretching.
41:19 What's unique about the bladder is its at the base of the shape,
41:23 is not well shown here, but can see it more clearly here is
41:26 has a funnel shape at its So that means the lowest point is
41:31 , always, always at the So when the bladder fills up,
41:35 flows in and it goes to that point, it's not gonna collect in
41:38 pouch in a special spot or anything that. All right, you can
41:42 where the openings of the ureters So between the ureters and the
41:46 that would be what is referred to the trigone. And so it's basically
41:49 lowest point. So fluid flows in bladder fills up and then after the
41:55 fills up and it's time to What we're gonna do is we're gonna
41:58 urine through the urethra. The urethra two sphincters to it. All
42:04 The first sphincter is what is referred as the internal urethral sphincter. And
42:08 second one is the external urethral The internal, one is smooth
42:12 The external one is skeletal muscle. I control my smooth muscle? But
42:18 I control my skeletal muscle? So what we have here is we
42:23 two doors, two gates between the and the bladder, right? One
42:28 open on its own. The other you have control over. All
42:33 that's the idea here. So this the one when the bladder stretches,
42:39 internal urethral sin, the the bladder . And what it does is it
42:42 that muscle and causes it to And so that allows for urine to
42:48 through that point once you open up external urethral sphincter. So you go
42:54 the bathroom, right? You fill urgent class. So you head on
42:57 the bathroom, you go into the , you drop trout as the guys
43:01 say, I don't know what ladies , lift skirt, I don't
43:04 Um And then what would happen is do this right? I mean,
43:09 about it and what are you You're relaxing the external urethral sphincter.
43:18 right. So those two things have happen in order for you to actually
43:23 the fluid. All right. I mentioned this already. The female
43:28 is actually rather short and its sole is for the evacuation of urine from
43:33 bladder. The male urethra has multiple . It is not just a pathway
43:38 the bladder and the bathroom. It has. And you can't see in
43:42 picture on purpose, openings with the uh duct defines um the vast ephrine
43:49 which is part of the pathway for during the process of ejaculation, which
43:54 get to. In the third, last unit maturation is the fancy word
44:01 saying uh urination or avoiding. Those all the polite ways. You
44:07 peeing is the, I guess the year old way to say it.
44:12 There are two re reflexes involved, storage reflex and the maturation reflex.
44:17 , storage reflex, this is what doing when we're filling our bladder.
44:21 two things are going on. We sympathetic stimulation and we have somatic
44:25 Why do we need two different types stimulation? Two different types of
44:30 All right. So, with regard the sympathetic stimulation that is causing the
44:37 ? Huh? Yeah. The relaxation the detrusor muscles. All right.
44:43 what we're doing, the detrusor muscles the muscle name the named muscles of
44:46 bladder. And so what's happening is it's filling up, the sy sympathetic
44:51 is saying, keep relaxing, keep , keep relaxing and allowing your bladder
44:55 fill up. All right. The thing that it's gonna do is it's
44:59 continue to contract that internal sphincter. , remember, we don't want during
45:05 , we don't want uh urine to the bladder. So the sympathetic activity
45:10 allowing the bladder to expand, but also preventing that uh sphincter from relaxing
45:17 then the somatic stimulation, this is done through the pedal nerve. I'm
45:21 gonna ask you that it's not an class, but what you're doing is
45:24 clamping down and holding that external sphincter this. So, basically, you're
45:28 think of both doors are slammed shut I'm not letting anything out.
45:34 then it's time to pee. All . So, um, autonomic somatic
45:40 , I, is this the same ? Do I even bother racing stuff
45:44 the last night? I probably didn't . So this is the four
45:48 All right. First off, bladder gonna fill up roughly about 200 to
45:51 mils. All right. So we average it out, call it
45:55 So you fill up and what do get? All right. Well,
46:00 gonna get pressure inside that bladder. you're gonna detect that pressure that's sends
46:05 signal up to the pond. The says, hey, uh, let's
46:08 ahead and start contracting that, those, uh, detrusor muscles.
46:13 the detrusor muscles begin to contract because the expansion of the bladder. What's
46:18 in the eternal sphincter, it's beginning relax. And so you have two
46:22 going against you now, right? feel the pressure on the bladder and
46:27 have a sphincter that is opened But does urine come? No,
46:34 wouldn't it come? You have to the second step. Right. You
46:38 to open up the second door. , while you're sitting in class,
46:41 sat there and you drink your big of water. Right? And all
46:45 a sudden all that water has found way into the bladder. You hit
46:48 300 mark and all of a sudden feel that I gotta pee but you're
46:53 class and you're polite and you don't up and walk out. Right?
46:56 do you do? You sit there say go away, Pete, I'm
47:01 , it's not time yet. You even do a little bit of a
47:05 , right? And then what happens after about five minutes or so that
47:10 goes away and the bladder continues to . All right. So that's
47:15 If you ignore the reflex, it keep going on until you get about
47:21 200 or so down the line. then eventually what will happen if you
47:26 ignoring it is your body just says you. I know what's best for
47:30 and it will relax that muscle on own and then you will wet yourself
47:34 you will become an internet me, ? Or at least a photo that's
47:39 around amongst your friends at parties at times when it's most embarrassing to
47:44 All right. Either one works, in the absence of you blowing it
47:49 and you find your way into the , then that's when you're going to
47:54 the bladder. And in essence, you're doing is you are going to
47:58 that sphincter, that external sphincter. then because of the contractions of the
48:03 muscle, that's gonna press the urine of the bladder and out through the
48:10 today, you can go home and your parents, hey, I learned
48:14 to pee. They'll be so proud they're spending so much money on this
48:21 . Now, when you were a , most likely when you were a
48:28 , did your mother ever look you the eye before a trip and say
48:32 to the bathroom? Yeah. And went and what did you say to
48:37 ? I don't need to go. then what did she say? Get
48:41 that bathroom right now and go We're about to go on a long
48:43 trip just downtown because I know the we get in the car, what
48:46 you gonna need to do? You're need to pee. So what do
48:49 do? You go in the bathroom what do you do? You
48:53 All right. So how does that ? Well, it has to do
48:56 the abdominal pressure onto the bladder? . What you're doing is you're creating
49:01 , that pressure is detected by those receptors, which sends that signal up
49:05 the autonomic nervous system through the ponds down again and causes the contraction of
49:11 muscles. All right, that's all doing is you're forcing it to
49:15 So, it is a response that not, the bladder itself is not
49:21 . It's an autonomic response as a of the somatic pressures that you're putting
49:26 your bladder. All right. That sound like something you've done. Has
49:32 ever picked you up? And you , please stop squeezing me, you're
49:34 make me pee. No, I'm around the room, I'm su
49:39 it's had to have happened at least . All right, usually to women
49:45 don't admit to it, you Well, we don't get picked up
49:49 that often. But anyway, we have 30 minutes, 30 minutes
49:56 describe cause I don't feel like you have questions. You guys are just
50:01 at me like you should know. , go ahead. That. Why
50:08 it autonomic because of the sympathetic and governing the, the bladder itself?
50:13 , what we're doing is we're contracting , the, the sphincter,
50:18 But we're also relaxing through sympathetic So the counter of that would be
50:24 , causing contraction of that detrusor So that's what's actually causing the need
50:30 pee I mean, again, what you doing if I'm forcing myself to
50:34 . What I'm doing is I'm squeezing muscle that's pressing on the bladder and
50:39 it presses on the bladder, it that cycle. That is the normal
50:44 through the parasympathetic. That's why. it's autonomic that's doing the work.
50:49 not. You doing the work? . It's a good question. All
50:56 . Are we ready to deal with weird, the hard, I only
51:03 one person on their head. Ready. All right. First
51:09 where do you get your water Everyone thinks it's from my drink,
51:12 I also get it from my OK. Go squeeze a steak.
51:16 how much juice flows out of All right. There's water in
51:20 All right, you lose water through skin, you lose water through the
51:25 . You've seen that when it gets , breathe out, uh you lose
51:28 through the process of defecation, you it through urination. So there are
51:32 pathways. Water is lost from the . If your water levels get too
51:36 , no sweat. The kidney just filter, filter, filter water goes
51:39 and I get rid of that excess . We are designed to get rid
51:43 excess water. But if I become , I cannot draw water from the
51:52 . All right. Once I've made , remember what we said, it
51:55 be altered. So I have to mechanisms to draw the water in before
52:01 becomes actual urine. And the time becomes urine is after it passes through
52:06 collecting duct and enters into the renal into those kiss that we described
52:14 we are back at this picture of kidney and you can see where the
52:17 are and what this is trying to you is the osmolarity that I was
52:22 inside the kidney. So out here the cortex, you can see that
52:25 osmolarity is around 300 million osmoles. when you go into the medulla,
52:29 go from 300 down to 469 in milli osmos. And so you can
52:35 if this is my center point moving that center point, I've got this
52:39 that's moving from cortex down through the to create this very, very concentrated
52:46 . In other words, there's less more. So that's all that we're
52:49 here. I'm just using these terms just so that you remember. So
52:53 hypo hyper, just in case you realize what that means. Hypo too
52:58 water, hyper, too little All right. Now, if I
53:04 too much water in my body, all I'm gonna do is I'm just
53:08 allow the water to pass on right? But if I am
53:13 I want to reclaim that water before ever gets down into these yellow
53:19 And so what I can do is can reclaim that water and create urine
53:23 varying concentrations in other words, the that are gonna match this osmotic gradient
53:30 now and then I have a BME E taking this class. You know
53:32 A BME is, right? Biomedical . They look at this what we're
53:36 to describe and they go wow, is so cool for those of the
53:41 of the U universe. It's like is interesting. So here's our first
53:49 , the countercurrent multiplier. This is the loop of Henley is. And
53:53 that means, the countercurrent multiplier it has two aspects to it.
53:58 see if I can find my little thing. Uh Here's my draw
54:02 All right. So what we have is we have a loop that goes
54:05 and a loop that comes down or branch that goes up and a branch
54:08 comes down. So here we we're gonna move in. I'm just
54:12 sure I'm following it, right. there's our descending. So there's that
54:14 that, that is countercurrent. All . So the tubules are countercurrent to
54:20 other. I'm gonna point this out because it's gonna become important later.
54:24 notice the flow of the tubule look at the flow of the blood
54:31 the vasa is that countercurrent. So have a countercurrent system there as
54:38 So there's a lot of countercurrent countercurrent simply means the fluid is going one
54:43 it turns on itself and goes the way. All right. So the
54:48 countercurrent goes down, it reverses direction back up through the ascending limb.
54:53 descending to ascending the multiplier par part going to have to do with a
54:57 loop that is going to allow sodium come out and fill that area to
55:05 that and create that osmotic gradient. right. So this is what that
55:09 mallary Nephron is responsible for. All . Now that we're gonna look at
55:13 bunch of different pictures that are all be saying the same sort of
55:17 And I'm just trying to find one works for you. All right.
55:21 here we have the Juma Nephron, can see the med versus the
55:25 what the Jus Nephron does, it down deep. And so in doing
55:29 what we're gonna do is we're going make the flow of the fluid coming
55:32 with the osmolarity of that filtrate being like the rest of your body.
55:36 is the rest of your body? is its osmolarity 300 milli osm.
55:41 remember that number. It's gonna keep back to it. All right.
55:44 what it's going to do is that is now diving through an environment that
55:48 greater than 300. All right. then what it's going to do is
55:52 going to come back up and going move through that greater than 300.
55:56 on the other side, we're going have modified what that concentration of filtrate
56:02 inside that tube. And in the , we're also gonna slightly affect the
56:07 environment that we're gonna have to fix a result of this. All
56:11 So what we're gonna do is we're move materials out and we're gonna move
56:14 in and that is what is gonna us to establish that osmotic gradient.
56:19 then because we're moving things in and , that means we're also destroying at
56:24 same time. And so that's where vasa comes in and helps me to
56:27 things back into the right places so I can maintain it. And this
56:32 where it starts. All right. , I have here labeled descending lib
56:37 then I have ascending limb labeled, easier to start with the ascending
56:43 All right. So we're gonna deal the backside. Before we deal with
56:46 front side, the ascending limb is for allowing sodium and urea to move
56:56 the medulla of the renal cortex or the, of the kidney. All
57:01 . So there's two halves to We have the thick portion, which
57:06 the one that's nearest to distal convoluted . And what it does is it
57:10 pumps out sodium. So if I'm pumping out sodium, what I'm doing
57:16 I'm adding in a whole bunch of . And what does that salt
57:21 It attracts water, but the ascending is not permeable to water. So
57:28 water has to come from someplace or does it come from? Well,
57:33 here on the descending limb, the limb is permeable just to water.
57:41 when salt gets moved out, water on the other side. Now,
57:47 we're looking at in this picture is looking at a single nephron, a
57:51 is made up of hundreds of thousands nephrons. If you took a slice
57:54 it, it looks like a bunch Swiss cheese because you're looking at ascending
57:58 descending limbs and they're all next to other, right? This is just
58:02 cartoon to help you focus in on thing. So if I'm moving salt
58:07 of here, you can imagine right to it is an ascending limb that's
58:10 water to come out. So if is leaving out of here,
58:16 I'm gonna erase all the ink real . So here's my osmolarity 300.
58:21 water is leaving on the ascending what's happening to the osmolarity inside that
58:29 ? Is it becoming hypertonic or hypotonic ? So it's increasing in terms of
58:36 concentration as it's going down? All . So when it gets back down
58:41 , now, what we have is have a side that allows for salt
58:44 leave when salt leaves. What's happening the fluid on the inside becoming hypotonic
58:50 hypertonic hypotonic. So the salt is , pulling out water on the front
58:57 , but on the backside, I'm the salt back out. And what
59:01 up happening is I end up with fluid that has a much lower salt
59:09 . Or let me put it another . I'm creating a filtrate, which
59:15 hypotonic. I'm getting rid of excess . OK. So the first thing
59:21 the, the osmotic gradient does that creating is allows me to create a
59:27 that is very, very watery. natural state is to get rid of
59:36 . All right. Now, here's horrible, horrible slide. I'm gonna
59:42 right here and I'm gonna tell you now. So write this down.
59:46 on to youtube, look up osmotic formation and there's gonna be at least
59:52 dozen videos that will have an animation you can physically watch what's going on
59:58 so that you can match the fluid down the uh descending limb and the
60:04 moving up the ascending limb and the moving out and the water moving
60:07 So you can see it all working that what you'll be watching there is
60:12 these, this slide is basically telling is basically as a sodium leave and
60:17 water matches the water going down or filtrate going down is becoming more
60:22 But as it's going up, it's less concentrated. And over time,
60:25 it's doing is it's creating this osmotic on the outside. All right.
60:30 there's no good picture for me to you that and me coming up here
60:33 wiggling my arms around doesn't do a job. I used to show a
60:38 tiny video but it was a flash . And since flash is no longer
60:42 since 19 or 2018 or something like . Well, we can't show you
60:46 flash animations. It's easier for you go look it up. All
60:50 So go look one, go watch of the videos. It's like four
60:53 . All right. So now we this osmotic gradient. So out here
60:59 the side, you can see we an osmotic gradient that osmotic gradient is
61:03 result of the filtrate flowing through where is leaving where the water is
61:07 All right. Now, what we're with that filtrate is it's passing
61:13 out from the loop of Hindley up the distal convoluted tubule and then it
61:17 right down through the collecting duct and collecting duct passes through the osmotic
61:26 Now, I can use this to advantage. Now, the normal state
61:33 that the filtrate that I've created is far more dilute than when it
61:37 So I can get rid of excess , right? But in the event
61:42 my body is becoming dehydrated, I have something that I just stimulate.
61:48 . All I gotta do is open aquaporin and then water will go through
61:53 osmotic gradient and then out into that gradient, bringing water back into my
61:59 . And so I can create now very concentrated urine. So I can
62:08 the urine passing through or really the passing through. It's not urine yet
62:13 make something far more concentrated. And I have to do is introduce an
62:18 . And the way that I introduce is through vas suppressant, right?
62:24 the countercurrent multiplier is important because I off with a normal fluid that looks
62:31 the rest of my body. I it through the process and I create
62:37 that is dilute. And then I use that environment that I created to
62:45 a urine that stays dilute or becomes , very concentrated depending upon my
62:51 All right. So that's the And when I said this was
62:55 this is where my brain turned And I said, countercurrent and what
63:01 la la, la, la how many times did I do
63:04 Do you remember three times? Uh But we got this other
63:12 the vasa. All right. Do remember that picture that showed the blood
63:17 and the blood vessels went around the and across the base of the pyramid
63:20 then came back down and emptied, ? So let's imagine for a moment
63:26 peritubular capillaries instead of going around the capillaries and coming back up and then
63:31 around the outside and forming veins. , if they had just passed on
63:36 and just went right through that osmotic , what they would do is because
63:40 capillaries, you'd get capillary exchange and water would leave and salt would enter
63:45 . And I'd basically destroy the gradient I just spent a lot of effort
63:48 to build. And then I couldn't urine. That was a varying
63:54 So what the vasa does, it that problem. And what you do
63:59 remember, you go down and you're along the de the ascending loop because
64:04 they're next to each other. So going up, one's going down and
64:06 you come back the other direction uh to the ascending loop. And so
64:11 looks like this. And again, a capillary. So it's just going
64:15 exchange. So when I'm in a , very concentrated environment, what is
64:20 the capillary? So if the surrounding is hyperosmotic, what is leaving the
64:26 and into that osmotic gradient, what or salt water? And then as
64:32 move back up through the osmotic what is returning back to the osmotic
64:40 ? Salt? Right? And what's back into the tubule, the other
64:47 water? So what I'm doing is picking up salt where it was poorly
64:53 , moving it and putting it back it belongs. I'm taking water which
64:57 poorly deposited and moving it back to it belonged. So in essence,
65:02 I've destroyed environment by allowing water to in. I'm taking that water,
65:06 it someplace so that it reestablished the in its proper balance. So what
65:14 have is we have a countercurrent mechanism the loop of Henley that's creating the
65:18 . We have a vas Urrea that maintaining it. Because every time I
65:21 water and salt in and out of tubule, I'm actually not only
65:25 but I could also be destroying and what I'm trying to do.
65:29 in other words, let me come to this slide. When water is
65:38 over here, I am destroying That's what I'm trying to get
65:43 So what is a vas erecta It's picking up that water and moving
65:49 up here as an example? All , that's the maintenance part. That's
65:58 this is trying to demonstrate. This Vas Urrea here. OK. And
66:08 was the hardest thing we had to . The loop of Henley is responsible
66:14 creating the gradient. When that the collecting goes through, I destroy
66:22 . So the vas Urrea moves water salt back into its proper location so
66:27 your osmotic gradient is maintained so that can make concentrated urine or water,
66:35 , urine depending upon need. am I getting blinky lights? Because
66:42 getting late in the day? I blinky lights to eyes are like or
66:49 this not making sense or let's move ? Because reasons I've already told you
67:01 I first heard this, I didn't a lick of it. So if
67:04 sitting there going. I have no what you're talking about. You say
67:07 ? Nothing scary about that. Took three different times of taking this stupid
67:12 and I still didn't get it. had to teach it to understand
67:19 Yeah, I took it three Not that thing. No. So
67:28 loop of Henley is responsible for creating osmotic gradient. Right. That's the
67:34 part. Right? But when water through the collecting duct and the aqua
67:40 are open water is able to And so what that does is when
67:44 put water into a salty environment that it hypo osmotic relative to what it
67:49 . So I've just destroyed the osmotic that I created. So what does
67:53 vasa do? Because it's moving alongside loop of Hindley, it allows me
67:58 pick up that excess water or the if they're out of balance and re
68:04 uh kind of redistribute them within the . So that, that osmotic gradient
68:11 maintained. The other thing that it picks up the water and allows
68:14 to send it to the excuse me the rest of the body,
68:19 So that you can have the water your body and your body can use
68:24 , which is really the whole goal the first place. Did that make
68:32 sense? Yeah. Getting the half . The maybe if we ignore
68:49 it will go away. Looks, , when you really have bingo it's
69:04 , she said it better than You mean the capillary doesn't go straight
69:08 if it did it would wreck Yes, it goes down and it
69:11 back up so that it goes in out through the same path. Because
69:16 you become a vein, once you an artery, do you have any
69:19 of fluid exchange? No, which the vessels of exchange? Capillaries?
69:25 capillaries, always, always, always . So once I become a
69:29 I'm reestablished the structure. So nothing go in and out. So,
69:36 going on now? All right, at the collecting duct. We want
69:40 make water urine. All right. , that's the role of vasopressin.
69:45 right, vas suppressant acts on the com distal and uh convoluted tubule on
69:50 collecting tubules and the collecting ducts to uh say, hey, um right
69:55 you don't have aqua porns. They're sequester way on vesicles. What I
70:00 you to do is I want you make aqua porns and I want you
70:02 move those vesicles up to the And when doing so, what's gonna
70:05 is that now, water can now through those structures? All right.
70:12 water escapes through, then what you're do is you're gonna raise blood
70:15 So here is a VP uh without VP. So you can see here
70:19 go from 300 I become concentrated. worry about the numbers. I become
70:23 dilute and then when I pass I stay dilute. All right.
70:29 I sent me getting rid of excess when you drink a jug of
70:33 This is what's going on. But been outside in the Houston Sun all
70:37 long. You've been uh messing You haven't been drinking your water like
70:41 taught you right? So what happens your body says I need water and
70:47 fool is not getting me any. what I'm gonna do is I'm gonna
70:50 a vpavp comes along and it introduces aqua porn. So even though I
70:55 start off as a concentrate and I up as a dilute out here.
70:59 ends up happening is that water passes , that filtrate, passes through water
71:03 to escape. And so what I up with is a filtrate that is
71:07 concentrated, that is vasopressin role as function of that water increases blood
71:17 That's the easy way to think about . Now, sodium load is that
71:30 little thing that sits so far off the side. This is the one
71:33 we watch our salt because we don't have high blood pressure. All
71:38 So in the proximal convoluted tubule in loop of Henley, we already said
71:42 percentage of sodium is being reabsorbed. just a constant rate. It's over
71:47 the distal convoluted tubule where it's oh if I have low salt and
71:53 low salt would also be an indicator low water. Then what I need
71:59 do in order to bring in more is I need to pump in
72:03 And this is where aldosterone comes into . And what we use is we
72:07 this more complex system called the Renan and aldosterone system. Don't let the
72:13 scare you. It's not that All right. So where was Renan
72:20 ? Do you remember? And the someplace not the adrenal g it's in
72:27 kidney, it was in the I'll do this. Remember. What
72:36 I have? I had the afer , I had the eer arterial,
72:40 glomerulus and all the way around. then this is dis convoluted tubule.
72:43 structure where those two things are connected each other is called the juxtaglomerular
72:49 And so we had granular cells located the afer arterial. We had the
72:53 den C located with the distal convoluted , distal convoluted tubule, maloa cells
72:59 with the granular cells and say, , uh salt levels are low.
73:03 an indicator that we need more uh flowing through here. So I want
73:07 to go ahead and vasodilate. But I want you to start producing renin
73:11 Rennin gets released out into the blood it's an enzyme. And that Rennin's
73:17 is to break down a plasma protein in circulation in your body at all
73:24 . And that plasma protein is called . All Right. So this is
73:31 this thing is like. Oh, lots of stuff but where we
73:33 we're at the jury apparatus, we're renin. Renin acts on angiotensinogen causes
73:39 to be converted into a T angiotensin one and angiotensin one circulates into
73:48 parts of the body. And one the places it goes to is the
73:50 and inside the lungs, we have enzyme called angiotensin converting enzyme ace,
73:59 a cool name for such a boring and it converts A T one into
74:03 T two. Now, there's also A T three and an A T
74:07 , but we don't know what they . So we're just gonna ignore them
74:09 T two. Now is the important . It is the molecule of great
74:15 because it is responsible for a whole of things. One of the things
74:19 responsible for is to tell your adrenal . Hey, um we need you
74:24 start pumping salt into the body so water can come in. And so
74:27 causes uh the uh sodium potassium pumps be introduced into the distal convoluted
74:34 So I start pumping sodium into the convoluted tubule and wherever sodium goes water
74:42 . So, Doster plays an important of moving sodium into the body.
74:47 that water comes into the body and counters the low blood pressure as a
74:52 of the low water. Ok. . Well, what does that look
74:57 ? That's what it looks like So nice, simple model. Here
75:01 have the NGO 10 SYO converted into T one gets converted by ace into
75:06 T two. Tells aldosterone to come and says, hey uh stop,
75:11 stop secreting uh sodium reabsorb sodium. in doing so you bring in
75:17 So that's how you raise the blood . Oh That's not too bad.
75:21 else does it do? There's Yes, there's more. So A
75:26 two actually makes you thirsty. When am thirsty, I go grab a
75:32 of water and I drink my Glug, glug, glug water goes
75:35 my belly, belly into my What happens to my blood pressure?
75:40 goes up. So through drinking I increase my blood pressure. But
75:46 , there's more. It also stimulates . What now? Yeah. So
75:55 is reso is produced in response to produced in. Do you guys remember
76:01 it's produced posterior pituitary? Right? it's produced in response to the uh
76:08 two to act on the collecting the collecting tubal distal convoluted tubal,
76:13 the aquaporin. When I introduce What happens? Water goes back into
76:19 body. Do you see, is a common thing and all these things
76:21 bringing water into the body and then last one is, oh, by
76:24 way, it's also a vasoconstrictor, we learned about it being a
76:28 So if I make the space that's gonna raise the blood pressure.
76:32 RAAS is a blood pressure razor, its job and it does. So
76:39 increasing water fluid, you know, in the body, the volume of
76:43 in the body and reducing the space the blood vessels. Ok? If
76:50 want to see what all do and VP do in that loop, you
76:53 throw it all in there and you find where you are. So there
76:55 start with the ren and you can go through the whole thing. So
76:59 is um acting on thirst receptor. a VP acting on the kidneys,
77:04 yada yada. These are there just you to look at if you need
77:07 follow the bouncing ball. If I something on, what do I need
77:13 do? Turn it off. So have angiotensin aldosterone system in response to
77:19 . We have a NP atrial natural peptide. Very, very scary.
77:25 name for something very, very Atrial tells you where it's made.
77:28 is it made? Atria naic? My goodness. What a horrible word
77:33 from sodium na Naum, right? , have you ever wondered why sodium
77:40 the symbol in a It's Naum. right. Nice German word to confuse
77:45 . All right, etic urea So basically saying sodium in the urine
77:54 then peptide tells you it's a So what it does is it counters
77:59 and it does. So simply by just making sure I'm saying this
78:02 Yes, inhibiting renin and aldosterone So if I block renin, that
78:08 I brought block A T two. I block a 22, I block
78:12 production. And oh, by the , why don't we just go ahead
78:14 bypass those early steps and let's just aldosterone production by itself. And so
78:19 doing so, I'm basically tipping it other direction. So instead of reabsorbing
78:24 , what do I do is I those aqua porns. I'm no longer
78:28 . I'm not bringing water in and just going to let it pass on
78:31 and I can get rid of all excess water. And so what you're
78:34 now is you're playing a balancing game these two systems, ras and A
78:39 are just sitting there doing this all long trying to make sure I'm maintaining
78:44 blood pressure and ensuring I have the water salt balance in the body.
78:49 right. The other thing that it is the dilation of the Glom Afer
78:55 . Remember I was constricting them in first place to increase the pressure uh
78:59 drive uh fluid in. So that's we're doing. Yeah. Last little
79:06 seemed like there were a lot of for this class, but a lot
79:09 them are just like just click, , click. All right. These
79:12 just some simple statements, statements, ? So in the tubular segments that
79:16 permeable to water. So, reabsorption always always accompanied by comparable water
79:22 Want that in English wherever sodium goes follows. Secondly, solute excretion is
79:29 accompanied by a comparable water excretion. what that's saying is if I allow
79:33 to stay in the, in my , then the water is gonna stay
79:37 there. And so it's going to going to be lost. That's all
79:41 saying. All right. So if is a loss or if there is
79:45 gain of pure water that is not by a so deficit or excess,
79:53 , then that's gonna change your ECF . That seems really dumb to say
79:59 loud when I, when I say that way, in essence, if
80:02 add in extra water, it affects molarity. That's all it's saying.
80:06 right. Now, here's an if I drink pure water, what
80:11 I have to pee because I now excess water in my body because my
80:15 has become hyper osmotic or hypo right? The second part. If
80:23 drink too much alcohol, none of have ever done that. Have
80:28 OK? I didn't think so. that's gonna do? Alcohol is an
80:32 of vasopressin. And when I inhibit , I no longer put those aquaporin
80:36 place. And when I don't have aquaporin in place, that water leaves
80:39 body? So what happens to me I drink alcohol? I become
80:45 Right? And that's never happened to of us ever. Right. None
80:49 us has ever had a hangover. hangover is a function of dehydration.
80:59 . Just letting you know. there you go. That, that's
81:02 kidney. Everything from here on out sailing. It is straightforward when you're
81:10 with the kidney. What do we ? One end to the other
81:14 And you're good to go that one two too too. How do you
81:24 good. I got your emails. . Maybe. Let me see.
81:36 trying to remember. What am I at? I look at a calendar
81:38 Monday next week I want that. want that. I'm going to be
81:46 a committee meeting all day long. . Mhm. Friday. This Friday
81:58 think so. What time there? in my office? I work.
82:09 right. I'm, I'm putting it . Ok. Actually I'm gonna put
82:13 over here. How was today? huh. Yes. Like, like
82:18 types of alcohol that are good
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