Renal | Glomerular Filtration
Summary
TLDRDans cette vidéo, on aborde en détail le processus de filtration glomérulaire, pièce essentielle du fonctionnement rénal. Le corpuscule rénal est introduit comme une structure constituée du glomérule et de la capsule de Bowman. Le glomérule, un ensemble de capillaires fenestrés, filtre le sang en permettant le passage de petites molécules, d'eau, et d'électrolytes, tandis que les éléments formés comme les cellules sanguines sont retenus. La membrane basale glomérulaire et les podocytes (cellules avec des pieds) forment une barrière à trois niveaux qui empêche le passage de grandes molécules chargées négativement comme les protéines plasmatiques, grâce à des pores spécifiques et des charges électriques. Les pressions hydrostatiques et osmotiques à l'intérieur du glomérule régulent le taux de filtration glomérulaire (GFR), qui est normalement d'environ 125 ml/min. Différents facteurs, y compris la pression sanguine et les propriétés des membranes de filtration, influencent le taux de filtration glomérulaire.
Takeaways
- 🧬 La filtration glomérulaire est un processus crucial dans la fonction rénale.
- 🏗️ Le corpuscule rénal comprend le glomérule et la capsule de Bowman.
- 🩸 Les capillaires du glomérule sont fenestrés, filtrant le sang efficacement.
- 🔬 La membrane basale glomérulaire empêche les protéines chargées négativement de passer.
- 🐾 Les podocytes contribuent en formant des fentes de filtration.
- 📊 Le taux de filtration glomérulaire normal est de 125 ml/min.
- ⬆️ Une pression artérielle élevée peut augmenter le taux de filtration.
- ⚖️ Les pressions glomérulaires régulent la filtration.
- 🔄 La filtration glomérulaire est influencée par des facteurs pathologiques.
- 🩺 Une bonne compréhension de ce processus est essentielle pour diagnostiquer des maladies rénales.
Timeline
- 00:00:00 - 00:05:00
Dans cette vidéo, nous abordons la filtration glomérulaire, en commençant par la structure du corpuscule rénal, qui comprend le glomérule et la capsule de Bowman. Le glomérule est fait de capillaires fenêtrés, laissant passer certains éléments du plasma sanguin tout en bloquant les éléments formés comme les globules rouges et blancs. Nous discutons aussi de l'artériole afférente et efférente, qui alimentent et drainent le glomérule respectivement.
- 00:05:00 - 00:10:00
Les capillaires glomérulaires possèdent des pores fins, permettant le passage de petites molécules comme les protéines et électrolytes. Un élément clé est la membrane basale glomérulaire qui repousse les protéines chargées négativement. La membrane contient trois couches, dont la lamina densa constituée de collagène de type IV, jouant un rôle crucial dans la filtration.
- 00:10:00 - 00:15:00
La membrane basale résiste au passage des grandes molécules négativement chargées grâce à la charge négative des glycosaminoglycanes. Les molécules positives passent plus aisément la barrière. Les protéines plasmatiques comme l'albumine sont généralement repoussées. On examine comment cette membrane influence la filtration glomérulaire.
- 00:15:00 - 00:20:00
Les cellules podocytes de la capsule de Bowman forment des filtres supplémentaires appelés fentes de filtration, contrôlées par la protéine néphrine. Cela limite le passage des molécules de plus de 7-9 nm. Cela protège également contre la perte excessive de protéines, en constituant une barrière sélective.
- 00:20:00 - 00:25:00
Les cellules mésangiales jouent un rôle de soutien dans la structure glomérulaire et aident à phagocyter les macromolécules coincées. Elles ont aussi une activité contractile, régulant le flux sanguin et contribuant à la sécrétion de rénine qui affecte la pression artérielle.
- 00:25:00 - 00:30:00
La pression nette de filtration dépend des pressions glomérulaires hydrostatiques et colloïdale osmotiques. La PNF influence directement le taux de filtration glomérulaire (TFG), qui est d'environ 125 ml/min en conditions normales. Différents facteurs comme la tension artérielle systémique modifient ces pressions, affectant le TFG.
- 00:30:00 - 00:35:00
La surface et la perméabilité du glomérule affectent le TFG. Une plus grande surface filtrante et une plus haute perméabilité augmentent le TFG. Les conditions comme la néphropathie diabétique peuvent réduire la surface, diminuant le TFG. Le coefficient de filtration (KF) est crucial ici.
- 00:35:00 - 00:43:09
Les pressions comme la pression hydrostatique et la pression colloïde osmotique influencent fortement la filtration. Des scénarios cliniques comme l'hypertension ou les calculs rénaux peuvent augmenter ou diminuer ces pressions et altérer la filtration, impactant significativement la fonction rénale globale.
Mind Map
Video Q&A
Qu'est-ce qu'un corpuscule rénal ?
C'est une structure rénale composée de deux éléments : le glomérule et la capsule de Bowman.
Quels types de capillaires sont trouvés dans le glomérule ?
Les capillaires fenestrés.
À quoi servent les pores de fenestration ?
Ils permettent le passage de petites molécules, d'eau, d'électrolytes à travers les capillaires tout en bloquant les éléments formés comme les globules rouges et blancs.
Quelle est la fonction de la membrane basale glomérulaire ?
Elle agit comme un filtre supplémentaire en repoussant les protéines chargées négativement.
Comment les podocytes contribuent-ils à la filtration ?
Ils forment des fentes de filtration qui permettent uniquement le passage des particules très petites.
Qu'est-ce que la pression hydrostatique glomérulaire ?
C'est la force qui pousse le plasma hors des capillaires glomérulaires vers l'espace de Bowman.
Qu'est-ce que le taux de filtration glomérulaire (GFR) normal ?
Environ 125 ml/min.
Quel est l'effet de la pression sanguine sur le GFR ?
Une pression artérielle élevée augmente la pression hydrostatique glomérulaire, augmentant ainsi le GFR.
Pourquoi les protéines plasmatiques ne passent-elles pas dans l'urine ?
Elles sont repoussées par la charge négative de la membrane basale glomérulaire et des protéines des fentes de filtration.
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- 00:00:08all right ninine ND in this video we're
- 00:00:09going to specifically start talking
- 00:00:10about glamar filtration all right before
- 00:00:13we do that before we even get into glara
- 00:00:14filteration we have to look at the
- 00:00:16structure of something specific what is
- 00:00:18that structure that we have to talk
- 00:00:19about we have to talk about what's
- 00:00:20called a renal cor pusle okay so first
- 00:00:23off what is Arenal cor pusle let's
- 00:00:25actually Define what
- 00:00:26Arenal Corpus
- 00:00:31is so Roc cor pel is two things okay the
- 00:00:35first thing is actually the
- 00:00:38glomerulus okay which is capillaries
- 00:00:40which is a TFT of capillaries the other
- 00:00:44thing is the
- 00:00:47Bowman's
- 00:00:49capsule or sometimes they even call it
- 00:00:51the glomular capsule we're just going to
- 00:00:53call the Bowman's capsule okay so two
- 00:00:56components of the renal cor pusle again
- 00:00:58what are those two components of the
- 00:00:59Reno Cor pule the two components of the
- 00:01:01renal cor pusle is specifically the
- 00:01:05Glarus which is the tough de capillaries
- 00:01:08and the Bowman's
- 00:01:09capsule let's first talk about the
- 00:01:12glomerulus and the filtration membrane
- 00:01:14which is a part of it and then we'll
- 00:01:16talk about the Bowman's capsule okay so
- 00:01:18let's first focus on the Glarus so if
- 00:01:20you notice here this right here is the
- 00:01:21Glarus because this is the TFT of
- 00:01:23capillaries right here so a Glarus is
- 00:01:25like a tuft of capillaries and here's
- 00:01:27what's interesting if you notice let's
- 00:01:29say that this is the vessel coming into
- 00:01:31the Glarus so this is feeding into the
- 00:01:34Glarus when it goes into the Glarus it's
- 00:01:37actually called aparent
- 00:01:41arterial okay so if there's a vessel
- 00:01:43that's feeding in the glus it's called
- 00:01:44the aparent arterial and again this is
- 00:01:46the glus right here right here is their
- 00:01:48Glarus okay so we'll put that right
- 00:01:50above it this is our
- 00:01:53glus which is our TFT of capillaries oh
- 00:01:56what type of capillaries is there within
- 00:01:58the Glarus that's really really
- 00:01:59important you know it's type of
- 00:02:00capillaries are here in the Glarus
- 00:02:02they're actually called
- 00:02:06finr
- 00:02:08capillaries you know what finist strated
- 00:02:10capillaries means okay so let's say I
- 00:02:12take one of these endothelial
- 00:02:14cells and I zoom in on them so let's say
- 00:02:17here's an endothelial
- 00:02:19cell okay here's the nucleus of the
- 00:02:21endothelial cell in this endothelial
- 00:02:24cell it has little holes look at this
- 00:02:27you see this little hole right there
- 00:02:29little Channel basically that's a
- 00:02:32finestra there's another one over here
- 00:02:34too they have them all around these
- 00:02:36things there's hundreds upon hundreds
- 00:02:39maybe even thousands of these little
- 00:02:41finestra pores on this endothelial cell
- 00:02:46now these finestra pores what are they
- 00:02:48for let me explain to you what they're
- 00:02:50for well first off how big are these
- 00:02:52little things you know these little
- 00:02:53things right here these finra are
- 00:02:55approximately about 50 to 100 nanometers
- 00:02:58in diameter that's really really
- 00:03:00freaking small so about how much 50 to
- 00:03:03100
- 00:03:05nanometers in
- 00:03:07diameter so really what can actually
- 00:03:10filter through this okay you know within
- 00:03:11the blood you have your plasma which is
- 00:03:14consisting of a lot of water and
- 00:03:15different types of solute molecules
- 00:03:17right and then also you have formed
- 00:03:19elements like your white blood cells
- 00:03:20your red blood cells your
- 00:03:22plets any type of formed elements cannot
- 00:03:26fit through these finestra okay so any
- 00:03:29type of form form Med elements cannot
- 00:03:32fit through these actual fitration pores
- 00:03:35so formed elements are again what what
- 00:03:36are those components of formed elements
- 00:03:38red blood cells white blood cells
- 00:03:40platelets none of those can get in okay
- 00:03:43what can pass through the different
- 00:03:45components of the plasma so you know
- 00:03:47like small
- 00:03:49proteins small proteins can pass through
- 00:03:52this what else can pass through this
- 00:03:55water what else can pass through this
- 00:03:58electrolytes like sodium and potassium
- 00:04:01and calcium and chloride and a whole
- 00:04:03bunch of other different types of
- 00:04:04molecules a lot of different things okay
- 00:04:07and even
- 00:04:09nutrients waste products all different
- 00:04:11types of molecules can pass through
- 00:04:14these actual finestra pores okay so
- 00:04:17these fitration pores are basically
- 00:04:19riddled against all these little
- 00:04:20endothelial cells within the Glarus
- 00:04:22that's one important Point okay what is
- 00:04:25this structure draining the glomerulus
- 00:04:28here's a really really interesting watch
- 00:04:30this usually it's a vein right or a
- 00:04:33venil this is actually called the
- 00:04:36eant arterial this is one of the only
- 00:04:39examples in the
- 00:04:41body in which a capillary bed is being
- 00:04:44fed by an arterial and then drained by
- 00:04:47an arterial okay so we have aeren
- 00:04:50arterial feeding the Glarus we have an
- 00:04:52eeper arterial draining the Glarus and
- 00:04:54the Glarus is again fristrated
- 00:04:56capillaries what does it mean to be
- 00:04:57fitrated it's these little pores
- 00:05:00in the endothelial cell right that are
- 00:05:02about 50 to 100 nanm in diameter and
- 00:05:05what do they allow for things for it to
- 00:05:06pass through electrolytes nutrients
- 00:05:09small proteins water molecules and even
- 00:05:11maybe some large molecular weight
- 00:05:13proteins that are less than 100
- 00:05:15nanometers in diameter because if
- 00:05:17they're less than 100 nanometers in
- 00:05:18diameter they can pass through the
- 00:05:20actual fitration pores so let's even say
- 00:05:23not only small proteins but like we'll
- 00:05:24say
- 00:05:26moderate size
- 00:05:28proteins and again any proteins or any
- 00:05:31molecules that are about less than 100
- 00:05:34nanm in diameter can fit through these
- 00:05:35fitration pores
- 00:05:38now look at this little nice blue baby
- 00:05:42blue thing we have right here you see
- 00:05:45this blue membrane right here this is
- 00:05:47one of the most critical parts of the
- 00:05:49actual Glarus okay one of the most
- 00:05:52important points of the Glarus you know
- 00:05:54what this thing is actually called this
- 00:05:56blue membrane structure let's actually
- 00:05:57show it over here this blue membrane
- 00:05:59structure right here that we that I'm
- 00:06:00kind of showing here that I'm zooming in
- 00:06:02on right here this is actually called
- 00:06:04the glomular basement membrane so again
- 00:06:07what is it called the
- 00:06:09glomular
- 00:06:12basement membrane now some of you might
- 00:06:15be thinking okay it's just a basement
- 00:06:16membrane what what significance does
- 00:06:18that have oh my goodness so much
- 00:06:21significance okay this glar basement
- 00:06:24membrane is extremely interesting
- 00:06:26because if I were to let's say I
- 00:06:27actually zoomed in on even more let's
- 00:06:28say I even zoomed in the layer even more
- 00:06:30you know the GL base memory is actually
- 00:06:32three sub layers look at this let's say
- 00:06:35I zoom in on it for a second so here's
- 00:06:37the glomular basement membrane in the
- 00:06:40glomular basement membrane there's three
- 00:06:42layers let's say here in I make a black
- 00:06:44layer right there a real real thick
- 00:06:47black
- 00:06:48layer this thick black layer is actually
- 00:06:51going to be
- 00:06:53specifically consisting of type four
- 00:06:57collagen so what is this layer right
- 00:06:59here consisting of it's specifically
- 00:07:02consisting of type four
- 00:07:06collagen and laminins these different
- 00:07:09types of proteins okay so one is
- 00:07:12actually going to be type four collagen
- 00:07:14and if you notice it's really dense you
- 00:07:16know what they call this actual layer
- 00:07:17they call this the
- 00:07:20lamina
- 00:07:22denza okay so one layer right smack dab
- 00:07:25in the middle which is consisting of
- 00:07:26type four collagen and laminins is
- 00:07:28called the lamin den
- 00:07:30then let's say that this is the
- 00:07:32endothelial
- 00:07:34side and what do I mean by
- 00:07:37endothelial side I mean that here's your
- 00:07:40endothelial cells this part of the
- 00:07:42membrane closest to the endothelial
- 00:07:44cells is this side then you have these
- 00:07:46black cells which I'm going to talk
- 00:07:47about called the poyes that's going to
- 00:07:49be on this side so the poite I'm going
- 00:07:52to put pooy
- 00:07:55layer okay on this side here towards the
- 00:07:59endothelial cells it's a thinner like
- 00:08:02tissue okay it's a thinner layer this
- 00:08:05layer right here is actually made up of
- 00:08:08specific types of molecules like
- 00:08:11proteoglycans okay or
- 00:08:13glycosaminoglycans
- 00:08:14particularly Hein
- 00:08:17sulfate and guess what else you're going
- 00:08:19to find on the other side the same thing
- 00:08:23Hein sulfate these different types of
- 00:08:26glycos amino glycans now here's the next
- 00:08:29part that's really interesting Hein
- 00:08:31sulfate is extremely negatively charged
- 00:08:34okay so it's very very negatively
- 00:08:36charged so if I were to show that here
- 00:08:38let's say I show it here in Orange on
- 00:08:40this side what are you going to have a
- 00:08:41lot of negative charges what would you
- 00:08:44have on this side a lot of negative
- 00:08:46charges that's important I'm going to
- 00:08:48talk about that why that is now if I
- 00:08:50were to be particular this side is
- 00:08:52closest to the endothelial cell we call
- 00:08:54this side
- 00:08:56lamina Rara
- 00:09:00interna and then we call this side so
- 00:09:03that's laminar rare interna the one
- 00:09:04towards the endothelial lining the one
- 00:09:06on the opposite s towards the pooy
- 00:09:08lining is actually called the
- 00:09:10lamina
- 00:09:12Rara
- 00:09:14externa okay so the GLA basement
- 00:09:16membrane is actually three different
- 00:09:18sublayers one in the middle is actually
- 00:09:20the lamino denza with type four collagen
- 00:09:22and laminins lamin arera interna and
- 00:09:24lamin arera externa are consisting of
- 00:09:26Hein sulfate okay so a different type of
- 00:09:28glycos amino can which has a lot of
- 00:09:30negative charges on it why is this
- 00:09:33important
- 00:09:35okay you know inside of our blood we
- 00:09:38have these things called plasma proteins
- 00:09:41let's say I represent a plasma protein
- 00:09:43here as like
- 00:09:45albumin you know what abuin charge is
- 00:09:48inside of the blood generally or most
- 00:09:50plasma proteins it's negatively
- 00:09:55charged let's say I draw another plasma
- 00:09:57protein just for the heck of it I put in
- 00:09:59here here uh let's say I put in here um
- 00:10:02specifically different types of
- 00:10:04imunoglobulin so I'm going to put i g
- 00:10:07and we'll just be for the heck of it put
- 00:10:09IG
- 00:10:11immunoglobulins these are also
- 00:10:14negatively charged I could even put
- 00:10:15fibrinogen or different types of trans
- 00:10:17other type of transport proteins the
- 00:10:19whole point is proteins inside of our
- 00:10:21actual plasma are negatively charged
- 00:10:23what's the charge on this glomular
- 00:10:24basement membrane negative charge so
- 00:10:28it's very very negatively charge now if
- 00:10:30you know a little bit about biology you
- 00:10:31know that same charges repel one another
- 00:10:35so for example if I have albumin I
- 00:10:38represent albumin here as this circle
- 00:10:40and then all around him I have negative
- 00:10:42charges if he tries to come through this
- 00:10:44membrane or any type of molecule that's
- 00:10:45negatively charged tries to come through
- 00:10:47that membrane what's going to happen to
- 00:10:48it it's going to repel it so can I get
- 00:10:51through this actual glomular basement
- 00:10:53membrane no that's good at helping to
- 00:10:56act act as a good filter so now it's
- 00:10:59acting as a very good filter so any type
- 00:11:02of negatively charged particles that
- 00:11:04actually try to move through the
- 00:11:05glomular basement membrane is repelled
- 00:11:08but if you know again about biology what
- 00:11:11actually is going to want to come to the
- 00:11:14negative charge positively charged
- 00:11:16particles right so anything that's
- 00:11:17positively charged is going to want to
- 00:11:19come to the negative charges so any type
- 00:11:22of positive positively charge particles
- 00:11:24that we might
- 00:11:25have with inside of the plasma is going
- 00:11:28to want to what
- 00:11:29pass through
- 00:11:32here what are positively charged
- 00:11:34molecules usually different types of
- 00:11:36electrolytes like sodium and potassium
- 00:11:39and calcium and
- 00:11:41magnesium so that's really really
- 00:11:43interesting any type of positively
- 00:11:44charged substances are going to pass
- 00:11:45through the glomular basement membrane
- 00:11:47easily anything that's neutral it's
- 00:11:49going to be a little bit harder than
- 00:11:51positively charged species to pass
- 00:11:52through but it can still pass through
- 00:11:55any negatively charged species or
- 00:11:57different types of molecules are going
- 00:11:58to be repelled and prevented from
- 00:12:01entering into this actual glarin uh
- 00:12:03capsule here okay so if it's big enough
- 00:12:08like large molecular weight proteins or
- 00:12:10large different solute molecules and
- 00:12:11they move through the fenestration pores
- 00:12:14usually protein molecules are negatively
- 00:12:15charged so they'll be repelled by the
- 00:12:17glomular basement membrane so we have
- 00:12:19two barriers so far part of this
- 00:12:21filtration membrane so now we've
- 00:12:23developed what our Glarus is really made
- 00:12:24up of so let's actually write those two
- 00:12:26things out what are the two components
- 00:12:28one is actually the specifically the
- 00:12:33endothelial lining which is what finist
- 00:12:37strated guys remember that with the
- 00:12:38finestra pores which are approximately
- 00:12:40about 50 to 100 nanm in diameter which
- 00:12:43allow for certain things to pass through
- 00:12:45what's the other component of the Glarus
- 00:12:47the other component of the Glarus is the
- 00:12:50I'm just going to put glomular basement
- 00:12:52membrane GBM right and this is important
- 00:12:56because he has negatively charged
- 00:12:58surface which repels negatively charged
- 00:13:01particles so if you think about it like
- 00:13:02this negatively charged particles are
- 00:13:04repelled positively charged particles
- 00:13:06move through any neutral charge will
- 00:13:09also move through but not as readily as
- 00:13:11positively charged particles okay those
- 00:13:13are the two components of the glomerulus
- 00:13:15now what about the Bowman's capsule okay
- 00:13:18for the Bowman's
- 00:13:20capsule there's actually two different
- 00:13:24components one one is actually the
- 00:13:27parietal
- 00:13:31and the other one is the visceral layer
- 00:13:34but specifically these are your phocytes
- 00:13:37okay so now let's look at this okay so
- 00:13:41we talked about the Finish rate of
- 00:13:42capillary and ath helium we talked about
- 00:13:43the GL basement membrane now we're going
- 00:13:45to talk about the visceral layer of the
- 00:13:47Bowman's capsule specifically the poyes
- 00:13:50these poyes you know what poto actually
- 00:13:52means foot so it's foot cells so if you
- 00:13:53see at the end part it has these little
- 00:13:55little different foot processes okay
- 00:13:58these have in between the poyes so let's
- 00:14:01say here's a pooy so let's say this is
- 00:14:02pooy
- 00:14:04one and this is poite 2 poite 3 poite
- 00:14:08four poite 5 in between poite 1 and two
- 00:14:13there is a specific type of protein
- 00:14:18molecule look at this you see this it's
- 00:14:21kind of like inter connecting here so
- 00:14:23here's another one here's another one
- 00:14:25interconnecting here's another one
- 00:14:26between four and three interconnecting
- 00:14:30and here's one between four and five
- 00:14:32interconnecting you see what these
- 00:14:34little orange molecules are that are
- 00:14:35interconnecting our
- 00:14:36poyes this is actually called a very
- 00:14:39important protein I wouldn't be
- 00:14:40mentioning if it's not this molecule
- 00:14:41right here is actually this orange
- 00:14:42molecule is called
- 00:14:45nephrine now nephrine is important
- 00:14:48because there is certain types of uh
- 00:14:50conditions in glarin nefritis where you
- 00:14:52can actually have mutations within this
- 00:14:53nephrine protein why is that significant
- 00:14:56because you know nephrine is really
- 00:14:58really important for being able to
- 00:15:00control what's actually making it
- 00:15:02through what what so far would they have
- 00:15:03to go through to get to this point
- 00:15:05they'd have to go through the finra
- 00:15:07pores they'd have to make it through the
- 00:15:08negatively charged glomular basement
- 00:15:10membrane and then they have to get
- 00:15:12between these little things here what's
- 00:15:14this space right here called
- 00:15:16between the Poo sites here called what's
- 00:15:18that space there called that space
- 00:15:21between the Poo sites is actually called
- 00:15:23the
- 00:15:26filtration
- 00:15:27slit and a filtration slit is
- 00:15:31approximately 25 to 30 nanometers in
- 00:15:35diameter so now if it's made it through
- 00:15:38the fenestration pores if it's made it
- 00:15:40through the negatively charged glomular
- 00:15:41basement membrane and if it's less than
- 00:15:4325 nanometers approximately 25 to 30
- 00:15:46nmet in diameter it'll make it through
- 00:15:48but then guess what this nephrine
- 00:15:50proteins only allow for molecules
- 00:15:54anything that's actually 7 to 9
- 00:15:56nanometers in diameter or less to pass
- 00:16:00through okay nephrine is this protein
- 00:16:03molecule and he's actually forming this
- 00:16:06structure around so this space is the
- 00:16:07filtration slit but nephrine is kind of
- 00:16:09like a thin protein structure that's
- 00:16:11spanning that filtration slit and
- 00:16:13because it's spanning the filtration
- 00:16:15slit they call
- 00:16:17this the
- 00:16:20slit
- 00:16:23diaphragm okay so it's called the slit
- 00:16:26diaphragm and the Slit diaphragm is
- 00:16:28composed osed of nephrine and nephrine
- 00:16:30is only allowing for molecules that are
- 00:16:32less than 7 to9 nanm to be able to pass
- 00:16:35through this area okay then what do we
- 00:16:40have on the outside edges here we have
- 00:16:42the parietal layer of the Bowman's
- 00:16:44capsule so it's continuous with the
- 00:16:46visceral layer of Bowman's capsule so
- 00:16:49the poyes cling to the capillaries and
- 00:16:51it goes continuous with the prior layer
- 00:16:54of the bonus capsule to make a nice
- 00:16:56space so that anything that's filtering
- 00:16:57out isn't just lost it's collected into
- 00:17:00this nice little Bowman space here okay
- 00:17:03so what are the two components of the
- 00:17:04Bowman's capsule ready the pooy layer
- 00:17:07and has spaces in between the poyes
- 00:17:10which are called filtration slits and
- 00:17:12they're approximately 25 to 30
- 00:17:13nanometers in diameter and then has this
- 00:17:16protein molecule that are in between the
- 00:17:18phocytes linked together right and
- 00:17:21nephrine is the component of it it's
- 00:17:23it's making the slit diaphragm which is
- 00:17:25only allowing for molecules that are
- 00:17:27about less than 7 to 9 Nan to make it
- 00:17:29through this area okay so now let's go
- 00:17:32ahead and just kind of recap what can
- 00:17:34actually move through here because we
- 00:17:35kind of got a basis comp basic component
- 00:17:37of everything that's making up this Reno
- 00:17:39cor pusle let's cover what can make it
- 00:17:41through now okay so we can have plasma
- 00:17:44proteins let's just represent a as
- 00:17:46albumin IGG antibodies as another
- 00:17:48different type of protein let's
- 00:17:50represent our electrolytes like sodium
- 00:17:53uh potassium chloride what else would
- 00:17:56you have you'd have calcium you'd have
- 00:17:58magnesium magesium you can have
- 00:18:00bicarbonate tons of different molecules
- 00:18:02different types of actual uh electrolyte
- 00:18:04molecules right what else would you have
- 00:18:06over here you'd have
- 00:18:08glucose you'd have amino acids you'd
- 00:18:11have different types of lipids you'd
- 00:18:13have
- 00:18:14Ura uh different types of waste products
- 00:18:16right like uh even
- 00:18:18creatinine or creatinine which is a
- 00:18:20breakdown product of the muscle skeletal
- 00:18:22muscles from phosphate you'd have
- 00:18:24vitamins tons of different molecules in
- 00:18:26here right and what's one of the more
- 00:18:28important ones that we should definitely
- 00:18:30mention water all these are different
- 00:18:33molecules which are running through our
- 00:18:34plasma right and this isn't even all of
- 00:18:36them we could even have other things in
- 00:18:37there but again basic component is that
- 00:18:39you have electrolytes flowing through
- 00:18:41the plasma you have different types of
- 00:18:42nutrient sources and waste products
- 00:18:44flowing through the plasma you have
- 00:18:45water which is making up like 93% of the
- 00:18:48plasma and you have different types of
- 00:18:49plasma proteins okay albumin fibrinogen
- 00:18:53I could even put in there I could put in
- 00:18:54an F for fibrinogen if I needed to okay
- 00:18:57so there's fibrinogen and fibrin would
- 00:18:59also have negatively charged particles
- 00:19:01on it right different types of amino
- 00:19:03acids that make it negatively charged
- 00:19:05now out of these things what did I tell
- 00:19:07you can actually fit through the
- 00:19:08fenestration pores anything that's
- 00:19:10actually less than 50 to 100 nmet in
- 00:19:13diameter can pass right through so most
- 00:19:15of these substances can actually pass
- 00:19:17through but what did I tell you the
- 00:19:19glomular basement membrane has on it
- 00:19:21negatively charged particles so anything
- 00:19:24that's negatively charged like these
- 00:19:25actual what any of these plasma proteins
- 00:19:29are repelled this is repelled and this
- 00:19:32is repelled from what the glomular
- 00:19:34basement membrane what else did I tell
- 00:19:36you about the glamar basement membrane
- 00:19:38any type of positively charged particles
- 00:19:40are going to move through faster and
- 00:19:42easier than negatively charged particles
- 00:19:44so if you had to compare here bicarbon
- 00:19:46it would be a little bit harder to
- 00:19:47filter right as compared to sodium
- 00:19:50potassium calcium magnesium and chloride
- 00:19:52would be harder to filter as compared to
- 00:19:54potassium but nonetheless these
- 00:19:56substances are filtered
- 00:19:59so what would be filtered out here you
- 00:20:01would have it would actually move
- 00:20:03through the finestra pores through the
- 00:20:05glomular basement membrane and these
- 00:20:07particles as long as they're less than
- 00:20:09what at least 25 to 30 nmet in diameter
- 00:20:13as well as if they're less than 7 to 9
- 00:20:15nanometers in diameter what's going to
- 00:20:16come out here you're going to have
- 00:20:18bicarb you're going to have sodium
- 00:20:20you're going to have pottassium
- 00:20:22chloride calcium magnesium water's even
- 00:20:26going to be out here what else would be
- 00:20:28out here
- 00:20:29glucose amino acids lipids
- 00:20:34Ura creatinine all these different types
- 00:20:36of molecules are being filtered out look
- 00:20:40at all of these
- 00:20:41things all of these are being filtered
- 00:20:43out and again what do they want running
- 00:20:44through as a quick
- 00:20:46recap running through the fitration
- 00:20:48pores as long as they're uh less than 50
- 00:20:50to 100 nmet in diameter anything that's
- 00:20:52negatively charged is repelled by the
- 00:20:53glomular basement membrane they pass
- 00:20:56through the filtration slits which is
- 00:20:57about 25 to 30 nanm in diameter then
- 00:21:00there's the nephrine which is making up
- 00:21:01that slit diaphragm and as long as any
- 00:21:04particle is less than 7 to9 nanm in
- 00:21:06diameter it'll get freely filtered and
- 00:21:09what are those molecules that are most
- 00:21:11commonly freely filtered they are
- 00:21:14glucose amino acids lipids Ura
- 00:21:18creatinine different types of
- 00:21:19electrolytes even lactic acid and
- 00:21:22vitamins different types of molecules
- 00:21:24are filtered out and then where will
- 00:21:25they
- 00:21:26go they'll move out here into the actual
- 00:21:30what proximal convoluted tubal now one
- 00:21:33more thing before we go into these
- 00:21:35pressures
- 00:21:37okay let's say by some Chance some type
- 00:21:40of Macro Molecule gets through the
- 00:21:42fenestration pores gets through this
- 00:21:45actual glomular basement membrane and
- 00:21:47gets hung up in this filtration slit by
- 00:21:50the slit diaphragm what are we going to
- 00:21:52do with that it's just let's say it's
- 00:21:54actually dangling let's say here it is
- 00:21:55let's say somehow albumin is just
- 00:21:58freaking dangling from this thing okay
- 00:22:00like a monkey look what happens you see
- 00:22:03these cells right here these little like
- 00:22:05piranha looking cells they're getting
- 00:22:06ready to freck something up you know
- 00:22:08what these cells are called they're
- 00:22:10called mangial cells so what are these
- 00:22:11cells here called these little piranha
- 00:22:14looking
- 00:22:15cells they're called mangial
- 00:22:19cells now mangial
- 00:22:22cells are very very important to the
- 00:22:24glamar
- 00:22:25structure right because they have a
- 00:22:27couple different properties one one is
- 00:22:29they'll actually phagocytose any type of
- 00:22:31molecules that get hung up in that
- 00:22:33actual slit diaphragm which is composed
- 00:22:35of nephrine so that that guy right there
- 00:22:37he's going to come over and he's going
- 00:22:39to phagocytose any macromolecules that
- 00:22:41get stuck and hung up in that slit
- 00:22:43diaphragm you know what else he can do
- 00:22:46he also has contractile activity so he
- 00:22:48can contract contract what he can
- 00:22:51contract and control the amount of blood
- 00:22:52flow that's coming in through the aarin
- 00:22:54arterial and into the glara capillar
- 00:22:56we'll discuss that all also he has Gap
- 00:22:59Junctions Gap Junctions that connect him
- 00:23:02to these cells from other cells which
- 00:23:04are called the macula Denis cells what
- 00:23:06are these cells here called these little
- 00:23:09Violet or maroon cells they're called JG
- 00:23:13cells specifically
- 00:23:16juxa glomular
- 00:23:18cells if you remember these these are
- 00:23:21the ones that are producing renin and
- 00:23:24renin was important for our blood
- 00:23:26pressure right so they're actually
- 00:23:27Barrel receptors so pressure receptors
- 00:23:29they pick up different types of changes
- 00:23:31in pressure when the pressure is low
- 00:23:33they'll secrete renin and if you
- 00:23:34remember renin was important for being
- 00:23:36able to maintain our blood
- 00:23:38pressure okay and he can get signals
- 00:23:41from who pretend here was that mangial
- 00:23:44cell the mangial cell has little Gap
- 00:23:48Junctions that connect him to these
- 00:23:51actual JG cells and he can allow for
- 00:23:54different types of positively charged
- 00:23:56ions to come over here and stimulate him
- 00:23:58to release random we'll talk about that
- 00:24:00in the TU below glomular feedback
- 00:24:02mechanism Okay so we've covered a lot
- 00:24:05about the actual glomerulus and the
- 00:24:07Bowman's capsule and everything it can
- 00:24:09filter what allows for it to filter I
- 00:24:11think we've done pretty good on this now
- 00:24:13let's come over here and let's cover all
- 00:24:15the pressures that are involved in this
- 00:24:17what's actually allowing for this net
- 00:24:18filtration so what did I say net
- 00:24:21filtration so what are we going to talk
- 00:24:23about now we need to talk about the net
- 00:24:25filtration but you know nothing likes to
- 00:24:26move on its own it has to get a little
- 00:24:28bit of a push so you have to apply some
- 00:24:30pressure okay what is that called then
- 00:24:32we're going to talk about net filtration
- 00:24:35pressure because you know when we're
- 00:24:37talking about things that are being
- 00:24:38filtered it happens over a given period
- 00:24:41of time when something is being filtered
- 00:24:43over a given period of time and where is
- 00:24:45it occurring it's occurring in the
- 00:24:47glomerulus so there's what's called a
- 00:24:50glomular
- 00:24:52filtration rate so there's a glara
- 00:24:55filtration rate and generally we we
- 00:24:58describe Des rbe this is the amount of
- 00:25:00fluid that's actually being you know
- 00:25:02plasma volume that's actually being
- 00:25:04filtered out of the Glarus and into the
- 00:25:05Bowman's capsule for every 1 minute so
- 00:25:08we refer to this as the volume of plasma
- 00:25:12that's being filtered from the Glarus
- 00:25:14for every one minute on average that's
- 00:25:16about
- 00:25:17125 milliliters per minute now some of
- 00:25:21you might be like where the freck did
- 00:25:22that come from let me explain to
- 00:25:25you every about every 1
- 00:25:30minute okay there is approximately
- 00:25:341,200 milliliters of plasma flowing
- 00:25:37through the glara so for every 1 minute
- 00:25:401,200 milliliters is flowing through
- 00:25:43this area now out of that 1,200
- 00:25:49milliliters only
- 00:25:52625 milliliters per minute are going to
- 00:25:56be used in this filtration process so
- 00:25:581,00 milliliters per minute are passing
- 00:26:00through here but out of that 1200
- 00:26:02milliliters 625 are being used in the
- 00:26:05filtration process the remaining amount
- 00:26:08is passing by so now what's actually
- 00:26:10leaving then so 1 12200 is coming in 625
- 00:26:14is being going to be using this
- 00:26:15filtration process but 575
- 00:26:19milliliters per minute is actually going
- 00:26:21to be leaving out now here's what's the
- 00:26:23interesting part out of that
- 00:26:25625 milliliters per minute that you're
- 00:26:27actually going to be coming out of this
- 00:26:30here's what's
- 00:26:31crazy only 20% of it is actually going
- 00:26:35to be filtered okay so 1,200 Millers is
- 00:26:38passing through here 625 Millers we're
- 00:26:40going to use for this filtration process
- 00:26:42but out of that 625 Ms we're only going
- 00:26:44to really filter 20% of it how what is
- 00:26:4720% of
- 00:26:49625 that is actually 125 milliliters per
- 00:26:54minute okay that's where we get that
- 00:26:56glara filtration rate
- 00:26:58okay now that we've done that we know
- 00:27:02specifically how we get the glal
- 00:27:03filtration rate but now we got to talk
- 00:27:05about factors that are affecting the
- 00:27:07glome filtration weight what's actually
- 00:27:09affecting the glome filtration rate so
- 00:27:11in other words what can increase it what
- 00:27:13can decrease it so on and so forth okay
- 00:27:16so the first part of it is the net
- 00:27:18filtration
- 00:27:19pressure now net filtration pressure is
- 00:27:22consisting
- 00:27:24of the forces that are trying to push
- 00:27:27things out so
- 00:27:31pressures trying to push things so I'm
- 00:27:33going to put pressures uh forcing
- 00:27:37out okay so let's take a look at those
- 00:27:41pressures but then it's also dependent
- 00:27:44upon the difference of the pressures
- 00:27:45forcing things out
- 00:27:47minus the
- 00:27:50pressures pulling things in so
- 00:27:55pressures pulling
- 00:27:59in okay let's look at these two
- 00:28:02different components here because glal
- 00:28:04filtration rate is dependent upon this
- 00:28:06and something else that we'll talk about
- 00:28:07in a
- 00:28:08second okay so look at this first
- 00:28:11pressure this first pressure here is
- 00:28:14actually going to be called
- 00:28:16glomular
- 00:28:18hydrostatic
- 00:28:19pressure now glomular hydrostatic
- 00:28:22pressure is actually trying to push
- 00:28:26things out
- 00:28:29out of this
- 00:28:32capillary okay so he's trying to push
- 00:28:35things out of the
- 00:28:37capillary that's what glomular
- 00:28:39hydrostatic pressure is now generally as
- 00:28:42blood is flowing through here okay so
- 00:28:45let's say blood is flowing through the
- 00:28:46AER arterial right because this is the
- 00:28:48aarant arterial and this is the eer
- 00:28:51arterial when the blood is flowing
- 00:28:53through here the glomular hydrostatic
- 00:28:55pressure is defined as the pressure
- 00:28:57that's trying to p push the plasma
- 00:28:59components out of the capillary and into
- 00:29:02this actual Bowman space so that's what
- 00:29:06glomular hydrostatic pressure is it's
- 00:29:08defined as the actual forces that are
- 00:29:09trying to push the plasma the a specific
- 00:29:12volume of the plasma out of the Glam uh
- 00:29:15glomular capillaries into the Bowman
- 00:29:17space this number on average is about
- 00:29:2155 millimeters of mercury okay that's
- 00:29:26the average glamar hydrostatic pressure
- 00:29:29now there's another pressure there's a
- 00:29:32pressure that's exerted by specific
- 00:29:34types of plasma proteins like alumin
- 00:29:37albumin is trying to be able to keep
- 00:29:41things into the blood he doesn't want
- 00:29:44things to leave the blood okay so this
- 00:29:48is actually going to be a specific
- 00:29:49pressure and this pressure we're going
- 00:29:51to call colloid
- 00:29:54osmotic
- 00:29:56pressure and colloid osmotic pressure is
- 00:29:59exerted by plasma proteins that are
- 00:30:01being able to try to keep the water into
- 00:30:04the bloodstream so where is the arrow
- 00:30:06pointing it's trying to keep the actual
- 00:30:08water it prevent the water from leaving
- 00:30:10out into the space so keep it into the
- 00:30:12blood this colloid osmotic pressure is
- 00:30:15on average okay on average about
- 00:30:19specifically 30 millimet of mercury so
- 00:30:22about 30 millimeters of
- 00:30:26mercury okay
- 00:30:28so 30 millim of mercury for the colloid
- 00:30:30osmotic pressure and that's exerted by
- 00:30:33who
- 00:30:34albumin now there's one
- 00:30:36more as fluid is being filtered out here
- 00:30:40right think about it like a funnel so
- 00:30:42here's the fluid and it's trying to
- 00:30:44filter down into this little funnel
- 00:30:46right there as the fluid is trying to
- 00:30:48filter in through this area what happens
- 00:30:51if you try to pour a lot of fluid into a
- 00:30:53funnel at once what happens it overflows
- 00:30:55right same thing is happening here you
- 00:30:58start trying to push fluid out into this
- 00:31:00actual Bowman's capsule there's a narrow
- 00:31:02filtering process here so some of the
- 00:31:04fluid can start backing up and backing
- 00:31:06up and backing up and exert a pressure
- 00:31:08that wants to push things back into the
- 00:31:11actual capillary what is this pressure
- 00:31:13called that's trying to push
- 00:31:16things back
- 00:31:18into this capillary bed this right here
- 00:31:22is
- 00:31:23called capsular
- 00:31:26hydrostatic pressure this is called
- 00:31:30capsular hydrostatic pressure so the
- 00:31:33capsular hydrostatic pressure is the
- 00:31:35pressure that's being exerted by the
- 00:31:37actual pressured built up within the
- 00:31:39Bowman's capsule and as it's trying to
- 00:31:40drain there's a back pressure that tries
- 00:31:42to push fluid back into the actual glome
- 00:31:45capillaries and this on average is
- 00:31:49approximately 15 millimeters of
- 00:31:53mercury okay so now we have all of our
- 00:31:57our J B basically all these pressures
- 00:31:58that are pushing things out and all the
- 00:32:00pressures that are trying to pull or
- 00:32:02push things in technically there is one
- 00:32:04more pressure that I could mention here
- 00:32:06and it's it's zero though so it's not
- 00:32:09not really necessary to mention it but
- 00:32:11and the reason why is there's a pressure
- 00:32:13that you can can technically consider
- 00:32:14out here and then let's say there's
- 00:32:16there's a pressure trying to pull things
- 00:32:18into this
- 00:32:21actual Bowman's capsule that pressure
- 00:32:24would technically be called the capsular
- 00:32:26osmotic pressure pressure but what do we
- 00:32:30say as long as the filtration membrane
- 00:32:32is nice and actual kept intact and and
- 00:32:34it's not going to have any type of uh
- 00:32:36fluctuations in its activity there
- 00:32:38shouldn't be any type of plasma proteins
- 00:32:40out in this area so if there's no plasma
- 00:32:42proteins into this area can there really
- 00:32:44be any osmotic pressure out here no so
- 00:32:46normally the colloid osmotic pressure in
- 00:32:48this area is zero millimeters of mercury
- 00:32:51that's why we don't even really consider
- 00:32:53this one into the equation okay so now
- 00:32:55let's come over here and let's look and
- 00:32:56see what we got now
- 00:32:58so if we take the pressures trying to
- 00:33:00force things out or even if you
- 00:33:01technically think about it the cism
- 00:33:03modic pressure trying to pull things out
- 00:33:05what is the pressures Associated here so
- 00:33:07technically we could say the first
- 00:33:09pressure is the glomular hydrostatic
- 00:33:11pressure plus the capsular osmotic
- 00:33:14pressure technically right what was the
- 00:33:16glomular hydrostatic pressure it was
- 00:33:19approximately 55 millim of mercury and
- 00:33:24then what was the CID osmotic pressure
- 00:33:25it was
- 00:33:26approximately 0 millim of Brey right
- 00:33:29assuming normal activity what were the
- 00:33:32pressures that were trying to pull
- 00:33:34things in it was the colloid osmotic
- 00:33:38pressure right and that was actually
- 00:33:40trying to pull things in via the albumin
- 00:33:43then there was actually going to be the
- 00:33:45back pressure of the capsule trying to
- 00:33:47push things in which is called the
- 00:33:48capsular hydrostatic pressure what's the
- 00:33:51CID osmotic pressure on average is about
- 00:33:5330 millim of mercury plus the capsular
- 00:33:56hydrostatic pressure which is about 15
- 00:33:59mm of mercury if you do 55 minus
- 00:34:04approximately 45 what's your net
- 00:34:06filtration
- 00:34:08pressure 10 millime of
- 00:34:12mercury okay now from this we can derive
- 00:34:15a specific concept that due to these
- 00:34:18pressures any fluctuations in your net
- 00:34:20filtration pressure directly affects
- 00:34:22your glal filtration rate so in other
- 00:34:25words your net filtration pressure is
- 00:34:28directly proportional to your glomular
- 00:34:30filtration rate so in other words any
- 00:34:32increase in net filtration
- 00:34:34pressure increases your GFR any decrease
- 00:34:37in net filtration pressure decreases
- 00:34:40your GFR wow you developed a heck of a
- 00:34:42concept there right okay so there's two
- 00:34:44components here that are affecting this
- 00:34:46one is the surface area of the
- 00:34:51Glarus okay so surface area of the
- 00:34:53glomerulus that's one thing the other
- 00:34:57thing that going to determine this is
- 00:34:58also going to be specifically the
- 00:35:02permeability so the
- 00:35:07permeability of
- 00:35:11glomerulus okay so let's say I take two
- 00:35:14different types of gla one like
- 00:35:17this right so there's the apan arterial
- 00:35:19that's actually taking the blood in
- 00:35:21here's the eant arterial let's draw
- 00:35:24another one
- 00:35:25though okay now look at this puppy
- 00:35:29whoa aeren arterial eiren arterial
- 00:35:33what's the difference that you notice
- 00:35:34between these two this one has a very
- 00:35:36small surface area so he has a very
- 00:35:38small surface area there's not much
- 00:35:40surface area to act upon to filter so
- 00:35:43this will have a lower glomular
- 00:35:45filtration rate right because it has a
- 00:35:48smaller surface area but if you have a
- 00:35:50large surface area you have much more
- 00:35:52surface area for filtration so this
- 00:35:55would result in a greater glomular
- 00:35:57filtration rate that should be almost
- 00:36:00intuitive right that should make
- 00:36:02complete sense smaller the surface area
- 00:36:04the smaller the GFR the greater the
- 00:36:06surface area the greater the GFR simple
- 00:36:08as that what could change the surface
- 00:36:11area certain types of conditions could
- 00:36:13actually make it a little thicker you
- 00:36:14know there's actually a condition you've
- 00:36:16probably heard of it called diabetes but
- 00:36:18specifically it's called diabetic
- 00:36:23nephropathy and with di diabetic
- 00:36:25nephropathy there's actually protein and
- 00:36:27actual specific deposits in this actual
- 00:36:29Glarus that make it thicker and as you
- 00:36:30make it thicker it actually decreases
- 00:36:32the surface area which could affect the
- 00:36:34glara filtration rate but I'm just
- 00:36:35giving you a clinical correlation to
- 00:36:37surface area and how important it is for
- 00:36:39GL filtration rate okay so I say I take
- 00:36:42two different types of glami here let's
- 00:36:44say I take this one same surface area
- 00:36:46for both of them so look here's another
- 00:36:48one same surface area for this guy also
- 00:36:51but look at the difference here watch
- 00:36:53this let's say that this one only has
- 00:36:56one
- 00:36:59two three channels here to filter things
- 00:37:02out okay three channels while this one
- 00:37:05over here has
- 00:37:07one
- 00:37:092
- 00:37:113
- 00:37:124 five five channels on the same surface
- 00:37:17area what's going to happen to this
- 00:37:18guy's filtration rate this one will have
- 00:37:21a greater glara fitration rate right
- 00:37:23because he has a lot more permeability
- 00:37:26this one will have a low glara
- 00:37:28filtration rate because he has less
- 00:37:30permeability what kind of diseases could
- 00:37:32affect this you ever heard of glara
- 00:37:34nefritis so there's a condition called
- 00:37:38glomerulo
- 00:37:40nefritis and whenever there's damage to
- 00:37:42the Glarus it actually can affect the
- 00:37:44basement membrane and make the basement
- 00:37:46membrane very very uh it can actually
- 00:37:48destroy the basement membrane and make
- 00:37:49it very porous what happen to the GL
- 00:37:51filtration uh rate if the actual glome
- 00:37:54basement membrane was affected in very
- 00:37:56poor you would have a higher glal
- 00:37:58filtration rate and you would Lo lose a
- 00:37:59lot of proteins into the urine okay okay
- 00:38:01so now as an overall concept here if I
- 00:38:05were to take surface
- 00:38:08area and
- 00:38:10permeability of the actual capillaries
- 00:38:13and combine them together this actually
- 00:38:15gives me a specific term this term is
- 00:38:17called
- 00:38:19KF and KF stands for
- 00:38:23filtration coefficient
- 00:38:28okay so now I can actually derive one
- 00:38:30last formula that we need here we can
- 00:38:32say that glara filtration rate
- 00:38:34technically is equal to the net
- 00:38:36filtration pressure times the filtration
- 00:38:40coefficient because before we said that
- 00:38:42net filtration pressure is directly
- 00:38:44proportional to GFR increase in NFP
- 00:38:47increases GFR filtration coefficient is
- 00:38:50dependent upon surface area and
- 00:38:51permeability of the Glarus any
- 00:38:53fluctuations in the filtration
- 00:38:55coefficient also directly affect the
- 00:38:58glome infiltration rate one last thing
- 00:39:00here
- 00:39:02guys let's apply a clinical correlation
- 00:39:05to these actual net filtration pressure
- 00:39:07because I think that's it's significant
- 00:39:08okay so let's say that I take these
- 00:39:10three different pressures here the the
- 00:39:11most important ones the glamar
- 00:39:12hydrostatic
- 00:39:15pressure the uh colloid osmotic pressure
- 00:39:19here and then the capsular hydrostatic
- 00:39:22pressure what could be certain
- 00:39:24situations that could affect these
- 00:39:26things well I told before that glomular
- 00:39:28hydrostatic pressure is directly
- 00:39:30dependent upon your systemic blood
- 00:39:32pressure so if your BP is really high if
- 00:39:36your systemic blood pressure is high
- 00:39:37what happens to your your glomular
- 00:39:39hydrostatic pressure it increases your
- 00:39:42glomular hydrostatic pressure what
- 00:39:45happens if your BP goes down so what
- 00:39:47happens if you're having hypotension
- 00:39:48your glomular hydrostatic pressure goes
- 00:39:52down it's that simple okay so glomular
- 00:39:55hydrostatic pressure is directly
- 00:39:56dependent upon your systemic blood
- 00:39:58pressure an increase in blood pressure
- 00:40:00increases the GL hydrostatic pressure
- 00:40:02whereas a decrease decreases the GL
- 00:40:04hydrostatic pressure what about colloid
- 00:40:07osmotic
- 00:40:08pressure let's say that you actually
- 00:40:10have too many different types of
- 00:40:12proteins in the blood like there's a
- 00:40:14condition called multiple
- 00:40:16[Music]
- 00:40:18Myoma where you have too many different
- 00:40:20types of proteins in the blood if that
- 00:40:23happens what happens to the amount of
- 00:40:25proteins in the blood they go up if the
- 00:40:27amount amount of proteins in the blood
- 00:40:28go up you start holding on to more water
- 00:40:29in the blood if you hold on to a lot of
- 00:40:32water what happens the colloid osmotic
- 00:40:34pressure is going to increase right so
- 00:40:35this increases colloid osmotic pressure
- 00:40:38what happens if you have hypoproteinemia
- 00:40:41so low proteins in the blood so this
- 00:40:44could be due to maybe someone who's
- 00:40:45Gluten Sensitive and they decide to like
- 00:40:47Take and Eat house a pizza and what
- 00:40:49happens they don't feel good and they
- 00:40:50have the Hershey squirts right so they
- 00:40:51start losing a lot of substances right
- 00:40:55or maybe they have some type of actual
- 00:40:56disease maybe like they've infected by
- 00:40:58the Giardia and they lose a lot of
- 00:41:00proteins into their actual feces right
- 00:41:02so what happens then you lose proteins
- 00:41:04if you lose proteins can you hold on to
- 00:41:07as much water inside of the bloodstream
- 00:41:08no so what happens to your CID cosmotic
- 00:41:11pressure if you lose
- 00:41:13proteins this decreases colloid osmotic
- 00:41:16pressure and then what happens then you
- 00:41:18start losing fluids a lot more than
- 00:41:21normal into the actual Bowman
- 00:41:26space okay what about capsular
- 00:41:29hydrostatic pressure well let's say that
- 00:41:31you get like a freaking massive kidney
- 00:41:33stone stuck in your nefron Loop or
- 00:41:35something like that right so you get
- 00:41:37what's called a ren calculi that's
- 00:41:38greater than 5 millimeters in diameter
- 00:41:40and it gets stuck so a
- 00:41:42renal culi right so just a kidney stone
- 00:41:47greater than 5 millimeters in diameter
- 00:41:49so greater than 5 millimeters in
- 00:41:51diameter and it gets stuck in one of the
- 00:41:54actual nefron Loops let's say here's
- 00:41:55your nefron Loop
- 00:41:57and here's your actual Bowman's capsule
- 00:41:59if you have a stone stuck there what's
- 00:42:01going to happen to the pressure it's
- 00:42:04going to start backing up and it's going
- 00:42:05to start increasing and trying to push
- 00:42:07things back into the Glarus so what
- 00:42:08would that do to your capsular
- 00:42:09hydrostatic pressure if you had like a
- 00:42:11kidney stone it's going to increase your
- 00:42:14capsular hydrostatic pressure there's
- 00:42:16other conditions too like renalis when
- 00:42:19uh the individuals are really really
- 00:42:20emaciated they don't they lose a lot of
- 00:42:22weight rapid weight loss their kidneys
- 00:42:24drop and it Kinks up and fluid flows
- 00:42:26back into their kid it's called
- 00:42:28hydrosis that also can cause this
- 00:42:30problem too so not only can Roc culi do
- 00:42:33this but also
- 00:42:36Hydro nephrosis due to renal
- 00:42:41Tois okay this can also
- 00:42:45increase capsular hydrostatic pressure
- 00:42:48and then what would be the result of an
- 00:42:49increase in capsular hydrostatic
- 00:42:50pressure you would have more fluid being
- 00:42:52pushed back into the glami and not as
- 00:42:55much net filtration
- 00:42:57all right Ninja nerds we covered a lot
- 00:42:59in this video about GLA filtration thank
- 00:43:01you guys for sticking with us and
- 00:43:02watching this we really appreciate it I
- 00:43:04hope you guys enjoyed it I hope it all
- 00:43:06made sense until next time Ninja nerds
- filtration glomérulaire
- corpuscule rénal
- glomérule
- capsule de Bowman
- capillaires fenestrés
- membrane basale glomérulaire
- podocytes
- pression hydrostatique
- taux de filtration glomérulaire