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00:04 All right, y'all. So what we're gonna do is we're gonna

00:09 in with the um the kidney and gonna continue with the process of how

00:16 making urine from the filtrate from the . All right. So remember what

00:22 were talking about on Tuesday, we about making the filtrate. And so

00:26 did we do? We took the plasma came through the aar arterial into

00:31 Gloria and then there was the pressure the glomeruli was strong enough or hard

00:39 or the net filtration pressure was strong to push fluid through the poto sites

00:46 through the epithelium and through that layer base membrane and get fluid into the

00:53 is called Bowman's capsule. OK. so now what we're going to do

00:59 we're going to take that fluid, has everything in it that was in

01:03 plasma except for the large stuff, ? So we don't have blood

01:09 we don't have large proteins, but have all this material in there that

01:13 the body wants and the body wants get rid of. So it's water

01:18 stuff minus the plasma proteins. And the next two steps that we're going

01:23 be looking at, looking at are re absorption and secretion. All

01:27 there's two different steps and they're going be occurring concurrently. And so what

01:32 going to do is we're taking the , which is step one, the

01:36 and we're now going to go through process of reabsorption and secretion. Now

01:42 do this, what we're going to to do is we're going to have

01:44 move materials from the tubule back into blood. And to do that,

01:49 means materials are going to have to through the cells that make up the

01:53 of the tubule, right? So have remember the proximal convoluted tubule,

01:58 have the loop of Henley and then also have the distal convoluted tubule before

02:02 get to the collecting duct or there's a collecting tubule in the collecting

02:06 . All right. And so the that materials move, and this is

02:10 a reminder is you can either move cells or you can move through

02:14 And so if you're moving between we refer to that as I should

02:17 turn this on is referred to as transport. So some materials will do

02:25 . They will, they will find way in between the cells move through

02:28 tight junctions and find their way out the, from the tubule back into

02:34 interstitial fluid. And then they'll work way back into the blood, other

02:39 can't do that. And so they to go pass through the cells through

02:42 process of what is called trans cellular , which means they go in through

02:47 tubular cell and then out through the side and if that's going to

02:50 you're going to need to have some of transport mechanism to allow that to

02:56 . Right. And so you should flashing back right now and thinking,

02:58 my goodness, he's going all the back to a MP one into that

03:02 unit for you took a P one we're starting to talk about those molecules

03:07 . And the answer is, that's kind of why we keep coming

03:11 to all this stuff. All So that's really what we're looking at

03:14 is we're going to be looking at through both those membranes and having the

03:20 materials there to allow for that movement occur. All right. So the

03:26 processes ire that we're gonna be looking absorption secretion. So to have this

03:34 , there needs to be something that or draws the materials one way or

03:38 other, right? And what we're do is we're gonna, I'm

03:42 we're gonna kind of walk through a of them and then I'm gonna tell

03:45 a little bit easy way to remember because it's something that I think we're

03:50 kind of familiar with that has nothing do with the kidney. All

03:54 But the idea here is we have have, if we're moving water,

03:58 gonna be a colloid pressure that's pulling towards where there's more colloid. You

04:04 what colloid means? It just means , right? So, where I

04:09 colloid, that means there's more stuff than there is water. And so

04:12 an osmotic gradient that draws water to the colloid is and it's just a

04:17 word for saying stuff. All So that's probably one of the ways

04:21 going to happen. So if you this higher solute con concentration, water

04:27 to where there's a higher solute con . And as a result of that

04:32 moving, there's going to be a flow of other materials because wherever there's

04:38 water solute follows. Does that kind make sense? All right now,

04:44 I said, I've got a little for you. Hopefully we'll pull it

04:47 together. All right. So what tubular reabsorption? What is tubular secretion

04:54 is the process by which the body back to it or the kidney returns

04:59 to the body, the things which wants or needs. All right,

05:04 talked about glucose, for example. right, glucose is something that your

05:08 doesn't want to get rid of it energy unprocessed, right? And you

05:14 hard to get that. Now you're hard is different than most organisms.

05:18 don't have to sit there and wait ambush like a mouse, right?

05:23 don't have to chase down a You just have to get on your

05:27 and doordash something. Right. So work is a little bit different but

05:31 still energy that's expended and energy that received and you don't want to just

05:36 away energy right in other word. me put it another way. If

05:41 had a pocket full of money and reached in and the money fell on

05:44 ground, would you just look at go? That's too much work to

05:46 pick that stuff up. No, would go and grab that. Even

05:50 it's a penny, you're like, my penny, right? And that's

05:53 of the same thing is that your is saying that is stuff that I

05:57 need and I don't want to get of it. It needs to come

06:01 . And so that's what Rebs is do, right? So anything that

06:06 body wants, it's gonna get, you don't have a reabsorptive ability to

06:10 something in, then your body doesn't need it. Ok? The last

06:15 is, um, uh, oh , the amount needed is gonna be

06:23 a function of those, that property I just said that, you

06:27 it has to do with your hydration and the presence of that material.

06:31 right. And so, for there are some things that your body

06:35 reabsorb, but if it already has much of it. It's not going

06:38 reabsorb it because it's got to follow rules by which reabsorption occurs. All

06:44 . And so really what we're talking about is water and ions. And

06:49 we'll get to that in just a . All right. Now, couple

06:54 things, the rate at which you transport something is going to be

06:57 It's gonna be dependent upon how many these channels or carriers that you have

07:03 . Which kind of makes sense. I'm looking around the room and I

07:07 walking in, how many doors do have in this room? There's 1212

07:14 then there's four in the back if think about it, right? So

07:18 many people can move in and out this room at any given time?

07:21 rate if each door represents one person per attempt. So we can move

07:28 people out and anything beyond that you're to start running into trouble,

07:33 So the rate at which we can people out is going to be based

07:37 how many doors we have. So we want to increase the rate at

07:39 we move people out of this what do we have to do?

07:42 have to add more doors. All . So transport ma maximum is the

07:48 fastest rate at which you can move from the tubular fluid out into that

07:54 space. It's how quickly we can that material. The renal threshold is

08:00 how much can be carried in the . Um Or let's see,

08:05 the point where you start exceeding the maximum. So, um for

08:14 um there is a finite amount of that you can have in your

08:20 All right. So glucose, like said, is an energy that we

08:25 hasn't been processed yet. But if are diabetic, for example, you

08:30 put glucose into your cells as well you should. And so what ends

08:36 happening is that the blood glucose levels to rise and rise and rise and

08:40 and eventually what happens is, is rate at which we re absorb that

08:46 is superseded by the amount that's found the blood. And so it stays

08:51 the urine. You know, the way how they used to discover and

08:55 out if you had diabetes. That's . Actually, they would, they

09:00 check the urine and it's even grosser that because the doctor would stick his

09:04 into the urine and taste the And if the urine was sweet,

09:11 had sugar in your uh in your and that's how they knew it.

09:16 Doesn't medicine sound fun now. just wait. All right. So

09:22 , that is the what when we about renal threshold, it's basically that

09:26 where the process of moving materials back the blood is exceeded by the amount

09:32 already in the blood. So you can't filter it fast enough. I

09:35 , it's being filtered but you're not it fast enough. All right.

09:39 , threshold maximum is the rate, fastest rate, which you can reabsored

09:44 amount that's in the blood. So just stays in the urine. All

09:51 . So what type of substances we ? Well, we have some,

09:55 substances that are going to be completely . All right, under normal

09:59 we're not talking pathologies. So these things that you don't find in the

10:03 normally. All right. Um So is typically the, the reabsorption is

10:08 to take place in the proximal convoluted . So it's kind of this easy

10:12 is remember what we said is when look at this, at the

10:15 it's a tube. And so you say, well, what's going

10:17 Well, filtration is taking place at front end of the tube. That's

10:21 Bowman's capsule between the gloss and Boman . So when I go in the

10:26 convoluted tubule, that's the first place we're going to start seeing reabsorption and

10:31 is going to be a whole bunch different things. But we have some

10:34 that are going to be completely And typically these are those things that

10:38 nutrients and those things which are plasma that have escaped through. All

10:42 And these would be very, very ones. So, in terms of

10:45 , we're talking about glucose. We're about amino acids, we're talking about

10:48 sugars like lactate. Um These things small and your body wants them.

10:53 in order to get them back in body, there has to be some

10:56 of transport mechanism that picks it up the filtrate and says you go back

11:01 the interstitial fluid so that you can back to the blood. And this

11:05 also going to be true for the plasm proteins. Um The difference

11:09 is we don't have um carriers because things are a little bit larger.

11:14 you're going to use a process of . So again, you just,

11:19 have receptors or you're taking samples of the filtrate, taking into a

11:24 , the vesicle moves around goes and it go off on the other side

11:28 the cell. All right. what's gonna usually happen is you're gonna

11:33 up those little tiny proteins and well, I, I'm not gonna

11:38 the actual protein. What I'm gonna is I'm gonna break it down.

11:41 so you get more amino acids and can make more of the plasma

11:45 but I'm not gonna let them leak because that is something that I can

11:48 to build other things or I can for energy. You do know amino

11:53 we use for energy, right? , ketones bodies. All right,

11:57 worry about them. All right. how do we do the uh

12:03 Well, most of the time, we're using is a co transport

12:06 All right. And again, this way back to a MP one way

12:09 at the beginning of the semester. we talked about these co transporters where

12:14 have sodium and what sort of nutrients interested in binding together. So the

12:19 wants to be in the cell down concentration gradient, glucose or amino acids

12:26 go into the cell because there's too of it. So there's no no

12:29 other than by expending energy. So use a co transport which is secondary

12:35 transport, meaning it doesn't use energy . So they bind to a receptor

12:40 the same time or a carrier at same time when both of them are

12:44 , then that carrier changes shape sodium in the glucose goes in or the

12:49 goes in and the amino acid goes . All right. And then on

12:53 other side, we may have a that allows that material to leak out

12:56 the cell down its concentration gradient. then sodium needs to be pumped to

13:01 to the other side. All So that's where the energy comes from

13:05 from that pump on the other All right. So from moving from

13:11 loin lommen refers to the inside of kidney. That's how we get into

13:14 tubular cell. And from the tubular , it's that passive process. All

13:20 . Again, I'm gonna make this simpler in just a moment. I

13:25 . Ok. And this is about it's gonna happen. All right.

13:34 then there's other things that we're going reabsorb, lots and lots of

13:37 So here's just kind of a partial . Water is something that we're going

13:40 reabsorb, but these things are gonna absorbed through a regulated process. In

13:45 words, it's gonna be based on . So if we have a lot

13:48 salt in our body, we're not to absorb all the salt. All

13:51 , if we have too much we're not going to re absorb all

13:54 water because that doesn't make sense. body wants to get rid of some

13:58 these things depending upon the conditions that in our body at any particular given

14:03 , right? So there's going to regulated mechanisms and the key thing in

14:07 of this is this statement right This last little bit, right?

14:12 is the thing that plays a major or a pivotal role in the reabsorption

14:18 all the substances. Are you ready the time out ready for the story

14:23 help you understand all this stuff. guys remember high school and high school

14:28 . Yeah. Do you remember That one cool gal. That one

14:32 girl. She's some of you might of her as the mean girl.

14:35 of you might have been that right? And she had the perfect

14:40 and the perfect boyfriend and the perfect were always walking around the high school

14:44 hands, doing everything together. Do you remember them? Right.

14:48 one went, the other one Whatever class one took, the other

14:51 did whatever, anything they did was coolest thing ever. So everyone hung

14:55 with them and so they had their , didn't they? And there was

14:59 of them, usually the guy, guy who was the friend in,

15:04 in the friend zone with the right? And you all knew who

15:07 was because you're like, dude, never gonna hook up with her.

15:11 he was there, he was there that girl just in case the bad

15:15 that guy broke up because he really right for the the the guy was

15:21 . But she had all her girlfriends followed along. And so it was

15:25 grand group of people and movies have written about this stuff, but every

15:30 school had something like this. Are all familiar with this idea? All

15:37 . Sodium is that girl? Is that guy that he's hooked up

15:44 that's hooked up with that girl. sodium goes water follows who wants to

15:49 up with sodium? It's an easy . Chlorine, right? Sodium and

15:58 man, they, they match, perfect for each other, right?

16:01 no, no, no sodium when is around dissociates and wants to hang

16:04 with water. So wherever sodium you know, water is gonna naturally

16:08 . And then because of osmotic chlorine is gonna follow because,

16:13 I got to hang out with the . I gotta hang now with

16:16 So it's gonna follow. And whenever goes someplace what you've done now is

16:21 created an osmotic gradient that drives the of all the other stuff,

16:26 So if water goes, there's more over here than there was before.

16:29 potassium goes, there's more water over . Bicarbonate goes, there's more water

16:33 here. Calcium goes, you name ion, it follows water. Do

16:38 see the process here? So, this is the statement you need to

16:43 ingrain in your brain wherever sodium water falls, wherever water goes,

16:48 else falls based on osmotic considerations. But doctor Wayne, you said glucose

16:53 sodium move together. That's right because is the cool girl and who wants

16:59 hang out with the cool girl? . So glucose moves with sodium amino

17:05 , move with sodium, right? moves based on those two things really

17:12 on sodium. But it's wherever sodium water follows. OK. That was

17:17 end of the lecture. Go That's basically what the rest of this

17:21 is all about. If you understand concept. Sodium in water. I

17:25 . Let's see if people actually get . We're gonna see if this is

17:29 , right? But if you understand soda goes, water follows. Then

17:33 we gotta do is figure out where is going and then we're going to

17:36 where everything else moves. All this is the beauty of kind of

17:41 that step back and looking at the picture rather than trying to memorize a

17:44 bunch of little tiny things because we see stuff like this. So where

17:49 sodium reabsorbed? Where does sodium It's a regulated molecule. So it

17:53 some place. Now, I want to think about all the sodium in

17:56 body. All right, the stuff in the blood that's circulating around,

18:00 ? It's going to be filtered. of that sodium, if 100% of

18:04 sodium is being filtered, 65% of is reabsorbed back through the proximal convoluted

18:11 . All right. So you can here why reabsorption is such a big

18:15 at the proximal convoluted tu because so of the sodium that is being filtered

18:20 the through the filtrate is is moving into the body. All right.

18:25 so these are the ones where we , hey, when we're talking about

18:29 of all the other stuff, this where it's happening. So sodium goes

18:34 falls wherever water goes because of osmotic , all the other stuff go.

18:39 that doesn't mean all of the sodium being absorbed here. You can see

18:42 here on the slide that that filtrate down through the loop of Henley and

18:46 the loop of Henley, 25% of stuff is being followed. And this

18:50 the part that plays a major role the concentration of your urine. And

18:55 going to spend the last half of class talking about this and how the

18:59 of Henley works. All right. then A small portion of your

19:06 about 10% is going to be reabsorbed the distal convoluted tubule in a highly

19:12 fashion. You've probably heard at some in your life that salt is bad

19:17 . You don't eat salt. It you high blood pressure. Have you

19:20 that? Right? It, it's not 100% true. There is

19:24 relationship and we've just figured out what relationship is. You mean wherever sodium

19:28 , water follows. Yes, that true. But what we have is

19:33 we call a sodium load in our . So that's not the, uh

19:38 the amount of salt you put in body. So, only 10% of

19:42 salt that goes in your body is to be regulated in this fashion and

19:45 that role in blood pressure. The 90% is there being reabsorbed naturally And

19:56 playing a role in adjusting your urine . So it's only that small,

20:02 10% that plays a role in, being regulated to determine whether or not

20:08 need to put salt in your body you need to excrete it into your

20:13 or secrete it into the, into filtrate. So it can be excreted

20:16 with the urine. OK. disco tubule is the regulated stuff.

20:22 right. So you can see it there regulating extracellular fluid volume when you

20:28 that or see that you should think pressure. Ok. So very,

20:32 small portion and that's based on your . So, if I have too

20:37 salt in my body, my body to get rid of it, but

20:40 wants to maintain a certain amount of in the body for the other

20:46 All right. Now, how does get absorbed? All right.

20:50 in the prom convoluted tubule, we channels. All right. That's kind

20:54 easy. So I've got channels that me to move down my concentration

21:00 So remember I try to keep low inside cells. So sodium moves from

21:04 channel or from the loin and from filtrate through the channel into the

21:08 And then on the other side, have a pump that sits there and

21:11 sodium, I want you out of cell. So it pumps it out

21:13 the um into the interstitial fluid, will then find its way to the

21:19 . And at the same time, pumping in potassium and so the potassium

21:24 going into the cell and I'm going be able to use that for other

21:27 as well. All right. So is how I'm moving sodium. The

21:31 way I'm moving sodium is I have cot transporters. I got sodium glucose

21:36 . I got sodium amino acid And so because of that low concentration

21:41 the cell, sodium wants to go and it brings along its partner glucose

21:46 the amino acids. And that's how move the glucose and amino acids back

21:51 the body. So the movement is this direction. All right, that's

21:58 I'm getting sodium reabsorbed. Now in distal convoluted tubule. This is that

22:04 . So notice I'm skipping over the of Hindley right now. All

22:08 because I want to put that all . So here, the more salt

22:12 put in your body, the more goes into your body, the less

22:16 you have in your body, the the water stays in the filtrate.

22:20 . So far you're all with right? OK. If the water

22:23 staying in the filtrate, that means peeing it out. That means your

22:26 is more water like. But when become dehydrated, what does your body

22:32 ? It wants the water. It want you to go and find

22:36 It already has water. I just want to let it go out into

22:39 bathroom. And so what your body is it uses hormones to adjust how

22:46 water is going. So one, things I can introduce pota sodium potassium

22:53 into the cells. In which now I'm pumping sodium back into the

22:59 , right? And wherever sodium goes follows. All right. So that's

23:04 way. And how do I do ? Well, that's gonna be through

23:09 . Aldosterone is a hormone that's produced the adrenal cortex, which we'll get

23:14 a little bit later. And what does, it says, hey,

23:19 over here in the distal convoluted I want you to put those channels

23:22 those pumps in place. So we move the sodium and then the water

23:25 follow in. And so what happens I move sodium into the body and

23:29 means the water is going to And that means I'm retaining water rather

23:33 letting it leave my body. The hormones at atrial retic peptide. This

23:39 the opposite effect. What it does it blocks or inhibits Aldo release.

23:44 I block that release, then sodium going to stay in the filtrate.

23:50 because sodium stays in the filtrate, stays in the filtrate and water leaves

23:54 body. Now, we've already learned these two hormones when we talked about

23:58 A A S when we talked about pressure. All right. So how

24:02 were cause blood pressure to go up Aldo and blood pressure to go down

24:07 by altering the water in which way going, is it going to the

24:12 or is it being removed or allowed enter back into circulation. So you

24:20 how there's a connection between all these . OK. So far so good

24:26 sodium reabsorption. I like the one . Yeah. Yeah, I got

24:30 . Wherever sodium goes waterfall is. mark. That's telling you you got

24:35 you're good to go. All OK. If you ever forget,

24:38 like, oh my goodness, I . OK. They just got to

24:40 of that one little thing and then rest of it should kind of fall

24:43 place. All right. Well, about water rebs sop? Well,

24:48 already said wherever sodium goes water So this is going to be osmotic

24:53 if I increase my solute out in interstitial space and in the blood water

24:59 going to move from the filtrate to interstitial fluid in the blood.

25:04 how do I increase my solute Well, it follows sodium. That's

25:08 solute. All right. So here pathway can be through the, between

25:16 cells. But the way to get moving really, really quickly is to

25:20 aquaporin, which are just fancy water . All right. They actually play

25:25 kinds of roles in the body. the primary role aquaporin even tells you

25:29 the name aqua water pourin. Ho I N is protein. So it's

25:34 water hole or a water channel. , in the proximal convoluted tubule,

25:39 aqua pons are always there and they're available so that water can follow the

25:43 in the distal convoluted tubule. We describe what happens. We pump,

25:48 the pumps in place. So the goes right. But if water can't

25:52 , we need to introduce aqua And so here we're gonna introduce um

25:56 uh aqua pons because of a different that suppress in which goes with by

26:02 name is anti diuretic hormone. All . And all this does is,

26:07 says, hey, I'm going to the aqua porns in place when it's

26:10 and when a DH is not I'm gonna remove the aqua porns.

26:14 water is either going to be able leak out of the, out of

26:17 filtrate or it's going to stay in filtrate depending upon the needs. So

26:23 , Aldora and Ad are working in to allow for water to move with

26:31 . These terms, you may see water reabsorption, facultative water re

26:37 It just refers to the presence of aquaporin. Obligatory means I'm obliged to

26:44 , right? If you're obliged to something, what does it mean?

26:47 have to do it? All So wherever sodium goes, water naturally

26:51 . So if I have an I have to follow, I'm obliged

26:56 do so. Facultative means there is facilitation, I'm being allowed to

27:03 OK. And so in this this will be the distal convoluted tubule

27:08 water, wants to follow salt, it can't do so unless I put

27:12 aquaporin in place. OK. So when you see those terms, that's

27:17 it means. So, proximal convoluted , obligatory facultative in the distal convoluted

27:28 . So just as a reminder, is vasopressin, it is antidiuretic

27:34 Um I won't go there. Um basically when you have low water in

27:39 blood. In other words, as levels rise and your water level is

27:43 , that's going to stimulate the production vas supress. It's stimulated in the

27:48 and it's released from the anterior or posterior pituitary gland, not the anterior

27:55 . And then it goes in And what it does is it introduces

27:59 binds to those tubular cells and causes porns. Two things aquaporin to be

28:05 to the surface because they're already there bound up to two. So

28:11 it's like you don't have to wait them to be made, they're already

28:13 . You're just telling the cell put in so that you can start moving

28:17 . And then it will also tell cell, hey, start producing more

28:20 these. So that, that's basically effect. All right. Now,

28:28 slide can be kind of confusing and not saying that it is confused.

28:31 just kind of because there's two things are being stated in this slide.

28:35 talking about reabsorption and secretion on this . All right. So it says

28:42 , secrete. So where it says , that means I'm secreting, what

28:46 secretion which direction if reabsorption goes into blood secretion would be going out back

28:53 the filtrate. OK. So when dealing with a potassium, potassium is

29:00 in different directions depending upon where you . So, in the proximal convoluted

29:05 , you're doing reabsorption. All you're following water. So where sodium

29:09 , water follows wherever water goes, other ions are following as well.

29:13 right, proximal convolute tubules easy. right, when you get down to

29:18 nephronic loop, you're still reabsorbing. . So we're just, so you're

29:23 again, we're, we're dealing with a bit. But when you get

29:27 here to the distal convoluted tubule and get to the collecting tubules. Now

29:31 dealing with secretion. Ok? So I am reabsorbing sodium, I am

29:39 either a channel in the distal convoluted or I am introducing in response to

29:46 sodium, potassium pumps, sodium is reabsorbed but potassium is being secreted based

29:55 those pumps. Ok. So in presence of aldosterone, I'm increasing the

30:01 of potassium secretion. Ok. So just one of those little things you

30:07 to understand if I understand mechanism, understand direction. So just a convoluted

30:14 aldosterone introduces sodium. Potassium A T S pumps, sodium is being

30:20 So water can follow, but potassium being secreted as a result of that

30:26 . All right. Now, this happening inside the type A inter or

30:31 sorry, it's not in the inter , they're constantly reabsorbing. So,

30:36 we're doing is we're modifying reabsorption by aldosterone. We're now secreting more than

30:45 are reabsorbing. But generally speaking, direction does sodium go or?

30:53 Potassium go. It follows water. does calcium go? It should follow

31:02 . What does phosphate do? It follow water. All right.

31:07 generally speaking, what we're doing here we're, what we're, what we're

31:11 is um calcium and phosphate is primarily up as a salt in your

31:18 So for those of you who took MP one, remember we spend all

31:21 time talking about bones, bones, and how they're not dead tissue that

31:25 play a role as being a calcium . And the way that we make

31:28 salts is calcium and phosphate. And when we need to circulate calcium,

31:33 break down bones and that means we're release both calcium and phosphate together and

31:37 stay disassociated in the blood. when you circulate that blood through the

31:44 , 6% of that calcium is going be filtered and about 90 95% of

31:48 phosphate is going to be filtered and wants to come together and hang out

31:52 they're attracted to each other and they salts and that's not a good

31:56 Um What we want to do really is we want to keep the calcium

32:00 the body because we can get phosphate anywhere. Phosphate, everything we eat

32:04 phosphate in it, right? Anything has nucleic acid, which means everything

32:09 consume phosphate, right? So, is an easy thing to access.

32:15 . Seems a lot harder to come . How many of you guys like

32:17 eat bones? No. Uh, here like to eat seashells. How

32:23 of you guys take calcium supplements, in your vitamins when you eat your

32:27 ? Yeah. So that's where your comes from, ground up bones and

32:31 , from seashells. Hm. It's , you don't know it because it's

32:36 washed and ground down in a little and you don't know better. All

32:40 . But that's where it comes Calcium is, that's an easy access

32:45 . And if you weren't getting it that, you'd be getting it from

32:48 , that's the other place we get from. You know, when you

32:50 of chalk, not the, the you write with before it's processed to

32:54 stuff you write with, it's taken of the ground and then it's isolated

32:58 compressed into a little tiny, little that we write with. Hm.

33:05 that calcium is valuable, right? makes strong bones. So we want

33:11 hold on to that. And so have a hormone, we'll probably talk

33:15 this a little bit later when we about the endocrine system and it's parathyroid

33:21 . I may not talk about it because I'm talking about it now.

33:24 right, parathyroid hormone comes from a tiny uh structure called the parathyroid

33:33 which is found on the back of thyroid or where's my thyroid?

33:37 the thyroid is this butterfly or bow looking gland that sits right here and

33:42 see this big old structures like that's big. Well, what is

33:45 parathyroid while you flip it around? like four little dots, one on

33:48 wing of the butterfly. And it's , OK, that's the parathyroid and

33:53 job is to help us to re calcium. And so one of the

33:59 that it acts is here on the and what it does, it

34:03 hey, um let's start reabsorbing calcium here in the distal convoluted tubule.

34:10 that puts calcium in the body which that we so that we can retain

34:14 . But the other thing that it , it says, hey, um

34:16 can go ahead and let that phosphate because I'll be able to get some

34:20 from my diet just simply eating I can get phosphate. And that's

34:25 of weird sounding but it's true. right. So this is how we

34:32 the calcium in our blood. There's that's one of three ways. And

34:37 when we talk about calcium regulation, is one of the three ways that

34:42 do that. So before I go , does this movement or regulation of

34:54 make sense wherever sodium goes water All right. And then I've got

35:02 things that can regulate and kind of that, but calcium moves back in

35:06 body. Not because of anything other that water has moved there.

35:11 I'm allowing it because of the presence the, uh, the parathyroid

35:16 All right. That makes sense. . It naturally wants to be reabsorbed

35:22 in the distal convoluted tubule where I a secretion mechanism. All right.

35:27 , the little exceptions are the things you have to understand. Now,

35:33 don't like to spend a lot of talking about uh buffering. Um because

35:38 buffering system is, is a little complex. It deals with the

35:41 it deals with the lungs. Have ever just sighed randomly? Just,

35:48 you done that? Yeah, that's of the buffering system that's removing carbon

35:53 so that you move more carbon, moving more carbon dioxide out. And

35:58 do that, I have to convert back into carbon dioxide. Remember we

36:03 about that when we talked about the , right? So that's part of

36:07 system. And I said we're not talk about that. All right.

36:10 bicarbonate is one of the major buffers the body. It actually out numbers

36:16 number of protons, something like 60 1. And so every time you

36:20 another proton on the blood, it shifts the P H towards um uh

36:29 . All right. So by carbonate the most part can be freely filtered

36:34 we have so much of it, just kind of there. And so

36:36 can kind of get rid of And that's one of the other ways

36:39 get rid of carbon dioxide. All . But protons primarily stay in the

36:45 . All right. So where do see this reabsorption? Most of it's

36:48 to be done in the proximal convoluted . So, if I asked you

36:51 question right now or this was a I had, what role does the

36:55 convoluted tubule play in the kidney? would you say it plays a

36:58 What would you, what do you the answer is gonna be absorption and

37:02 you're, you're starting to see. , great. All right. There's

37:07 that's gonna be reabsorbed in the nephronic . All right. But you can

37:11 of see that we're really dealing with um uh this idea of we're going

37:16 reabsorb materials uh through these two Now, what we, we absorb

37:23 what we secrete is gonna be dependent the state in which our blood is

37:27 found. All right. So when blood is more acidic than normal,

37:33 typically, this will happen if you a high diet in proteins. All

37:38 , because proteins basically uh shed off protons pretty easily. This is when

37:44 type a interrelated cells become very We said a for acid, that's

37:48 , really easy. And so what gonna do is we're gonna take those

37:52 and we're gonna start shedding them off out of the body. All

37:56 So the protons are picked up, use a pump system to do

38:00 and what you're doing is you take proton, you move it out and

38:04 any of the bicarbonate, you're going actually move back into the cell and

38:07 it. And so in doing so getting rid of the acid and you're

38:11 base back into the blood. Pretty . When you're talking about an alkaline

38:17 right here, you're just going to the opposite and it's the type

38:21 all right. So what they do they pick up protons and they're

38:24 OK, I'm gonna, instead of protons staying in the filtrate, what

38:27 gonna do is I'm gonna move them into the blood and I'm gonna pick

38:30 bicarbonate and I'm gonna shed it and it into the filtrate so I can

38:34 pee it on out. And so is how your body, the other

38:38 , one of the other mechanisms that body uses to maintain proper P H

38:42 the blood. That's basically all I to say about it. I don't

38:47 to make it any more complicated than . And like I said, the

38:51 play a major role as well and a lot more to it than

38:55 But I want you to understand those types of cells is that pretty

39:00 A for acid B for base. do the A cells turn on when

39:04 P H drops? When do my cells turn on when my P H

39:09 ? OK. And if that didn't sense P H, when it

39:13 it's acidic. Ready for the Weird you guys have a slow friend,

39:23 know that person that you can tell joke to and they stare at you

39:26 about 20 minutes and then they start . Yeah. Ok. That's your

39:32 right. So, in that big of friends, right? We got

39:35 cool girl. We got the cool , we got their friends, we

39:38 the, the, the guy in friend zone and then they also got

39:42 guy, right? The slow you know, still part of the

39:48 in, in, in all the . He's like the jock, the

39:51 jock. That's like dumber than a of rocks, you know, but

39:54 really big and he's the one that his head through the windows. And

39:59 right. You guys didn't watch the movie. So, you know,

40:01 didn't get revenge of the nerds and you're better off dead and stuff

40:05 that. Oh, I've got a if you need a bunch of movies

40:09 watch. All right. So is that. Now we get rid of

40:16 waste. Uh We have, nitrogenous waste exists in like three different

40:21 , right? And today I can the third one and I thought I

40:24 it on Tuesday, but I wasn't far off. All right. So

40:28 have urea, urea is what happens we break down proteins. And so

40:32 is a byproduct of amino acid metabolism protein metabolism, right? So,

40:38 your liver is doing and then you uric acid, uric acid is breaking

40:44 DNA and RNA molecules. So when you get down to those nitrogenous

40:49 , that's how you're getting rid of that nitrogen, nitrogenous waste through

40:55 nucleic acids. And the third type muscle metabolism, muscles use creatine.

41:02 then when you break it down, becomes craine. And that's the nitrogen

41:05 . That's how we, we take and we get rid of that as

41:08 . So those are the three ways we get rid of it, but

41:10 want to focus in on the first . Urea. All right.

41:14 when I said urea is slow, I mean is, is that its

41:17 of reabsorption is slower than the rate reabsorption of the other material. If

41:22 took a sample of your body, , any of the fluids, we'd

41:26 that you have urea throughout your entire all the time. All right.

41:30 it, it, it plays a in determining your os um your osmolarity

41:37 your body. So, just like salt everywhere, there's urea everywhere,

41:41 we're trying to get rid of It's not something we want to have

41:44 up because it can be dangerous or to us. But, because we

41:49 it in this form of urea, actually a lot safer than say

41:53 Would you agree with that? Ammonia pretty nasty stuff. Yeah. All

41:57 . So, this is what we're is we're using that. Now,

42:01 stuff is freely filtered and so when , when the blood passes through,

42:05 picking up the same portion. So portion of the uria that's passing through

42:11 filtrate or in the blood is coming the filtrate, but then it's being

42:15 and it's about 50% of the filtrate the urea that's in the filtrate is

42:20 to be reabsorbed. So let's just I had 10 molecules of your ear

42:23 pass from the blood to the Then through, in the proximal convoluted

42:28 , five of them go back into body and then your body says,

42:33 a second. Um um I'm trying get rid of this stuff. And

42:36 what it does is it picks up , that five and it moves it

42:41 in, in the loop of Henley , get rid of all this

42:44 So when the flu filtrate is going through the loop of Henle, I'm

42:48 up to 100% of the filtered. now I have 10 molecules back in

42:53 as an example. But then because osmotic considerations, urea is still trying

42:58 go back into the body. And again, it slowly moves back

43:04 Now, while we don't filter 100% the urea or, or secret or

43:12 me, excrete 100% of the, urea that we filtered. We're still

43:17 rid of excess urea. So by time you get down here to the

43:22 duct, You've reabsorbed 50%, So if you started off with 100%

43:29 to 50%, you're back to you're still getting rid of 50% of

43:34 Urea. And so you're getting rid excess stuff. But it's because it's

43:41 being attracted to the water that's returning into the body, it's moving with

43:48 . So it's a little bit It's not 100%, but it's good

43:53 does that makes sense. OK? it's not the only one there.

43:58 acid and Craine are doing similar but it's not like is, is

44:04 and that's why we bring it Ok. So we've covered a lot

44:11 different things, right? But we sum it up in that one little

44:18 wherever sodium goes, water follows and else kind of goes with that.

44:23 there's some things that we want to rid of faster than, than the

44:30 filtration process. And this is where comes into place. And so what

44:35 have is we have a system that's more complex than we're going to explain

44:43 in essence, what it is is the proximal convoluted tubule. There are

44:47 molecules that recognize metabolites of different processes get rid of things that we don't

44:56 around. All right. So let just try to explain this using

45:00 for example, or not like not , drugs, bad drugs, shame

45:05 you drugs, but like medications. right. How have you guys taken

45:12 ? If you take two ibuprofen? the next time you can take two

45:17 ? Six hours? You'll understand why , I'm, I'm, I'm,

45:22 pointing at you. All right. who's taking acetaminophen? That's Tylenol.

45:28 often can you take? You take two acetaminophen? When can you take

45:32 next two acetaminophen? Four hours? important. Ok? If you're taking

45:40 leave, when's the next time you take on a leave? This is

45:45 fun 1, 12 hours, And then there's some drugs where it's

45:52 you can only take them once a . All right. The reason for

45:57 is going to be something that we're to look at in just a moment

45:59 the plasma clear. It's the rate which I can get rid of a

46:03 from my body. Now, the if we didn't have a process of

46:09 , the way that we'd get rid the substance that would be filtered and

46:12 presume there's no reabsorption, then we'd to wait for the blood to keep

46:17 through our body and it would just a little bit at a time until

46:20 eventually got away. Right. for example, using those three

46:25 which are all pain medications, Aleve, Ibuprofen, Mefin. I

46:31 even know what the name for Aleve . I usually have some pre farm

46:35 . Oh, yeah, the name blah, blah, blah,

46:36 And I'm like, ok, I never remember the way these things

46:42 . The reason that you can take you have these different times is because

46:47 rate at which your body gets rid them is different. And it's because

46:51 the secretion method here, right? these aren't just being filtered. They

46:55 these carriers that are looking for the and they are capable of binding up

47:00 metabolite and then picking them up from blood and moving them in. So

47:04 rate at which you're removing them is , much faster. And there's all

47:09 of these. And that's what this down here below is just showing some

47:12 the ones that we've identified. So are unique carriers for each of these

47:16 ions because the metabolites are ionic in nature, they either positively or negatively

47:21 . And so they're easily recognizable. so the carrier grabs them and move

47:25 , moves them across the membrane, ? So without these, the rate

47:30 removal would take longer. So let's of things that are bad for our

47:35 , right? Because the metabolites. of drugs is not, not that

47:39 of a deal. But let's say put a toxin in your body,

47:42 enough to kill you, but enough , you know, kind of make

47:45 ill, right? And if you had a filtration mechanism, then your

47:50 would be exposed to that for as as it took for it to filter

47:54 . And that means it would have circulate. So let's just say each

47:57 it passes by 50% of it right? So that means if you

48:03 off with 100%, the first time blood filters, through you lose half

48:07 the next time, however long it about five minutes, then you'd lose

48:11 half and then another half and then half. And you can imagine over

48:15 , it would take many, many before you finally got rid of it

48:19 a secretion system like this. What can do is say, all

48:22 maybe I'm only losing half during but maybe through the secretion method secretion

48:28 , I'm losing the other 50%. it only takes one route for all

48:33 the material to be removed from your . This is how we get rid

48:38 metabolites from like hormones, right? your body doesn't want those signaling molecules

48:44 around forever because they can turn on in inappropriate ways. So your body

48:50 in there like I don't want to rid of this as fast as I

48:53 . So this is the way we increase the rate of, of of

48:58 of materials that the body doesn't want through things like this, through the

49:05 . And again, that's, that's extent of it because like I

49:08 there are so many different types of involved here, separate types of

49:14 But the key thing here is materials that we put in our

49:18 the metabolites, metabolic waste that our is breaking down different molecules and even

49:25 hormones. You guys know what E T is good on you. I'm

49:36 . And the people who do are there going, I'm not gonna say

49:38 word E P T is a brand for the early pregnancy test. E

49:46 T. That's its name, You pee on the stick, you

49:50 out if you're pregnant and they you can find out within four days

49:56 , of, of uh basically uh . How do, how,

50:02 how, how does this work? are you measuring a hormone in the

50:08 ? Right. And really what it is not necessarily the hormone, the

50:11 has to be broken down. And what they're looking for is the

50:15 And how is that metabolite? Easily ? Well, because of the rate

50:18 secretion because of stuff like that. just an example. Anyone here ever

50:24 to take a drug test? Isn't that fun? Right. Get

50:28 job pee in the cup. Um, you know, before a

50:34 test you are never, ever, , ever, ever to go have

50:37 seed bagels or poppy seed muffins. you know why? Where do poppies

50:44 from or where do poppy seeds come ? Poppies? Where does heroin come

50:49 ? Poppies? And the metabolites appear same on the drug tests?

50:55 don't eat the poppy seeds before the test or you'll have to take it

51:01 over again. So if you're trying mask something, well, I'm not

51:05 say anything but again, same It's these types of mechanisms. All

51:14 . Are we good so far we with any questions about how we move

51:21 ? No, because I said at very beginning, wherever sodium goes water

51:28 , I could have let you guys . See, I told you,

51:30 said you could leave. I want talk now about the one thing that

51:37 I was in your seat where I it the first time and then put

51:41 fingers in my ears and said, la la, this is too

51:45 I'm not gonna learn this. And year that I took an anatomy course

51:49 physiology course, I did the same . And then once I had to

51:54 , I realized how easy it So wanna deal with urine concentration and

52:00 osmotic gradient. All right. Now all aware and I've, we've talked

52:04 this, that urine has varying concentrations upon your state of hydration,

52:10 So the more water you drink the , your pee is, the less

52:14 you drink and you become dehydrated, more concentrated it becomes, we're all

52:17 with that concept, right? So order for that to happen, that

52:22 we have to move water into the or leave it in the filtrate.

52:26 right. That's, that's the principle we're dealing with. And so the

52:29 is how does that happen? All . So the first thing I have

52:32 here on the slide is to point what our bla bla our blood osmolarity

52:37 relative to the interstitial fluid relative to cortex of the kidney. And I've

52:42 told you that we say that the of isotonic, the state of,

52:48 , of, of Materials in that is around 300 million osmoles. So

52:54 you match 300 million osmos, you're , which means that there is no

52:59 gradient which water doesn't move. It's happy wherever it is. So the

53:04 in your brain, the fluid in blood, the fluid everywhere in your

53:08 , that's the same osmolarity. So doesn't move into a particular direction because

53:14 osmotic considerations. But we've been talking osmotic considerations for quite some time

53:21 right? And the reason is because have channels and we have pumps that

53:25 moving salt. And so water moves response to energy usage because a salt

53:32 moving, but that's expensive, Energy wise, it's very expensive.

53:38 we want to create a system that use more energy than we're already

53:43 OK. That's the idea here. , if a fluid is hypotonic,

53:49 that's saying is that you have uh solute than normal. And so that

53:55 you have more water. So water gonna move away from that area.

53:57 if you're something as hypotonic, then extra solute. So water is gonna

54:02 towards that area, right? So you see those terms, it's easy

54:07 get confused. So just think hyper is more, is less and

54:11 And then tonic refers to solute. right. So that allows you to

54:15 , OK, if I have less , that means I have more

54:18 If I have more solute, that I have less water. All

54:22 Now, in order for us to water to move one way or the

54:27 , then we need to have that in osmolarity, we need to have

54:30 hypertonic or a hypertonic state. We want isotonic, we want to have

54:35 difference so that the water moves to it needs to go. All

54:39 So this is what that osmotic gradient I referred to has. And this

54:43 kind of shows that here out in cortex, you can see the 300

54:46 can see the value is going down 1203 100 down to 1200 all the

54:50 around. All right. And so osmotic gradient is what allows us to

54:55 water because the area around the tubule specifically the collecting tubule and the area

55:04 the loop of Henley has a different concentration. And so whenever I have

55:09 different solute concentration, wherever there is water follows. OK. So that's

55:15 we're looking at. All right. it's this, that allows us to

55:21 the concentration of our urine. how do we go about doing

55:26 Well, it's because first off, nephrotic loop is a countercurrent multiplier.

55:31 you can see that here in this here over here would be where Bowman's

55:35 is. So here I go, go down and then I go back

55:38 , that's countercurrent one direction, then other direction. And you can see

55:43 , I'm going to go back down more time. So countercurrent first to

55:48 flow of the fluid inside the it's going down and then it's coming

55:51 up again. That's the descending and ascending loop, the multiplier refers to

55:57 feedback mechanism that's going to allow us concentrate out the fluid first and then

56:05 the concentration second. So what we're do is we're gonna move salt and

56:10 gonna move water so that the filtrate its osmolarity as it passes through.

56:16 , this was happening as a result not the loop of Hindley through the

56:20 nephrons, but through the jua medullary , the ones that go down deep

56:24 come back up. So this is all this is actually taking place.

56:29 so what he said is that the of Henley is responsible for creating

56:32 this osmolarity difference, right, this gradient. And so how it works

56:38 a, in a very basic nutshell I'm gonna first focus over here.

56:43 right. So along the lengths of a sending loop is you have a

56:49 bunch of sodium pumps and the sodium are sitting there taking sodium from the

56:53 and pumping it out into the And so wherever sodium goes water

57:03 But on the ascending side, we not have aquaporin. So water can't

57:08 on that side. But on the loop, we have aquaporin. Now

57:15 things are right next to each other so, right, so if I'm

57:19 salt on this side, then water gonna be leaving on this side.

57:24 right, they're that close together even the picture doesn't look like that.

57:28 salt is leaving, making the filtrate and less concentrated on this side.

57:35 water is leaving, making the filtrate and more concentrated. And as the

57:40 leaves and comes out here, the environment becomes more and more concentrated and

57:47 the water leaving out helps dilute it some. And so what we end

57:51 with is in the deepest parts, is where we're going to have the

57:55 concentrations and in the shallowest parts nearest surface, that's where we're going to

58:00 the least concentrated. Now, this a really, really difficult concept and

58:08 really hard to see in a static like this. And so I think

58:12 have a video that's posted like after , if you want to see the

58:17 , you can kind of watch the to see what's going on. All

58:20 , but I'm not so interested in understanding every single solitary step along the

58:25 here. I just want you to what we're trying to do is we're

58:29 a mechanism to move salt to cause to move. That creates this environment

58:34 we're going to take advantage of. right, it's the environment that's

58:40 And then as the fluid is passing , it goes down, it starts

58:44 at about the same os malaria as body 300 it gets really, really

58:48 around 1200. But then as it back up, it becomes really,

58:52 dilute about 100 million osmoles. So urine that you're making, you

58:58 or the filtrate as it as it's through becomes more and more watery as

59:02 goes through. So your natural state to get rid of excess water.

59:09 . So your filtrate is extra watery to start off with. And if

59:13 else happened, then that filtrate would on through and out, it would

59:17 as extra watery urine. OK. you're not always over hydrated,

59:26 We need to make adjustments and look what the collecting duct does. It

59:32 through that same osmotic gradient that you created. So that's how it's

59:37 That's what the osmotic gradient does. that's what this slide is basically talking

59:42 . It's allowing you to create this . So that when the fluid passes

59:48 on its way out through the collecting , what I can do is depending

59:52 my need. If I'm, if dehydrated, I start producing vasopressin.

59:58 the vasopressin we said, introduces aqua into the collecting duct. And if

60:03 put aqua porns in the collecting there's extra salt out here. And

60:07 what's going to happen is the water the filtrate and now I'm making

60:11 very concentrated urine and it was I didn't expend any extra energy to

60:19 that happen. OK? If I'm dehydrated, vain, vain isn't

60:26 So the urine that I make is because I've made a very, very

60:32 filtrate. Now, we talked about vas erecta. Those are those long

60:41 layers that go alongside the loop of . Why do I care about the

60:46 erecta? Great. It's just one thing for me to memorize. All

60:50 . Well, every time water what does it do to the osmotic

60:55 ? Right? If water is leaving And water is passing out here and

61:03 is passing out there. What I'm is I'm making micro adjustments to that

61:09 . And so as we introduce more more water, I'm actually destroying the

61:15 gradient that I created. But a which is carrying blood that starts off

61:22 300 million osmos passes through there. so it lets water out and salt

61:27 in and it redistributes the water and salt. And so when you go

61:32 into a deeper concentrations, water but when you go back up

61:37 salt leaves and picks up water. that's where the redistribution comes along.

61:43 so while I'm making the gradient, also destroying it. But because the

61:48 is there, I pick up the that are destroying things and I redistribute

61:52 back to where they need to And so the osmotic gradient is

61:58 So we have a system that works a passive way to ensure that this

62:04 so that you can pee extra water expending any extra energy. That's the

62:11 purpose of this. Now, this is hard to see,

62:18 If I show you that picture I'll start there looking at that

62:23 Can you figure out what that Yeah, I mean, I don't

62:28 . No, I'm I'm with So if you want to understand how

62:33 doing it, watch the video that gonna post on blackboard. If you're

62:39 interested in knowing how like what are the steps. But you really,

62:43 key thing here is, oh I creating a vari a variable concentration on

62:51 outside. And I'm using that to water because you've already learned the

62:58 And so if I'm hydrated, I to get rid of water. So

63:03 not using the surrounding environment. It's there. But if I'm dehydrated,

63:10 can put in aqua pons and it draw water out of the, out

63:14 the filtrate so I can make something concentrated that a little bit easier.

63:26 . Are there questions? Like no , I'm not gonna ask a question

63:31 something like that. Fast question makes feel dumb. You wanna get

63:40 don't you? I mean more slides got Like 5, 3-5. I

63:47 we're almost done. Oh, there a question. Thank you. Get

63:56 of some excess vitamins. Mhm But some other vitamins I was like,

64:03 didn't quite to actually vitamin C gets too. It's just that much,

64:12 higher concentrations. So the question is , why can I uh have certain

64:18 and I can just kind of pee the stuff, right? The the

64:21 is it has to do with the sort of thing. We're gonna

64:24 really kind of, that's kind of the next thing is, is is

64:28 , plasma clearance. How fast do get rid of stuff? So every

64:32 in your body has a a specific it wants to maintain selenium. Do

64:37 ever think about your selenium? Do you ever think about your

64:41 No. Anyone anyone here ever bother think about how much selenium your body

64:45 . How about, how about the of zinc your body needs? That's

64:48 mineral, right? Ladies usually think iron for the most part guys tend

64:54 hold their iron a little bit right? But I mean, there's

64:58 sorts of calcium, you know, in your body has a specific concentration

65:03 can maintain and it will get rid the excess. But like thing like

65:08 vitamin C, you, you don't bother thinking about what that concentration

65:11 You start getting the toxic levels around mg. So if you like if

65:18 like me, you know, the C pills back in the day,

65:22 are they? They're basically sweet they're orange flavored sweet tarts. You

65:25 pop them. I'm the only one ever did that. It's like 600

65:33 don't do, don't do more than . All right, because that's when

65:36 body can't get rid of. And what we're talking about, its ability

65:39 get rid of it. It's like reached plasma thresholds and that's the

65:44 So your body does still get rid it. It just does so more

65:48 it wants to hold on iron specifically there's a lot of reasons to have

65:53 iron in. But your threshold, much iron you could have? It's

65:57 , oh, well, there's too and so it will start shedding

65:59 It's not, it's just not necessarily the urine primarily through feces.

66:07 I know we don't want to talk poop right now. But what's the

66:10 color of poop brown? And that's Billy Reuben, remember? So,

66:15 , it's from the hem and the . What was the other one that

66:20 asked about? It was another, vitamin, you said vitamin C,

66:24 E, vitamin K is another We don't actually consume a lot of

66:28 K. Um Here's a fun I mean, you guys, you

66:31 watch Big Bang, right? Did ever watch Big Bang Theory?

66:36 I mean, Jim Jim Parsons is U H alum. That's Sheldon,

66:42 ? There's a scene where he and penny go shopping and they're at

66:46 grocery store and she's picking out vitamins she's like picking out. He

66:51 oh, you don't want to buy . That's basically you're just um you're

66:55 just gonna pee it right out, ? And she see, she

66:59 well, maybe that's what I wanna . And then he says because he

67:02 all the chemical property, well, , maybe, then what you want

67:05 manganese because the amount of manganese in body is so low. It's kind

67:08 like selenium, you need it, it's very, very small.

67:20 So aqua porns, generally speaking. in an open state. But in

67:24 we're talking about the uh the cells the collecting ducts. So these are

67:29 principal cells, aqua porns are actually away. So there's vesicles that are

67:36 to the uh cell membrane and then away from the cell membrane. And

67:41 basically are are accumulations of the So what aldosterone does or assumably what

67:48 supress does is it's a signal that two things. The first thing it

67:52 , it says, hey, uh vesicles where you have all the aquaporin

67:56 to go ahead and move them to surface. And so that way you

67:59 the aquaporin so that they can be . But the other thing that it

68:02 , it tells the cell to make aquaporin. But notice, I don't

68:05 to wait for them to be They're already there. I just have

68:08 shift them to a place where they actually be functional. So it's kind

68:13 cool. Yeah. OK. Abs see that one, that one.

68:24 . Which right. So what this the question she's asking is, I've

68:34 this really weird statement down here. concentration increases from 1200 mil osmos to

68:39 . What this is referring to is concentration of the filtrate itself. All

68:45 . And so if you think about filtrate, just follow the arrows

68:48 what's going on is I'm starting the filtrate looks like rest of the

68:51 at 300 mil osmoles. But because the pumping that's going on over here

68:56 the fluid goes down, water So I start off at 300.

69:00 the inside of that tube becomes more more concentrated. So when I get

69:04 here, I'm matching the surrounding environment 1200 Miasmas right now, that's a

69:09 of the salt pump out over there that the water will fall over

69:14 All right. But as the so now I'm down here, so

69:17 1200 million osmoles, as that fluid back up, remember, it's going

69:23 and salt is being pumped away from and it's a constant rate at which

69:26 being pumped. So as you're traveling up, that filtrate inside, Because

69:32 salt is leaving goes from 1200 and passes, passes past it and it

69:37 beyond 300, it goes to And so by the time you get

69:43 out here into the cortex in the convoluted tubule, you're now more watery

69:49 you started off with. All Now, that concept, that idea

69:54 , is a little bit kind of , wow, that's a lot.

69:57 a lot going on there. But I've done here is using a mechanism

70:01 I can take advantage of. I'm two things first, I'm creating an

70:05 that I'm gonna take advantage of. . That's number one. And then

70:08 two is I've made urine or really , that's water more watery than it

70:15 when I started. So I went 300 to 100. But in doing

70:20 , I had to pass through AAA of concentration before I became more

70:27 So that's what's going on. And what that statement refers to anyone

70:34 10 minutes to go through the last slides. G F R G F

70:42 is the GME filtration rate. We've talked about the rate at which the

70:46 is formed per unit time. It's your doctor uses to determine your kidney

70:52 when you go to the doctor and take your blood and they go make

70:55 pee in the cup. What they is they're looking for two different elements

70:59 and they're basically using a formula that has been well established to kind

71:03 determine whether or not your kidneys are correctly. All right. Now,

71:09 there are real issues, what they'll is they'll inject you with this uh

71:13 sugar. It's called inulin, not . It's inulin. And what inulin

71:17 , is a, it's a plant and it can't be broken down and

71:20 can be filtered and so it can't reabsorbed, it can't be secreted.

71:24 they can measure it and they just look at what is its concentration in

71:28 urine, what's it, concentration of plasma and what's the volume of urine

71:32 you've collected? And so they can that to calculate it out. What

71:35 real, your true G F R is as opposed to the calculated one

71:40 they give you just by taking your and taking um your urine. Because

71:44 that no one's ever given you any when you've gone to the doctor.

71:47 right. So if you have a G F R, that's an indicator

71:54 decreased kidney function. And so the that we normally evaluate how kidney is

72:01 is through this G F R. really what we're asking is is what

72:05 the renal plasma clearance rate? remember we just talked a moment ago

72:10 three different drugs, right? And talked about the the rate at which

72:15 things are removed from the body. in six hours, you can take

72:21 because the rate at which you're removing from your body takes about six hours

72:26 that you're, you're uh clearing Is there anyone who takes them?

72:30 don't wanna know the medication but anyone take a medication like daily, just

72:34 , right? So just so you , you're not going from uh you

72:38 , taking your drug and you're going and then it's leaching down to

72:42 So you take, take your drug , right? What's happening is is

72:46 you take it on a regular the rate of clearance allows you to

72:50 . So you take it up 100% it doesn't go down to zero,

72:53 goes down to let's say 25%. the next time you take it,

72:56 now at 100 and 25 now you down to 50. And what ends

73:00 happening is you then have over a of a couple of days reach a

73:04 where you now are saturated in that and the body is not able to

73:10 it. That's plasma clearance. plasma clearance is a weird way of

73:16 things. I'm not gonna pretend that makes any sense to normal humans.

73:21 . What it is is the volume plasma cleared of a particular substance per

73:27 . So what we're doing is we're the volume, not the amount that's

73:31 the in the volume. So let's you have 100 mg of something in

73:34 blood. They're not asking you, long did it take you to remove

73:36 100 mg? They're asking you how , how much volume is passed to

73:44 that substance which is backwards if you me, but no one asks me

73:49 it's not my math. OK. substance has a different plasma clearance

73:55 ibuprofen every six hours, acetaminophen every hours, Aleve every 12 hours.

74:03 what this does is it demonstrates how we can remove or how, what

74:08 body's ability is to remove that substance itself. Now, the last little

74:13 here that's, that's key about this when you look at a substance,

74:16 can kind of look at it and these questions like, all right,

74:20 I'm trying to look at a is it moving, is it or

74:24 faster or slower than the G F ? So for example, if a

74:30 is not going to be reabsorbed and it's not going to be secreted,

74:35 the rate at which I'm removing it the rate at which I can filter

74:38 if that makes sense. So that's that has a plasma clearance rate equal

74:43 the G F R. So inulin one of these types of substances.

74:48 right, that's why they give it you because they know it's neither reabsorbed

74:52 is it secreted. So the rate which it's passing through this is

74:55 this is your G F R. then we have substances that are

75:00 These are the things that your body , right? And so what you're

75:04 for is something if, when you're at a substance, you're asking the

75:08 , is it being reabsorbed completely or it staying in the filtrate? So

75:13 have things that are complete like the body desperately wants to keep the

75:18 . So its plasma clearance is right? You do not ever get

75:24 of it except under pathological conditions, urea has a partial plasma clearance,

75:33 ? It's partially reabsorbed. So there a plasma clearance, but it's less

75:37 the G F R. So if F R is here, urea would

75:40 down here zero. Would we be over here? And then we have

75:45 we want to secrete. So these the medications, these are protons,

75:48 example, they're not going to be . Instead, they're both filtered and

75:53 . So when you take your your body is not going well,

75:56 want to keep some of that. just saying I want to get rid

75:59 this. And so its plasma clearance going to be greater than the G

76:04 R. All right. And so you look at a drug and they're

76:10 you take it this often, don't it more than this. It's because

76:16 dealing with, if you take it than this, you can't clear it

76:19 enough. So you start building up levels of that material. Ok.

76:28 little bit, I guarantee you none this will be on the test because

76:35 , so you can start packing yourself , right? Basically, there are

76:38 of urine, it's sterile, it's water plus stuff in it. You

76:45 about 1 - two L per Think about how often you go to

76:51 bathroom, right? I mean, you can count it up,

76:55 You wake up in the morning probably morning right after lunch, mid

77:00 right after dinner, probably one more before you go to bed, maybe

77:05 before you go to bed. And pee out anywhere between 254 100 mils

77:10 the math there. Six times 400 six times 22 50. You'll find

77:18 in those numbers. If you drink water, what's gonna happen, you're

77:23 pee more. There you go. that's not hard. P range is

77:27 4.5 and eight. You're averaging around . Remember we said diet affects this

77:31 little bit here. It's heavier than . Does that make sense that it's

77:35 than water? So specific gravity is greater than water. So when you

77:40 in the toilet notice that the urine filters downward, right? It's really

77:46 solutes that are in there. Color from clear to some really strange and

77:50 things depending upon the concentration of the in. That's why you get those

77:55 colors. If you're interested to see colors, what they mean. Some

78:01 these are the fun ones like red , beets and blueberries, you can

78:06 red when I was in high I went to a boarding school and

78:09 of the things we did was we a hold of methylene blue. We

78:13 it in the Kool Aid. One drank like, I don't know,

78:17 10 glasses of Kool Aid and then peed blue food die. So

78:25 he freaked out. It was Um Turbidity is clear but it can

78:31 cloudy. Um uh because of certain and lastly a smell there, the

78:38 smell is called rino. Like I'm , you're annoyed. So you're

78:44 That's the smell of fresh urine. you have weird smells, that can

78:49 indicate pathologies. Asparagus is not a . That's just your inability to break

78:55 a spare gene. So some of recognize that when we eat asparagus,

79:00 smell the urine smells terrible. Some you are like, I don't know

79:03 you're talking about. That means you break down a spare jean. The

79:07 of us can't and you'll know. anyway, um I want you guys

79:12 have a fun spring break. Remember only assignment you have is to read

79:18 remember you can read starting on Sunday , after spring break. So you

79:23 , go have fun, stay Don't do stupid

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