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BIOL 2302 Human Anatomy & Physiology II - 2302_lecture12_0307
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00:03 Good morning campers. You guys never that. Did you? Yeah.
00:11 . All right. Um, so couple of things, uh, we
00:14 about, uh, eight people that still taking the exam. So I'm
00:17 gonna open it up until Thursday maybe Friday morning, depending on what
00:22 clock lets me do. Um, not gonna show, uh, grades
00:26 , or stuff probably until after, , spring break because I want their
00:30 in there. I want you guys really understand what those grades are.
00:33 so I kind of want to just of focus in on the kidney for
00:37 next two days, which is really to do because how many of you
00:40 are really here? I mean, not here. I, I'm,
00:43 brain's already in spring break. Is brain already in spring break?
00:47 It's like, been like the early semester, I think in a
00:51 time. I mean, that's probably true but it's just like,
00:54 man. And so I'm just going let you know, now, you
00:57 , the stuff that we're going to is not, like, scary
01:01 but because our brains aren't necessarily it's going to make it harder to
01:06 through that stuff and then we get break and we're going to forget everything
01:09 learn and then we're going to come and we're going to be expected to
01:11 the stuff that we lost. So aware of that as you are moving
01:15 notice, I have no requirement, expectation that you guys are gonna study
01:19 spring break. Right? You I know there are some professors
01:22 oh spring break that just means I to pile on more work.
01:25 no, no, no spring break for breaking. So for this
01:30 at least just know that you have to uh resell yourself because when we
01:35 back, we gotta come back All right. And what we're gonna
01:40 doing uh over this unit is we're two sections. One that can be
01:44 little bit kind of confusing. I'll be honest when I was in
01:47 seats, when I did the there's this part of the kidney where
01:50 like, I don't know. And I started doing this every time I'd
01:53 it, I'd go like la la, la la, I don't
01:55 to know and then the second so I'm going to try to walk
01:59 through that to make it easy, ? So it's not as hard as
02:03 could be. All right, but just one little section of it and
02:06 everything after that little section is As far as I'm concerned, moving
02:10 the end of the semester, digestive easy. And what we're doing when
02:16 think about the kidney, the digestive , we're going to deal with the
02:19 reproductive system. Each of these systems tube systems. And what I mean
02:24 that is that there is a beginning the tube and there is an end
02:27 the tube. And when you have tube system, that means when you
02:31 it, you can treat it by through the tube and asking the
02:35 what goes on during the tube? happens here at the front end?
02:39 other words, an example would be , think of a car wash on
02:42 front end of the car wash, put in a dirty car at the
02:45 end of the car wash, you a clean car. So what are
02:48 steps to go from dirty car to car? All right. So when
02:52 studying these things, the kidney, digestive system and the reproductive systems of
02:58 there are two, right? Ask question, hey, this is a
03:02 . Where do I start? Or start at the front end of the
03:06 and I work through the tube and find out what happens by the time
03:09 get to the back end of the . If you do that, it's
03:11 to be pretty easy. It's an way of organizing. Information. And
03:15 what we're gonna do for the first talks is we're gonna talk about the
03:18 today. We're doing kidney anatomy. right. Uh We're, we're doing
03:23 urinary system, but we're going to kind of focus in on kidney anatomy
03:26 . And then we're going to deal some of the processes, really the
03:31 of filtration that the kidney is responsible . It's one of three major processes
03:35 allow us to produce urine. And on Thursday, we'll deal with the
03:39 two processes and then we'll talk about . All right. So our starting
03:44 here is just this, this is urinary system and a big, you
03:46 , for the big picture stuff. should pause. Are there questions first
03:51 the, the test stuff? You ? OK. You don't necessarily have
03:54 be OK with it, but you , test stuff probably won't come until
03:58 the exam, right? If you're about scores, if you're worried,
04:03 and talk to me, I my office hours are right after
04:05 I'm not going to yell at People who come to see me.
04:08 , you know, it's, it's to talk to a professor.
04:10 I'm a normal guy too. I up, I eat food.
04:14 I beat up Children. No, don't do that. No,
04:18 I'm easy. Just, just if nervous or concerned, come talk to
04:22 , I'll help you. I stayed school. I know how school
04:26 I, I liked it so I stayed right. So, don't
04:30 afraid to come and talk to I'll help you. I'll help you
04:31 with that. All right. but anyway, so are we,
04:35 we OK with what the strategy is now? Ok. All right.
04:39 this is just our starting point. is kind of view that big
04:43 The urinary system isn't just the It actually consists of the ureter,
04:47 consists of the bladder, what we the urinary bladder and it consists of
04:50 urethra. In the big picture, grand schema thing is the kidney is
04:55 for making urine. It's responsible for the blood and taking out materials that
05:00 body doesn't want or need. And it allows that stuff to be moved
05:06 the blood and then passed from the through a little tube to pass it
05:10 a storage space because you're always making and then that storage space holds it
05:15 there's enough fluid for you to go the bathroom. And so the ureters
05:19 the path between the kidney to the . The bladder is a holding
05:23 right? Because we're not all peeing now, but we're all making
05:27 All right. And then once I enough of it, it's like,
05:30 , I feel the need and off go and then the path, the
05:33 between the bladder and the bathroom is urethra and the urethra has dual function
05:40 males. It serves not only as path between uh for urine from
05:44 from the bladder to the bathroom, it also serves as the ejaculatory structure
05:49 which semen is passed during copulation. right, females, it's just urethra
05:55 just the pathway from the bladder to bathroom right now, in terms of
06:01 , what does the urinary system Right. It's actually pretty simple.
06:06 a general theme and you can see down there on the bottom. It's
06:09 for conditioning the blood. That's the picture. But if you kind of
06:13 down into it and ask these what, what is it exactly
06:18 Primarily it's responsible for filtering the blood removing the waste products in the
06:23 Now, when we talk about waste , we're really talking about nitrogenous
06:27 right? So when you break down acids, when you break down nucleic
06:34 , when you are exercising, you down muscle fibers and other things,
06:40 know, at these things produce nitrogenous , wastes nitrogenous waste. And so
06:48 stuff can be dangerous to the And so what we do is we
06:52 it off in the form of uric urea and um I'm blanking on the
06:58 one right now, but that's how get rid of that stuff. And
07:01 it's passed out of the body through urine. The other thing that we
07:05 is we're going to convert this this, these waste products that our
07:11 is doing and we're going to sort it and actually ask the question is
07:14 stuff we really want to get rid . It's like, like going through
07:17 junk drawer, right? You've put that you don't think you want into
07:21 junk drawer into a box and before throw it out, you kind of
07:23 through it and go do, I want to get rid of this
07:26 And then it's like, well, , oh, this is something I
07:29 to keep. And so we're going process that, that material, what
07:32 call the filtrate. And that's what results in creating the urine. And
07:37 , ultimately we eliminate. And so kind of what we're focusing on.
07:41 there's other things we're going to focus little later. When we talk about
07:44 uh endocrine system, we'll talk about formation of calcitriol. Calcitriol is the
07:51 word for saying vitamin D, We're going to see or we've already
07:55 about er, erythropoetin and how it's to make new red blood cells.
08:00 what the kidney is responsible for. then it regulates your ion water
08:04 So it's water salt balance, which blood pressure. It also plays a
08:08 in major, regulating your acid base in your blood. And, and
08:13 I found is that when I talk to try to throw those things
08:16 we end up with way too much . So we're not even gonna bother
08:19 it. All right. But just your kidney plays a role in making
08:23 you're at the proper P H and just gonna leave it at that.
08:28 right. And it also plays a or it could play a role in
08:31 is a process called gluconeogenesis. Gluconeogenesis saying I make new glucose. And
08:37 what we're doing is we're taking amino and we're converting them into ketone bodies
08:42 are then converted into glucose. And the kidney is capable of doing that
08:47 certain conditions. And so it ensures your body has the nutrients, it
08:51 to power the the things that, you do primarily what the brain
08:55 All right, but if you look all of these different things,
08:58 Ion base or ion, ion salts water balance and ion balance or acid
09:05 balance and, and moving waste and like that. Each of these things
09:10 looking at the blood and asking the , is it improper balance? And
09:13 conditioning the blood is how we think what the kidney is doing. It's
09:18 the blood work the way it's supposed work. In other words, make
09:23 it has the proper concentrations of So that's kind of the big
09:28 And what we wanna do is we to focus in today, like I
09:31 on the kidney and we'll talk about S and urethra and the bladder,
09:34 , um, we'll talk about, , I think it's on Thursday.
09:37 might be next on the Tuesday when get back. But this again,
09:42 aren't, aren't, aren't that big a thing to talk about. It's
09:45 all the action is taking place here the kidneys. And so what I
09:49 to first point out is where the are located and what they look
09:52 And you can see in the picture looks like a bean. I
09:54 we talk, we talk about kidney . They name the bean because they
09:57 like kidneys, right? But you see here the kidney is this bean
10:02 structure on top. It has a that looks like a dollop of whipped
10:06 . It's called the adrenal gland. deal with that. When we get
10:08 the endocrine system, it's not part the kid, it's separate from
10:12 but it's wrapped, it's found on posterior side of the abdomen. So
10:16 you were to dissect, you'd find way back here. It's partially protected
10:19 the ribs and it's wrapped in a bunch of unique layers. It's actually
10:25 we say is it's found behind the peritoneum. Now, the perineum,
10:30 we haven't talked about, we'll get when we talk about the digestive system
10:33 the, is the serious membranes that found inside the abdomen. And there
10:38 some structures that are found between the layers or protected by those layers.
10:44 then there are some that are found on, on the back side.
10:48 other words, both layers sit in of the organ and the kidney is
10:52 of those. And so what we that is a retro perineal structure.
10:58 found in the retroperitoneal space. So basically not covered completely by a serious
11:04 . It's only partially covered on the side. Now, in terms of
11:10 actual structure itself, we're going to on the baseline, we're not going
11:13 work our way in, we're going work our way out. So the
11:16 itself has its own capsule. So basically a tissue that has this layer
11:21 connective tissue that holds it and makes shape and basically separates that structure from
11:27 else. All right. So that's first layer. And this is the
11:30 capsule. And then outside the renal , you have a layer of fat
11:36 we call the perinephric fat. And our picture, we can see the
11:40 fat. So there's your capsule, can see how they've pulled it
11:43 So in there, that would be renal tissue. So the capsule sits
11:47 top of that and then here's the that sits wrapped around the kidney,
11:50 the perinephric fat and then surrounding that a layer of connective tissue, which
11:55 just referred to as the renal And that kind of holds everything in
11:59 position in place. So it doesn't around the body and then outside
12:03 which is not shown here is another of fat, which is the para
12:07 . So perry means next two para around, OK. And I know
12:11 distinction there is kind of subtle but means around the whole thing. And
12:17 that would be like the abdominal that's kind of like what that's
12:20 All right. So it's not shown the picture, but you can imagine
12:24 outside here around the FAA. All . So we go capsule fat,
12:32 layer connected tissue fascia and then more . And that's what covers and protects
12:38 kidney so far, so good, ? If you were to take a
12:46 through the kidney and part of your is to do that, you'll get
12:49 dissect the, you know, the dissection and kind of look at this
12:56 is you'll see that the kidney has different regions to it. We have
13:01 cortex and the medulla and this cortex medulla have different roles which will come
13:05 learn over the next couple of All right. But you can clearly
13:09 the delineation here. If you were take a slice, it, you're
13:12 see one area is a little bit , the other area is a little
13:14 darker. And so you can kind see cortex sits out here. Uh
13:18 mela sits internally all right now, switched things around on the slide.
13:24 I was introducing things, we talked columns first, I think on what
13:27 get. But I'm moving first to pyramids and I want to point out
13:30 pyramids first because they're really overt and these triangular shapes that make up
13:36 the structure and the primary portion of module. All right. Now,
13:41 you look at this, you can of see in the cartoon that there's
13:44 everywhere, there's even lines up here the cortex. But the, but
13:47 pyramids really, you can see these rather clearly when you do that
13:53 All right. And what they represent first, the base of the pyramid
14:00 the point between the cortex and the . So it's a cortical medullary
14:05 All right. And then the apex a point of conversion of all these
14:11 lines that you see. And the lines, the striations are the nephrons
14:16 early, the collecting tubes of the that we're going to talk about a
14:19 bit later. So these are microscopic that are so um um there's so
14:26 of them that they actually make their visible by the naked eye between the
14:35 are the columns. So this this structure so on and so
14:40 All right, those are the columns the columns are extensions of the cortex
14:45 kind of push in between the uh pyramids themselves and so it kind of
14:50 the pyramids overt easy to see. , there's a term that some anatomists
14:56 using, it's called the lobe and are no true lobes here. In
14:59 words, a lobe is usually a that's demarcated by some connective tissue.
15:04 that one part of the structure is from another part of the structure.
15:07 don't see that here. But what do is we can take an imaginary
15:10 right up the middle of one of columns and up in the middle of
15:13 other column and then right to the of the, to the end of
15:17 kidney. And so everything in there includes a pyramid, the two halves
15:21 those columns represents a lobe. And that would be what it was a
15:25 lobe. And so it's just kind a way to say here is a
15:29 that has functionality together. All And it's this is becomes more clear
15:35 you start looking at the, the vessels that are working into these structures
15:40 the blood vessels are basically surrounding each the pyramids. All right. So
15:46 have each of these little areas. have the pyramids, we have the
15:50 , we have a lobe which represents pyramid plus half of the column are
15:55 it if you go internal to the . So the central portion of the
16:04 here is referred to as the renal . And in the renal sinus.
16:09 have these larger structures that become very overt they're referred to as the
16:14 C. There's Minor Ks and Major of CS. So we have a
16:18 K C that's for each one of pyramids. And what they are really
16:23 microtubules or micro tubes that you can't with the naked eye. They come
16:29 and they form this larger basin like . So what they're doing is they're
16:35 fluid from these little tubules that are of the pyramids. And then the
16:41 K CS converge and they form the Kless C. And so you'll see
16:45 to 3 of these per pyramid. so where the demarcation is, is
16:49 always 100% clear, but you can , all right, there's a
16:52 there's a minor, there's a there's a minor. So this region
16:55 here where all they can converge those converge. That would be a
17:00 But where the dividing line begins between minor and the major is a little
17:04 less obvious. And then the major C. So if that's a major
17:10 C and that's a major K the region where those two things converge
17:14 referred to as the pelvis. So have a renal pelvis and so you
17:18 think about it like this, I little tiny tubes. I can't see
17:21 converge to form big kind of in or big tubes which then converge form
17:26 bigger tube which are really, really . So it doesn't look like a
17:29 which goes into a big giant That's the pelvis. And the pelvis
17:34 what is going to form the, it leaves the kidney, the region
17:43 the exits, where the vein um and where the artery enters as well
17:48 the limp vessels which aren't showing here referred to as the hill. And
17:52 think on your slide it says helium I'm an idiot and I type an
17:55 , every time I spell out. . All right. So Hiems,
18:01 gonna see any structure where you have vessels going in. We saw the
18:05 when we talked about the lungs, gonna see a hi, when we
18:08 about the liver, we're gonna see hi when we talk about the pancreas
18:13 are basically where things enter into All right. And so here the
18:17 is very, very obvious because your has that bean shape to it.
18:21 so everything is going in where the of the bean normally is located.
18:28 that's your macrostructure. Macrostructure is pretty . Do you think pretty straightforward?
18:33 you draw a kidney and label all parts? Yeah. Ok.
18:38 that's, that's it for the big . Everything now is microscopic,
18:43 And this is where all the action place is in the microscopic,
18:47 And so this is part of the why kidney gets a little bit difficult
18:50 we're looking at things that we can't except under the microscope and when you
18:54 your histology courses, when you go to nursing school and they make you
18:57 at all these slides and you're I don't know what the hell I'm
18:59 at. It's gonna be even harder you're looking at a bunch of
19:03 That's what, how, you you, where, you know,
19:05 looking at the kidney because everything is bunch of tubes jammed in there,
19:09 ? And the structure, we're looking the thing where all the action takes
19:13 . The interesting part about the kidney this thing right here is called the
19:17 , right? And there are hundreds thousands of nephrons, right? They
19:22 two major units. We have the puzzle. Core puzzle is simply this
19:28 structure right here. It's the point we have a blood vessels going in
19:32 coming back out again. And it's point where our tube begins. All
19:37 . And then the other part is renal tubule which you can see kind
19:40 goes around and around and around and and like that. And there you
19:43 , it's all just kind of mish together. In fact, some of
19:46 names suggest how strange and structured it and how windy it is. All
19:53 . So when we look at the , we need to remember there is
19:56 point of contact between the tube where filtrate is being made, where urine
20:01 going to be made from. And a point of contact with the blood
20:05 . And so there's going to be exchange point. And that's what the
20:08 puzzle plays. It plays a role terms of filtering the fluid from the
20:13 and exchanges it and puts it into f as a filter and allows it
20:18 go into the tube and then the of it is just the tube where
20:22 going to do further processing. both of these units are going to
20:27 exist within the cortex. All And where they exist in the cortex
20:32 going to be a big deal a bit later. All right. But
20:36 going to see most of the Nephron up here in the cortex, a
20:41 portion called the Nephron loop or the of Henley or loop of Henle.
20:46 honestly, I don't know how the pronounced his name. I've had professors
20:50 it one way, professors pronounce it way and no book will tell you
20:53 which way to pronounce it. All . So that's why I think they're
20:57 to get rid of all the, names. It's like the, the
21:00 stuff is like, oh no, don't, no one knows how to
21:02 it. But if you think of loop, when you think of the
21:05 loop, the Nephron loop, the of Henley loop of heel. This
21:08 a portion that's actually found in the , that's the pyramid portion. And
21:13 when we say we can see those , what we're looking at is we're
21:17 at this action down here. So cortex is everything else part of the
21:23 , the pyramid or the medulla are long elongated loops of Henley. There's
21:30 the collecting ducts which we'll get to a little bit later. So I
21:33 to focus in first on our little puzzle here. All right. So
21:40 we're gonna do is we're gonna first at the blood vessels and then we'll
21:43 at the tube itself. OK. I, I think it's easy to
21:47 it that way because you got to in terms of what is my
21:51 All right. So in terms of , the Glaus is a ball,
21:56 of capillaries. And this is a capillary. This is not a capillary
22:00 plays a role in uh blood exchange the exchange of nutrients between surrounding
22:06 In fact, the glomeruli is this structure that exists between two arterials and
22:13 doesn't sound right? Does it? supposed to have arterial then capillary?
22:17 then what veal, right? And , we don't have that. We
22:23 an arterial, then we have this and then we have another arterial.
22:28 so what this is, is really modification of an arterial so that the
22:33 can do what it does. And just this really, really strange capillary
22:38 that's kind of built into a ball structure that sits between these two arteries
22:43 it's stuck inside this capsule. All . But this is where the site
22:48 exchange is going to take place. is where the fluid from the blood
22:52 going to be moved into the Right. So that's the first
22:56 that's the glomeruli. So I have here, water plus other stuff are
23:01 to be filtered here inside that little vessel that's in there, that
23:06 Now, the blood going into the is going to be an arterial that's
23:10 the aerin arterial. All right. then the blood coming out on the
23:15 side is coming out via another arterial the EENT arterial. So A is
23:20 , E is second. All And again, it's probably afferent and
23:24 . But you know, if we that in Texas, it's just gonna
23:28 weird. So it's a and EENT helps us to, to distinguish between
23:32 two. So we go a arterial the glome list out via the E
23:37 . And you can see that in little pictures here, here's our a
23:41 the glome and out via the E . So that is the blood
23:47 the vascular side of the core pus structure that surrounds the glomeruli and under
23:56 or in which the ara comes in goes out is called the glomerular capsule
24:02 more familiarly called Bowman's capsule named after guy that identified it. All
24:07 And so Bowman's capsule is a bunch epithelial tissue that is like a blunt
24:13 tube that you've pushed this glomeruli And so you have epithelium that sits
24:20 up against the structures of the We're gonna deal with this picture a
24:25 bit more clearly, a little bit . All right. And so it
24:29 as the tubular side of the core . So if the glomeruli is the
24:35 side, Bowman's capsule is the tubular . And so the exchange is going
24:38 be from the blood on the inside the glomeruli through the walls of the
24:43 of the capillaries and then through the into this open space that is Bowman's
24:50 and then Bowman's capsule is then going kind of move on and form the
24:54 of those tubule uh moving on down that will get to. So you
24:58 think of the the core puzzle as halves vascular pole, tubular pole things
25:04 from the blood, moving to the . That's the easiest way to kind
25:09 think of these two structures. So far are you with me?
25:18 . Moving down through the tube, we're going on through the tube.
25:22 have this first region you can see winds all over the place like
25:26 all right. So this windy structure nearest the glomeruli and near as Bowman's
25:33 . So it's near as the core . So we say it is
25:37 that's where it's got its first half the name. And because it winds
25:40 over the place, it's convoluted. proximal convoluted tubule. All right.
25:48 then it gets even more complicated. you want to get down, there's
25:52 a proximal straight tubule, but we're going to deal with that. You
25:55 kind of see where it straightens out what it does is it then enters
25:59 the mela and dips down and then back out in this weird hairpin
26:05 All right, this hairpin loop is Nephron loop or loop of Hindley.
26:11 . Now, you can see the loop has this kind of structure.
26:13 starts off fat and ivory cartoon you at and they're trying to demonstrate there
26:18 something unique going on here. It really, really thin for a little
26:21 while. And so we have this that's thick, that becomes thin and
26:26 it hair turns or it turns and it becomes thick again. And so
26:30 refer to the side that's going down the proximal convoluted tubule is that's the
26:35 the descending limb, all right, then it turns on itself and then
26:40 goes back up, that's the ascending . And so you can see
26:43 they've also labeled it this side as , this side is thick and
26:47 those appearances there are, are for the, the thickness and the
26:51 are a result of unique changes that occurring inside the loop which we're not
26:56 get into right now. All we'll deal with that in a,
26:59 a, in a couple of All right. But the idea here
27:02 we have these structures that are unique they have different functionalities, right.
27:09 we descend and then we ace in back out again. So we're stuck
27:13 the mela for only a very short of time. And then when we
27:18 , we go out through another windy . So it's convoluted, but because
27:22 not near, it's far away, refer to as the distal convoluted tubule
27:26 sometimes you'll see it labeled just distal . Now, the distal convoluted tubule
27:35 going to join up with this larger called the collecting duct. And so
27:39 can see for every collecting duct that a series of nephrons associated with
27:45 So you can think of it like tree that has a whole bunch of
27:48 . So you might see anywhere between and 12 nephrons associated with the single
27:53 duck. And it's the collecting decks continue down through the medo and keep
27:57 striations and it's what are going to up and form those minor minor.
28:03 filtrate. So blood is coming through being filtered and turning into what is
28:09 a filtrate. The filtrate passes through the different regions, proximal convoluted
28:15 the loop of Henley back through the convoluted tubule and then down through the
28:20 duct and then that's where you're making from. It's through all those different
28:25 that you're making adjustments or modifications to filtrate. Now, this is a
28:32 picture, but this is what it like. More or less. It's
28:36 to look at a structure like this you can see it a little bit
28:39 . All right. So here you see the aar arterial. There's your
28:42 , there's your ear arterial. You see here's the proximal cotton valided tubule
28:47 out. There's the loop of Henley limb, aying limb. And then
28:51 the distal convoluted tubule and then down the collecting duct, you'll see that
28:56 of them mark this small region over and they call it the collecting
29:00 And so we'll just define that just , collecting tubules are simply the small
29:06 between the collecting dup and the distal tubule. Little tiny, tiny
29:12 Ok. So structures in terms of nomenclature so far, so good,
29:20 you draw it out, you Ok. Now, since we know
29:28 nephronic structure, we need to understand there are two different types of nephrons
29:34 based upon where you find the core of that Nephron. All right.
29:40 if the Nephron just exists pretty much in the upper regions to like the
29:44 regions of the cortex, we could to them as cortical nephrons. If
29:49 find the core puzzle near the mela low in the module, we call
29:54 a very low in the cortex, low in the module but low in
29:58 cortex. We refer to it as XTA medullary Nephron. All right.
30:04 means next to. So next to mela, right. So notice they're
30:08 named for where they're positioned right If that was all there was to
30:13 , they probably wouldn't have to name , but they actually have some very
30:18 uh structure associated with them. And is what this picture is trying to
30:23 to you. All right. So notice in this, we have two
30:27 nephrons. We have one up right? This is the cortical one
30:32 you can see it does all its thing. There's a proximal convoluted
30:35 there's the loop of HILA comes down goes back up and there's your distal
30:40 tubule and it joins up with the duct, right? Not too
30:44 But here when we have our juxtamedullary , look at associated with that loop
30:51 Handley. We have this unique structure associated with it. These blood vessels
30:55 you don't see over here associated with Cortical Nephron. So there's two features
31:04 you should be, be observing The first one is the depth to
31:08 the loop of Henley goes, cortical , loop of Henley just kind of
31:12 its toes into the mela. It's kind of like I go
31:16 oh, I don't want to go out again. All right, just
31:19 me, they travel deep, deep and then they come back out
31:24 . And then with the cortical it lacks this blood vessel where here
31:30 can see the blood vessels travel alongside nephronic loop or the loop of henley
31:36 move back out again. This is type of blood vessels are referred to
31:40 the vasa recta. All right, majority of your nephrons are these cortical
31:48 . All right. They're just doing job filtering them the the blood making
31:54 and changing the filtrate and making All right. So when we think
31:59 what the kidney is doing, this kind of the big picture stuff.
32:02 is what most of your nephrons are . All right, the ju IED
32:09 . On the other hand, while doing the same things that the cortical
32:12 are doing. These long loops of are responsible for changing the nature of
32:19 interstitial fluid of the mela. I'm gonna kind of jump out here
32:25 a second to kind of explain this your body. You have water plus
32:31 , right? And if we counted all the little things that are sitting
32:33 all that water, what we would is we would find that you have
32:37 osmotic value of your body you have osmolarity and that osmolarity throughout your entire
32:45 is around 300 milli osmoles, which English means you have about 300 particles
32:52 substance per liter. It's actually, , it's, it's milly osmos,
32:56 osmo 300 mil osmos. So you , you have particles per unit volume
33:01 fluid and it doesn't matter where you it. And we notice we don't
33:06 what the the material is, it be ions, it can be
33:09 it can be just stuff. All . So no matter where you
33:12 you take a little sample of the from your brain, a little bit
33:14 sample fluid from um uh your a little sample from your big
33:20 Look at the fluid, it's gonna measuring up to 300 mil osm.
33:25 . The mela is different the the kidney has a gradient to
33:31 It starts off like the the cortex 300 mil osmoles. But as you
33:36 down through the mela towards the um uh towards the pelvis, the the
33:46 of solute gets greater and greater and and greater and it gets as,
33:52 high as 1200 milli osmoles. So times greater. And it's this osmotic
34:00 of, of solute that your kidney to help you make urine of varying
34:08 of fluid. All right now, to paint the picture and we'll explain
34:14 all a little bit later. But just want to paint it. Have
34:17 noticed when you drink a lot of ? Your peas looks like water,
34:21 ? Have you noticed that when you dehydrated, your pee looks a little
34:24 darker, right? More golden. in fact, if you get it
34:29 like that Aggie maroon color, that's dangerous color and it can get that
34:33 . Don't get there. All That, that's bad. That's
34:36 Go to go to the hospital All right, you notice that.
34:40 other words, when your body is , your body wants to keep water
34:45 it and when you have too much , your body is trying to get
34:48 water. All right, the reason able to do that is because of
34:53 osmotic gradient created here by those Juul . So all that module is modified
35:04 of the presence of that loop of going down deep and the vas erecta
35:10 associated with it. And we're not talk about how that's gonna be
35:16 OK. But I want to put up here at the front end so
35:20 you know what's coming. OK. . All right. I mentioned there's
35:28 other structures, the collecting tubules, I mentioned, it's, here's the
35:33 convoluted tubule. The collecting tubule is the short in between the collecting dep
35:37 the distal convoluted tubule. Um It's particularly important for us. So you'll
35:42 not even see it ever again. collecting duct is the large structure.
35:48 that tree on which all the nephrons hanging via their distal convoluted tubules.
35:52 . This passes through that osmotic gradient the module. And it's what allows
35:59 to start modifying the last little bit the, of the filtrate that we've
36:04 to pull water in or to allow to leave. So it plays an
36:08 role in in um uh changing the concentration in our filtrate. There's two
36:16 types of cells in here that are in the collecting duct. It's the
36:21 cell. Why do you think they're principal cells? They're the main
36:27 That's exactly right. See, they are primarily until you get into
36:31 of these tissues. And you're really they have the like the tissue
36:34 worked on was the epi which were most common type of cell were called
36:38 cells. And then there's another type cell, really important cell called the
36:41 cell. Why is it called the cell? Because it was clear,
36:46 ? I mean, this is how , I guess we are. The
36:52 type are inter collated cells right These are the ones that play an
36:56 role in monitoring ph in the body in the urine for that matter.
37:02 is the one place in this entire universe where you're gonna have the easiest
37:07 to memorize. All right. So just memorize it, you have the
37:11 a cell and you have the type , intercooled cells type A cells are
37:16 , are responsible for eliminating acids. A for acids, type B cells
37:23 base B for base, first time the entire universe that someone names something
37:29 . All right. So there you , we're not going to talk about
37:32 whole processes, but you should know intercooled cells type A type B.
37:36 helps me eliminate acids when my P too low. Type B, when
37:39 P gets too high, I'm I'm base. All right, if you
37:50 at the picture up there in the left, right up here, this
37:54 trying to show you um the structure the left front again. So you
38:00 see there's your glome. So here's hand, it's a glome,
38:03 You got the proximal convoluted tubule, goes loop of henley and goes on
38:07 it forms that distal convoluted tubule. if you look, where does that
38:10 convoluted tubule end up. If this the glomeruli, it goes right by
38:15 glomeruli like so OK. Right. by Bowman's capsule or the core
38:22 All right. Now, remember the puzzle exists a vasculature. So you
38:27 the glome and then you have the and the E fence arterial. So
38:31 distal convoluted tubule literally passes between the and the E ference arterial.
38:37 Big deal, Doctor Wayne. So ? Well, this is actually a
38:43 associated the XTA glomerular apparatus So look at the name XTA means next
38:50 the glomus, right. So next the glomeruli apparatus and what it
38:57 the glam apparatus is responsible for regulating flow of blood into and out of
39:04 glori dependent upon how fast the filtrate moving through. So you can see
39:40 my distal convoluted tubule, there's my arterial, there's my EENT arterial,
39:44 glome will be sitting over there So we have granular cells and you're
39:49 the granular cells marked off here in little picture as a little bit darker
39:55 for the Book Man Purple. And the granular cells are, these are
40:01 muscle cells, but they have special in them. All right. And
40:06 they're doing is they're looking at the of stretch that's going on and they
40:12 have um receptors to respond to signals the distal convoluted tubule. And so
40:18 they're stretched, what they'll do is will contract to limit the flow
40:24 In other words, they play a in auto regulating and managing the amount
40:28 blood flowing into the a arterial. second thing that they do in response
40:36 what the macula dens cells you tell . And then we'll get to that
40:39 a second is they produce an enzyme released into the blood. This is
40:46 rein and renin plays a role in long term blood pressure. We already
40:51 about that. Remember that the renin aldosterone system. So, when your
40:57 pressure rises, right? Or, excuse me, when it falls,
41:03 when it's like, oh, we to release seren so that we can
41:07 our blood pressure. All right. it's going to be through that longer
41:12 . But how do I know when blood pressure gets high or low?
41:16 , this is where the other group cells and these are the macula denso
41:19 and they're part of the distal convoluted here, you can see them.
41:23 don't even know what color that All right. It looks like a
41:27 of brown and blue. It's a color. All right. So these
41:33 cells and what their job is is have receptor on their surface that are
41:39 sodium chloride, both sodium and chloride by them. And so literally what
41:44 do is they just sit there and , they read the filtrate. So
41:48 filtrate is going by them, going them. And as you come into
41:52 with salt, basically it's going This is the rate at which I'm
41:56 salt. And if that rate right. In other words, if
42:02 rate drops, that's an indication that blood pressure has dropped because the primary
42:07 force of that making of the filtrate going to be blood pressure, which
42:11 learn about here at the very end the class. So salt levels
42:16 That's an indication that the blood pressures . So I need to tell the
42:21 to raise the blood pressure. So going to tell the granular cells,
42:25 , release the rein, it releases . Then rin goes and does its
42:29 to cause the conversion of angiotensinogen into . One which gets changed into angiotensin
42:35 yada yada yada yada. OK. that's part of the distal convoluted
42:42 And because your body is not just bunch of empty spaces, there's also
42:45 that are located in and around. are called the extra glomerular mazal
42:52 So there's, there's some that are within and some that are found within
42:56 glomeruli. The extra glomery means are and we don't really know what they
43:00 , but they fill up the space they probably have an important role.
43:04 just don't know half the stuff we we do. So um there's that
43:10 this structure make sense to you kind sort of process? Maybe not so
43:16 . But structures. Granular cells regulate pressure release rein macula cells measure salt
43:24 the filtrate to tell the granu cells to do. OK. Other cells
43:30 clue. But they're there pausing for moment. Let your brain soak that
43:38 for a second. Now, all blood in your body passes the entire
43:50 of your body. Um roughly every or so, I cannot remember the
43:54 amount. It's very fast. And your kidney is constantly in the process
43:58 filtering uh the blood. All And so blood moving into the kidney
44:03 via the renal artery, it goes the different segments via the segmental
44:08 So you can see two segmental arteries then the first artery that you're going
44:13 see is going to pass through, through the columns into the lobes.
44:19 these are called the inter lobal, , inter lobal arteries. And then
44:24 can see they're going to get smarter smaller and smaller. And so what
44:28 going to do is they're going to up and around, they form an
44:33 , hence the name arcuate arteries. then what they do is they then
44:37 out through the cortex. You can the radiations. Those are the cortical
44:45 arteries. Ok. Well, it's the cortical radiate arteries that we're gonna
44:50 our a a arterials, our aph then form which structure starts with a
45:01 , the glomeruli and from the glomeruli get which artery EENT arterial?
45:07 All right. So do you see have a pathway here? All
45:10 Now, notice these are arteries and going to eventually have to form a
45:15 system because you have a whole bunch blood or a whole bunch of cells
45:18 need their nutrients. And so blood is blood even though we're filtering it
45:24 we still need to do gas exchange nutrient exchange to all those cells.
45:28 so those arteries, those little tiny EENT arterials form the actual capillary system
45:35 is responsible for providing the nutrients for kidney. These are called the para
45:40 capillaries. All right. And the cartoon you can see the peritubular capillaries
45:46 all wrapped around, all wrapped around here, so on and so
45:49 All right. And again in the , no cell is more than a
45:54 of microns away from a blood All right. And that's what the
45:59 capillary's job is supply the kidney with blood. But we already mentioned,
46:05 have these weird blood vessels moving down these are part of the juxtamedullary
46:11 And these are para tubular capillaries that been modified to follow along the length
46:18 the loop of Henle. And these the vas erecta. So they are
46:21 a capillary system. And what they is they run in the opposite direction
46:28 the loop of Henley. So when loop of Henley descends and then
46:33 the, the vas erecta is descending the or where the ascending limb is
46:38 up. So they're moving in opposite , kind of like traffic on a
46:43 . Can you, can you envision on a highway, right? You
46:47 northbound and southbound lanes. So where ascending limb of the Lipo Henley
46:52 you have the descending arms or the vessels of the vasa. And whenever
46:59 have two things running alongside each other opposite directions, you have a countercurrent
47:05 counter is opposite current flow. So things that are flowing in opposite
47:10 So you have flow going in opposite this way and you have flow going
47:15 opposite directions this way. And what capillaries do is they allow for the
47:23 of water and other substances in the . And if the loop of Henley
47:32 responsible for establishing the uh um the gradient that I described in the
47:43 the vas erecta ensures that, that gradient exists because we're gonna see materials
47:52 back and forth. And because these are moving in opposite directions, if
47:56 is picked up, it can be back to where it needed to
48:01 And so it, it helps to the osmotic gradient that we established through
48:06 loop of handling. All right, it is similar to the peritubular
48:13 Now, the way you can think this in terms of what it looks
48:15 , does it look like? And , I don't know what types of
48:18 these are but those long dr draping , you know what I'm talking
48:24 You have multiple, yeah, that's they kind of look like. And
48:27 just run alongside those loops of Henley of the ju imaginary nephrons, you
48:33 not see them associated with the cortical , then moving back out, you
48:40 cortical radiate veins. If I go , you can see where they join
48:44 again, they come right back up then they join up with the cortical
48:47 veins. There's the cortical radiate veins there. Then you have the arcuate
48:52 which then goes to the inter lobal . So in terms of nomenclature,
48:56 move in and you move out basically same way, uh the names are
49:00 , very similar, the vascular seem back there. I can see you
49:07 falling asleep and reading your phones. , I know. Does that make
49:14 ? Yeah. No. Yeah. , six people in the front say
49:18 , four people in the back. . No, you can look
49:25 I still, I still see your . Yes, I got one thumb
49:29 from the back. All right. . Question. You speak up a
49:38 bit. Yeah, they're just part the smooth muscle that makes up the
49:44 wall that surrounds the aer arterial. and remember an arterial, I'm just
49:52 up an arterial is epithelium, And then uh basically smooth muscle and
49:59 connective tissue that surrounds it and holds together. So the graner cells are
50:02 to the smooth muscle in that particular that allows them to uh produce that
50:08 All right. So there's, there's smooth muscle cell in that location,
50:13 just say smooth muscle cell. That's . Any other questions? So you
50:24 if I asked you tell me the of blood through the kidney, starting
50:28 the renal artery? Yeah. Renal inter glob, arcuate cortical,
50:38 a glaus EENT peritubular or vaz erecta then just the opposite again. All
50:49 . Now, I can do that I've done it for 15, some
50:52 years. But all you gotta do just draw it out, you draw
50:56 out and you'll see the flow, ? Drawing is your friend that is
51:05 anatomy that you need to know. . Everything we've described at the point
51:11 all anatomy, right? What we're do is we're now going to move
51:18 a function, right? It's the because ultimately, what we're trying to
51:24 with the kidney is to do. , what is the kidney's job?
51:28 urine, right? You get to home tonight and you say mom,
51:33 what I learned today, I learned to make urine and she's gonna be
51:37 proud of you. It's like yay wait till we get to digest.
51:43 can say I made poopy. we won't say it that way.
51:47 . All right. So there's some that we need to understand. So
51:53 , this is a system that is for filtering blood and turning into
51:59 but it's not an immediate thing. blood does not immediately turn into
52:05 right? The first thing when blood passed through the Gloria that fluid that
52:11 through is referred to as the That is the term we use.
52:15 just the stuff that's in the No modification has taken place, it's
52:19 material that we've taken from the And then as it begins passing through
52:24 tube, that filtrate becomes modified. we have a different term we
52:28 we call it tubular fluid. I'll probably stick with the term filtrate because
52:32 shorter, right? But tubular fluid not filtrate. There has modification has
52:38 taking place. There are three processes going to learn about that help in
52:42 of changing that filtrate towards urine. this tubular fluid is a result of
52:49 processes that are going on. And ultimately, after that fluid passes through
52:55 distal convoluted tubule begins going down that duct. The last stages of modification
53:01 taking place and when that fluid enters the minor calas or the minor Cali
53:08 , you no longer can make modification it. You have formed urine.
53:14 urine is formed and then once you it, it can't be modified any
53:19 . So once it's made, it what it is, all right.
53:25 so that urine then passes from the Cali to the major Cali into the
53:29 pelvis out through the and on to bladder and you can't modify it uh
53:36 . So the filtration membrane, the step means what do we do?
53:39 do we do this filtration? the glome and this is where I
53:44 trying to get to is here. are in the Glaus. You can
53:46 our aar arterial the EENT arterial. right. And so we're going to
53:51 with endothelium, that's going to be first layer, the blood has to
53:54 through. So we have uh uh endothelium of the cells basically uh
54:00 with gaps and stuff that allow material pass through. And then between that
54:06 and the cells that make up the of the Gloria, what we have
54:10 we have connective tissue that's kind of a screen to make sure that only
54:14 that are small enough can actually pass it. So that's the basement
54:19 All right. So we're limiting this large substances like blood vests or blood
54:26 and big proteins. But then as move downward, you're getting rid of
54:30 the larger proteins that could have escaped . And then finally, what you
54:34 is you have this visceral layer of that are part of the glomeruli itself
54:39 remember it was a blunt tinted, tinted structure that got pushed inward.
54:44 so the cells of the glomeruli are up against the walls of the endit
54:50 . Now, these cells, they a special name. If you look
54:53 them, they have this kind of feature to them. They kind of
54:56 digitate. All right, like, right, so you have one cell
55:01 it has these little tiny feet is they refer to them as and so
55:05 feet are locked together. And so materials that can pass between the feet
55:12 small and tiny. Those cells are to as proto sites, foot
55:18 that's where they come from. All . And so only the smallest things
55:24 pass through there. All right. then also in, in these locations
55:31 , in these areas, these are I told you there's these mesal
55:34 these are the intra glama cells. again, they play a role in
55:40 how close the foot processes are because can modify themselves, they can get
55:47 close or they can expand outward. so you're doing micro regulation and that's
55:54 those mazal cells do. All But we're not going to concern ourselves
55:58 much with that regulation. So we three layers in athe connective tissue between
56:05 or, or not connection basement And then we have our proto sites
56:09 it's those three layers. If you're from the blood into the filtrates,
56:13 have to be able to be small to pass through those things. So
56:18 is kind of what it looks like can imagine up here. This is
56:20 blood. So you're moving through from Aron arteria, you're going to the
56:24 and those little tiny holes represent those layers together. All right. So
56:29 big things, they just keep they're retained in the blood that remain
56:35 of the plasma. But things that small enough water, plus these small
56:40 can pass through the filter and that's going on. I'm passing through that
56:45 into that space. And so what those things? Well, these are
56:50 , very small substances, freely freely filtered substances. Are those things
56:55 water and glucose, small peptides, , small vitamins, really, really
57:02 molecules that can pass through things that limited, include those things of intermediate
57:10 . Anything that's charged Are basically And the reason being is because those
57:16 have charges on their surface that repel larger charge substances and anything that's too
57:22 just isn't going to be filtered and to put this into context, about
57:26 of your plasma is filtered by the as it passes through. So if
57:30 think of a volume being 100%, it passes through, that comes out
57:35 about 125 mils per minute or 180 per day. How much blood do
57:40 have in your body? Five So let's just do the math real
57:47 . 100 and 25 times four Would 500 mills, right? So in
57:54 minutes, your your kidneys are filtering mills who has a water bottle,
58:02 lift it up, lifted high. 500 mils. That's how much is
58:07 filtered in four minutes, right? that by 10, right? In
58:15 minutes, your entire blood has been , right? That's incredible. That's
58:22 hardworking your kidney is impressive. All . Now, If that were true
58:31 , I'll answer your question a If that were true also, that
58:34 mean, um, in about 040 you would have no more blood
58:39 So, what that also means is a process that returns a lot of
58:43 filtrate back to the body. All . And so that's one of the
58:49 . So the first process, the step is filtration and then what we're
58:54 do is the second to two other . One of them is to reabsorb
58:59 materials. OK. And that's what talk about when we start on
59:04 Yeah, I was called to, . So the question is really
59:16 what does filtering mean? Right. the short answer. The short
59:20 right? And what filtering means is it's a nonspecific mechanism of moving materials
59:27 the liquid portion of the blood, the plasma and moving it into and
59:31 that filtrate that, that fluid. it's water plus stuff. But because
59:36 talking about things that are moving under nonregulated manner, that means we can't
59:41 what's being picked up. So notice of those things in that list is
59:46 , is glucose, something your body or wants to get rid of it
59:50 it. I mean, you worked for that glucose, right? I
59:53 , you stood in the line at Bell and so you, you work
59:58 that glucose and your body doesn't want give that up because that's energy that
60:02 needs. And so what we wanna is we don't want the things that
60:05 body needs to just be peed We only want to get rid of
60:10 things that our body doesn't need or to get rid of it. So
60:15 first step is just simply moving things that are small enough that we're trying
60:20 get rid of. The second step gonna be let's pull the things back
60:25 that our body still needs. Because of the things besides glucose is
60:30 your body doesn't want to just get of rid of water. Your body
60:35 to hold on to water that it necessary to maintain the chemical reactions that
60:41 doing. But if you have too water, you want to get rid
60:44 it. Yeah. So there's a here. It like let's just get
60:49 of the water and we'll figure out we need to hold back. All
60:52 . So that's kind of this, , this idea. So anything that
60:56 too big that gets trapped in our that's gonna be or eaten or destroyed
61:01 those intra or mesal cells and anything is small enough to pass through will
61:08 so. And the driving force of of this process is pressure. It's
61:14 blood pressure. All right. And what we're gonna look at is how
61:18 we drive this blood how do what is the pressures that are involved
61:21 ? And they're no different than the . We've already learned. We're just
61:25 one of them and we're gonna give special names, but they're no
61:29 I mean, we're looking at the pressure inside the blood hydrostatic pressure inside
61:34 tube. And then we're looking at colloid pressure inside the plasma. So
61:40 hydrostatic pressure is a pushing pressure. pressure is a pulling pressure,
61:47 Do you remember those? So inside glomeruli, we have blood pressure.
61:53 that's the glomerular blood hydrostatic pressure. a pushing pressure. It's driving fluid
61:59 the blood into Bowman's capsule. when you were a kid, did
62:03 ever play with a hose? Like in the yard spray? People run
62:09 . Were you ever stupid enough to a hose and stick it in your
62:12 ? Drink water? I mean, probably drink water this way but
62:14 you ever put it this way, to drink water fast. If you
62:17 to do that, what would Could you swallow fast enough?
62:22 Right. Because there's only a finite inside your mouth. And so if
62:28 put a hose in the flow would up that space really, really
62:33 And now the water would basically squirt the sides. But let's pretend for
62:37 moment that it can't squirt out the and you stick that hose in your
62:41 . So it's going to create a pressure, isn't it? Inside your
62:45 ? That's gonna fight against the water to come in. All right.
62:49 , so inside Bowman's capsule, we hydrostatic pressure that opposes the movement of
62:56 from the Gloria into Bowman's capsule. right. So that would be the
63:03 hydrostatic pressure. So in here, , hydrostatic pressure out here we have
63:08 blood hydrostatic pressure and then inside the , we have plasma proteins, plasma
63:14 say, hey, um I'm over water. You come join me.
63:17 remember it's a pulling pressure and so pulling water back. It's a it's
63:22 back pressure as well. So these pressure are what we use to
63:27 What is the net filtration pressure. right. Now, where's the colloid
63:32 pressure for Bowman's capsule? Well, doesn't exist because there are no plasma
63:37 . All right, it's, it's zero. So we're just gonna flat
63:39 , ignore it. So the net pressure, this is the differences between
63:45 . We have a pressure that's pushing the, into Bowman's capsule. We
63:50 a pressure that's pushing out of Bowman's . And then we have a pressure
63:54 into and away from uh well into blood, away from Bowman's capsule.
64:00 so you could just separate them Net filtration pressure is just pressure in
64:04 pressure out. So the pressure in the blood hydrostatic pressure. We can
64:09 it. It comes out to about millimeters of mercury. The out pressures
64:13 the Bowman's capsule, uh uh hydrostatic And the um, the colloid osmotic
64:21 that's pulling. And so you can those up. They have values 30
64:24 15, sum those together that's So 55 -45 is 10 of
64:31 So we have this positive pressure that's pushing blood from the glomeruli into Bowman's
64:41 . Now, can I modify What do you think? Sure.
64:46 one of the things we need to is we need to consider modifications.
64:49 so the net filtration pressure plays a in the rate at which we filter
64:57 . The greater the pressure, the we're going to filter the lower the
65:01 , the lower the rate at which going to to filter. Does that
65:04 of make sense? Again, if turn a hose full blast, I'm
65:09 water out faster, right? If turn the hose down, water pushes
65:14 less, still moving in the same , it's just not as powerful.
65:18 that's the same thing with net filtration is I'm just modifying those pressures.
65:26 , the back pressure from the glome stays more, more or less the
65:29 or Bowman's capsule stays more or less same, the colloid pressure stays more
65:33 less the same because I don't change number of plasm proteins in my
65:36 So really there's only one pressure that can modify, which is my blood
65:42 , right? And so I have afar arterial and I have an earn
65:46 . If I open up my aph , that means more blood flows into
65:50 glomeruli, which means I've increased blood inside the glomery list. If I
65:55 or constrict my afar arterial, I'm lowering the blood pressure, the amount
66:00 flow going into the glomeruli. So what I'm doing is I'm modifying at
66:05 aph arterial that flow. So, blood pressure at the aar arterial is
66:13 of the primary ways in which I the net filtration pressure, which modifies
66:19 glori filtration rates. That kind of sense. They over there are nodding
66:26 here if that makes sense. In words, if I want to filter
66:34 , how do I filter faster? up my blood vessel if I want
66:40 filter slower? What do I Close my blood vessel? And the
66:44 that I'm probably gonna be working with my a arterial. All right.
66:51 those are the primary ways we do . But what we do is we
66:54 that there are multiple ways that this happen, multiple ways in which I'm
66:58 regulate. I can do it. . Intrinsic means things that are part
67:02 the kidney itself, right? Or can do it extrinsically. All
67:08 Now, this should be intuitive at point for you. So if for
67:14 , um I increase my sympathetic what happens to my blood pressure,
67:19 goes up. So if my blood goes up from sympathetic activity, what's
67:23 to happen to my filtration rate, should go up, right? You
67:27 , so there's an extrinsic way that happens or what I can do is
67:31 my blood pressure is really, really , but I don't want it to
67:34 this high because this is dangerous. start blowing out blood vessels. So
67:38 can regulate inside the kidney itself by . That would be an example of
67:44 . So we have terminology for we call this auto regulation. So
67:49 regulation would be what's happening inside the extrinsically, we can regulate via the
67:55 pathways or what we can do is can do it through hormonal pathways because
68:02 just coming from different structures, that of makes sense. So let's just
68:08 a look at that really, really . You've already kind of understand these
68:12 , right? So renal auto regulation says, look over the course of
68:15 day, I'm not just a static , it feels like it because I'm
68:20 in class all day long. But truth is is you move around a
68:23 . And so when you move around lot, your blood pressure goes up
68:26 down a lot, right? And body is constantly modifying those changes.
68:31 we don't want to do that to kidneys. We don't want the blood
68:34 go up and down, up and because then the kidney can't function the
68:36 that it does. And so what kidney is trying to do is trying
68:39 maintain a constant pressure despite natural changes are occurring just in your daily
68:45 Right? So what you're doing here you're saying, look, I'm trying
68:48 maintain a normal static pressure inside my kidney. And if I do
68:54 then my kidney is gonna function more less the same no matter if it's
68:58 80 or if it's around 100 and . But if I get outside those
69:01 , then my kidney starts messing up doesn't start work, it doesn't work
69:04 same way. So as long as can keep it within this range,
69:07 in good shape. And so it's to use two different mechanisms to allow
69:11 kind of this activity. What is myogenic? And then the other one
69:14 tubular glomerular feedback before you even switch slide, myogenic. What does it
69:20 when you see my, what do think of muscles? So my muscles
69:25 play a role? All right. , it's not gonna be any
69:29 It's gonna be smooth muscles. All . The other one, tubule,
69:34 feedback tu below tubes, glomeruli, , right? So something between the
69:42 and the glomeruli are talking to each . Now, what structure did we
69:48 about? Where tubes and the glomeruli close to each other? The started
69:56 the J the XTA glomerular apparatus. , those are the two things that
70:02 gonna be playing a role here. , myogenic very, very basic,
70:09 gonna constrict constrict or we're gonna relax aar arterial. That's all we're doing
70:14 saying I want to maintain a constant pressure inside the glomeruli. So if
70:19 blood pressure rises in my body, the glomerular blood pressure would rise.
70:23 I don't want that to happen. what am I gonna do to counter
70:28 ? What, what would I do my blood pressure rises in my
70:31 How do I counter blood pressure rising my glomeruli? I constrict. So
70:37 gonna constrict my aar arterial. but my blood pressure has now dropped
70:41 my body because I've been sitting in lecture for an hour and 20 minutes
70:45 my brain is turning the pudding and slowly falling asleep. My blood pressure
70:49 dropping. How do I increase my pressure inside my glomeruli? I dilate
70:55 aar arterial. So that is the that we're doing here. That is
71:00 regulation. It's measuring the amount of inside the aar arterial and it's modifying
71:06 itself to match the needs of the . Now, you can do the
71:11 thing in EENT arterial. It's just the best way to do it.
71:14 can even see here. For if my G F R is,
71:19 getting too high, what do I ? Oh, well, why don't
71:24 just release the valve on the back . So more blood can leave.
71:28 that's not the more common way. common way is dealing with the amount
71:31 blood that's being delivered. Right. can, that's an easier thing to
71:36 on the front end than on the end. So that's why we focus
71:39 that with two marlar feedback. What doing is we're looking at the product
71:49 the filtration. All right. So we're going to learn a little bit
71:53 is that we're going to look at amount of sodium that's being filtered is
71:56 or less constant and the amount of of sodium back and forth into from
72:01 tubule to the body is going to more or less constant. So by
72:04 time you get to the distal convoluted , you know how much sodium should
72:09 there. And that's what those Maladenis are doing is they're measuring the sodium
72:15 the sodium coming by is lower than , that's an indication that the flow
72:20 the tubule is too slow. All . In other words, the fluid
72:27 moving fast enough if the fluid isn't fast enough, that's because the filtration
72:32 has dropped and the filtration rate we is dependent upon the pressure inside the
72:38 . So that's when I'm going to to the a arterial, right?
72:43 I'm going to tell those granular by the way, you need to
72:47 . And if you dilate. That I'm going to increase the flow of
72:51 into the glomeruli, which means the rate will go up, which means
72:55 sodium will go by. So here looking at the product of the
73:02 I'm not just looking at the pressure the arterial. The converse is true
73:07 well. If there's too much that means my filtration rate is too
73:12 , which means my blood pressure is high coming into the Glome Glaus.
73:16 that means I've got to constrict the arterial. All right. So
73:21 my communication here is I'm monitoring how filtering. I'm not just looking at
73:27 flow of blood into the glome. regulating the flow of blood in the
73:30 , but I'm doing it through this long pathway and it's really not long
73:37 they're right next to each other, it's the end of the whole
73:42 So it's the monitoring of the sodium that helps to modify through this
73:49 the flow of blood into the glome the aar arterial. So far,
73:55 kind of makes sense. All Last little bit has to do with
74:01 control. This extrinsic. So we've mentioned sympathetic, if I have increase
74:06 sympathetic activity, what I'm gonna do I'm causing vasoconstriction, right.
74:13 vasoconstriction will result in in a a in G F R. So what
74:20 doing is you're basically preventing that increased because remember the blood flow through the
74:26 is a lot faster. But what doing is we're saying here at the
74:30 we want to protect and so we're to constrict. So it's going to
74:34 the amount of flow into these right. So the other thing that
74:42 does, it decreases the surface So you get less flow into the
74:48 into the filtrate. But you also going to stimulate the production of
74:53 etcetera, etcetera. So it's going result in a, in a reversal
75:01 the process that is resulting in the pressure. The last little bit here
75:06 with A N P attic peptide. we said reduces or is a hormone
75:13 results in the lowering of blood And so here what's going to happen
75:19 when the A P goes to the , what it's going to do is
75:21 going to cause the aph arterial to . So, what we're doing here
75:25 as blood pressure is going down, opening up the kidney to allow for
75:31 flow of blood to go through so we can remove material from the
75:36 And that's allowing the blood pressure to down right through the filtration process.
75:41 right. So your glomery filtration rate up and your blood volume goes down
75:46 , is the the outcome here. right. In our last minute
75:54 let me just summarize really quickly. did some anatomy. I think the
75:58 is pretty straightforward. But we're taking first leap into understanding this process,
76:03 first step of the kidney, in of conditioning the blood is taking the
76:08 from the blood water. And plus the stuff that's small enough to go
76:12 and get its way into the That's the first step that's filtration.
76:18 we see how we can regulate that well. When we come back on
76:21 , we're going to deal with the of reabsorption and a tertiary process called
76:27 that's going to help modify that fluid urine. Ok.
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