Renal | Glomerular Filtration

00:43:09
https://www.youtube.com/watch?v=SVqSqPOcahY

Resumo

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.

Conclusões

  • 🧬 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.

Linha do tempo

  • 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.

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Mapa mental

Mind Map

Perguntas frequentes

  • 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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Legendas
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Rolagem automática:
  • 00:00:08
    all right ninine ND in this video we're
  • 00:00:09
    going to specifically start talking
  • 00:00:10
    about glamar filtration all right before
  • 00:00:13
    we do that before we even get into glara
  • 00:00:14
    filteration we have to look at the
  • 00:00:16
    structure of something specific what is
  • 00:00:18
    that structure that we have to talk
  • 00:00:19
    about we have to talk about what's
  • 00:00:20
    called a renal cor pusle okay so first
  • 00:00:23
    off what is Arenal cor pusle let's
  • 00:00:25
    actually Define what
  • 00:00:26
    Arenal Corpus
  • 00:00:31
    is so Roc cor pel is two things okay the
  • 00:00:35
    first thing is actually the
  • 00:00:38
    glomerulus okay which is capillaries
  • 00:00:40
    which is a TFT of capillaries the other
  • 00:00:44
    thing is the
  • 00:00:47
    Bowman's
  • 00:00:49
    capsule or sometimes they even call it
  • 00:00:51
    the glomular capsule we're just going to
  • 00:00:53
    call the Bowman's capsule okay so two
  • 00:00:56
    components of the renal cor pusle again
  • 00:00:58
    what are those two components of the
  • 00:00:59
    Reno Cor pule the two components of the
  • 00:01:01
    renal cor pusle is specifically the
  • 00:01:05
    Glarus which is the tough de capillaries
  • 00:01:08
    and the Bowman's
  • 00:01:09
    capsule let's first talk about the
  • 00:01:12
    glomerulus and the filtration membrane
  • 00:01:14
    which is a part of it and then we'll
  • 00:01:16
    talk about the Bowman's capsule okay so
  • 00:01:18
    let's first focus on the Glarus so if
  • 00:01:20
    you notice here this right here is the
  • 00:01:21
    Glarus because this is the TFT of
  • 00:01:23
    capillaries right here so a Glarus is
  • 00:01:25
    like a tuft of capillaries and here's
  • 00:01:27
    what's interesting if you notice let's
  • 00:01:29
    say that this is the vessel coming into
  • 00:01:31
    the Glarus so this is feeding into the
  • 00:01:34
    Glarus when it goes into the Glarus it's
  • 00:01:37
    actually called aparent
  • 00:01:41
    arterial okay so if there's a vessel
  • 00:01:43
    that's feeding in the glus it's called
  • 00:01:44
    the aparent arterial and again this is
  • 00:01:46
    the glus right here right here is their
  • 00:01:48
    Glarus okay so we'll put that right
  • 00:01:50
    above it this is our
  • 00:01:53
    glus which is our TFT of capillaries oh
  • 00:01:56
    what type of capillaries is there within
  • 00:01:58
    the Glarus that's really really
  • 00:01:59
    important you know it's type of
  • 00:02:00
    capillaries are here in the Glarus
  • 00:02:02
    they're actually called
  • 00:02:06
    finr
  • 00:02:08
    capillaries you know what finist strated
  • 00:02:10
    capillaries means okay so let's say I
  • 00:02:12
    take one of these endothelial
  • 00:02:14
    cells and I zoom in on them so let's say
  • 00:02:17
    here's an endothelial
  • 00:02:19
    cell okay here's the nucleus of the
  • 00:02:21
    endothelial cell in this endothelial
  • 00:02:24
    cell it has little holes look at this
  • 00:02:27
    you see this little hole right there
  • 00:02:29
    little Channel basically that's a
  • 00:02:32
    finestra there's another one over here
  • 00:02:34
    too they have them all around these
  • 00:02:36
    things there's hundreds upon hundreds
  • 00:02:39
    maybe even thousands of these little
  • 00:02:41
    finestra pores on this endothelial cell
  • 00:02:46
    now these finestra pores what are they
  • 00:02:48
    for let me explain to you what they're
  • 00:02:50
    for well first off how big are these
  • 00:02:52
    little things you know these little
  • 00:02:53
    things right here these finra are
  • 00:02:55
    approximately about 50 to 100 nanometers
  • 00:02:58
    in diameter that's really really
  • 00:03:00
    freaking small so about how much 50 to
  • 00:03:03
    100
  • 00:03:05
    nanometers in
  • 00:03:07
    diameter so really what can actually
  • 00:03:10
    filter through this okay you know within
  • 00:03:11
    the blood you have your plasma which is
  • 00:03:14
    consisting of a lot of water and
  • 00:03:15
    different types of solute molecules
  • 00:03:17
    right and then also you have formed
  • 00:03:19
    elements like your white blood cells
  • 00:03:20
    your red blood cells your
  • 00:03:22
    plets any type of formed elements cannot
  • 00:03:26
    fit through these finestra okay so any
  • 00:03:29
    type of form form Med elements cannot
  • 00:03:32
    fit through these actual fitration pores
  • 00:03:35
    so formed elements are again what what
  • 00:03:36
    are those components of formed elements
  • 00:03:38
    red blood cells white blood cells
  • 00:03:40
    platelets none of those can get in okay
  • 00:03:43
    what can pass through the different
  • 00:03:45
    components of the plasma so you know
  • 00:03:47
    like small
  • 00:03:49
    proteins small proteins can pass through
  • 00:03:52
    this what else can pass through this
  • 00:03:55
    water what else can pass through this
  • 00:03:58
    electrolytes like sodium and potassium
  • 00:04:01
    and calcium and chloride and a whole
  • 00:04:03
    bunch of other different types of
  • 00:04:04
    molecules a lot of different things okay
  • 00:04:07
    and even
  • 00:04:09
    nutrients waste products all different
  • 00:04:11
    types of molecules can pass through
  • 00:04:14
    these actual finestra pores okay so
  • 00:04:17
    these fitration pores are basically
  • 00:04:19
    riddled against all these little
  • 00:04:20
    endothelial cells within the Glarus
  • 00:04:22
    that's one important Point okay what is
  • 00:04:25
    this structure draining the glomerulus
  • 00:04:28
    here's a really really interesting watch
  • 00:04:30
    this usually it's a vein right or a
  • 00:04:33
    venil this is actually called the
  • 00:04:36
    eant arterial this is one of the only
  • 00:04:39
    examples in the
  • 00:04:41
    body in which a capillary bed is being
  • 00:04:44
    fed by an arterial and then drained by
  • 00:04:47
    an arterial okay so we have aeren
  • 00:04:50
    arterial feeding the Glarus we have an
  • 00:04:52
    eeper arterial draining the Glarus and
  • 00:04:54
    the Glarus is again fristrated
  • 00:04:56
    capillaries what does it mean to be
  • 00:04:57
    fitrated it's these little pores
  • 00:05:00
    in the endothelial cell right that are
  • 00:05:02
    about 50 to 100 nanm in diameter and
  • 00:05:05
    what do they allow for things for it to
  • 00:05:06
    pass through electrolytes nutrients
  • 00:05:09
    small proteins water molecules and even
  • 00:05:11
    maybe some large molecular weight
  • 00:05:13
    proteins that are less than 100
  • 00:05:15
    nanometers in diameter because if
  • 00:05:17
    they're less than 100 nanometers in
  • 00:05:18
    diameter they can pass through the
  • 00:05:20
    actual fitration pores so let's even say
  • 00:05:23
    not only small proteins but like we'll
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    say
  • 00:05:26
    moderate size
  • 00:05:28
    proteins and again any proteins or any
  • 00:05:31
    molecules that are about less than 100
  • 00:05:34
    nanm in diameter can fit through these
  • 00:05:35
    fitration pores
  • 00:05:38
    now look at this little nice blue baby
  • 00:05:42
    blue thing we have right here you see
  • 00:05:45
    this blue membrane right here this is
  • 00:05:47
    one of the most critical parts of the
  • 00:05:49
    actual Glarus okay one of the most
  • 00:05:52
    important points of the Glarus you know
  • 00:05:54
    what this thing is actually called this
  • 00:05:56
    blue membrane structure let's actually
  • 00:05:57
    show it over here this blue membrane
  • 00:05:59
    structure right here that we that I'm
  • 00:06:00
    kind of showing here that I'm zooming in
  • 00:06:02
    on right here this is actually called
  • 00:06:04
    the glomular basement membrane so again
  • 00:06:07
    what is it called the
  • 00:06:09
    glomular
  • 00:06:12
    basement membrane now some of you might
  • 00:06:15
    be thinking okay it's just a basement
  • 00:06:16
    membrane what what significance does
  • 00:06:18
    that have oh my goodness so much
  • 00:06:21
    significance okay this glar basement
  • 00:06:24
    membrane is extremely interesting
  • 00:06:26
    because if I were to let's say I
  • 00:06:27
    actually zoomed in on even more let's
  • 00:06:28
    say I even zoomed in the layer even more
  • 00:06:30
    you know the GL base memory is actually
  • 00:06:32
    three sub layers look at this let's say
  • 00:06:35
    I zoom in on it for a second so here's
  • 00:06:37
    the glomular basement membrane in the
  • 00:06:40
    glomular basement membrane there's three
  • 00:06:42
    layers let's say here in I make a black
  • 00:06:44
    layer right there a real real thick
  • 00:06:47
    black
  • 00:06:48
    layer this thick black layer is actually
  • 00:06:51
    going to be
  • 00:06:53
    specifically consisting of type four
  • 00:06:57
    collagen so what is this layer right
  • 00:06:59
    here consisting of it's specifically
  • 00:07:02
    consisting of type four
  • 00:07:06
    collagen and laminins these different
  • 00:07:09
    types of proteins okay so one is
  • 00:07:12
    actually going to be type four collagen
  • 00:07:14
    and if you notice it's really dense you
  • 00:07:16
    know what they call this actual layer
  • 00:07:17
    they call this the
  • 00:07:20
    lamina
  • 00:07:22
    denza okay so one layer right smack dab
  • 00:07:25
    in the middle which is consisting of
  • 00:07:26
    type four collagen and laminins is
  • 00:07:28
    called the lamin den
  • 00:07:30
    then let's say that this is the
  • 00:07:32
    endothelial
  • 00:07:34
    side and what do I mean by
  • 00:07:37
    endothelial side I mean that here's your
  • 00:07:40
    endothelial cells this part of the
  • 00:07:42
    membrane closest to the endothelial
  • 00:07:44
    cells is this side then you have these
  • 00:07:46
    black cells which I'm going to talk
  • 00:07:47
    about called the poyes that's going to
  • 00:07:49
    be on this side so the poite I'm going
  • 00:07:52
    to put pooy
  • 00:07:55
    layer okay on this side here towards the
  • 00:07:59
    endothelial cells it's a thinner like
  • 00:08:02
    tissue okay it's a thinner layer this
  • 00:08:05
    layer right here is actually made up of
  • 00:08:08
    specific types of molecules like
  • 00:08:11
    proteoglycans okay or
  • 00:08:13
    glycosaminoglycans
  • 00:08:14
    particularly Hein
  • 00:08:17
    sulfate and guess what else you're going
  • 00:08:19
    to find on the other side the same thing
  • 00:08:23
    Hein sulfate these different types of
  • 00:08:26
    glycos amino glycans now here's the next
  • 00:08:29
    part that's really interesting Hein
  • 00:08:31
    sulfate is extremely negatively charged
  • 00:08:34
    okay so it's very very negatively
  • 00:08:36
    charged so if I were to show that here
  • 00:08:38
    let's say I show it here in Orange on
  • 00:08:40
    this side what are you going to have a
  • 00:08:41
    lot of negative charges what would you
  • 00:08:44
    have on this side a lot of negative
  • 00:08:46
    charges that's important I'm going to
  • 00:08:48
    talk about that why that is now if I
  • 00:08:50
    were to be particular this side is
  • 00:08:52
    closest to the endothelial cell we call
  • 00:08:54
    this side
  • 00:08:56
    lamina Rara
  • 00:09:00
    interna and then we call this side so
  • 00:09:03
    that's laminar rare interna the one
  • 00:09:04
    towards the endothelial lining the one
  • 00:09:06
    on the opposite s towards the pooy
  • 00:09:08
    lining is actually called the
  • 00:09:10
    lamina
  • 00:09:12
    Rara
  • 00:09:14
    externa okay so the GLA basement
  • 00:09:16
    membrane is actually three different
  • 00:09:18
    sublayers one in the middle is actually
  • 00:09:20
    the lamino denza with type four collagen
  • 00:09:22
    and laminins lamin arera interna and
  • 00:09:24
    lamin arera externa are consisting of
  • 00:09:26
    Hein sulfate okay so a different type of
  • 00:09:28
    glycos amino can which has a lot of
  • 00:09:30
    negative charges on it why is this
  • 00:09:33
    important
  • 00:09:35
    okay you know inside of our blood we
  • 00:09:38
    have these things called plasma proteins
  • 00:09:41
    let's say I represent a plasma protein
  • 00:09:43
    here as like
  • 00:09:45
    albumin you know what abuin charge is
  • 00:09:48
    inside of the blood generally or most
  • 00:09:50
    plasma proteins it's negatively
  • 00:09:55
    charged let's say I draw another plasma
  • 00:09:57
    protein just for the heck of it I put in
  • 00:09:59
    here here uh let's say I put in here um
  • 00:10:02
    specifically different types of
  • 00:10:04
    imunoglobulin so I'm going to put i g
  • 00:10:07
    and we'll just be for the heck of it put
  • 00:10:09
    IG
  • 00:10:11
    immunoglobulins these are also
  • 00:10:14
    negatively charged I could even put
  • 00:10:15
    fibrinogen or different types of trans
  • 00:10:17
    other type of transport proteins the
  • 00:10:19
    whole point is proteins inside of our
  • 00:10:21
    actual plasma are negatively charged
  • 00:10:23
    what's the charge on this glomular
  • 00:10:24
    basement membrane negative charge so
  • 00:10:28
    it's very very negatively charge now if
  • 00:10:30
    you know a little bit about biology you
  • 00:10:31
    know that same charges repel one another
  • 00:10:35
    so for example if I have albumin I
  • 00:10:38
    represent albumin here as this circle
  • 00:10:40
    and then all around him I have negative
  • 00:10:42
    charges if he tries to come through this
  • 00:10:44
    membrane or any type of molecule that's
  • 00:10:45
    negatively charged tries to come through
  • 00:10:47
    that membrane what's going to happen to
  • 00:10:48
    it it's going to repel it so can I get
  • 00:10:51
    through this actual glomular basement
  • 00:10:53
    membrane no that's good at helping to
  • 00:10:56
    act act as a good filter so now it's
  • 00:10:59
    acting as a very good filter so any type
  • 00:11:02
    of negatively charged particles that
  • 00:11:04
    actually try to move through the
  • 00:11:05
    glomular basement membrane is repelled
  • 00:11:08
    but if you know again about biology what
  • 00:11:11
    actually is going to want to come to the
  • 00:11:14
    negative charge positively charged
  • 00:11:16
    particles right so anything that's
  • 00:11:17
    positively charged is going to want to
  • 00:11:19
    come to the negative charges so any type
  • 00:11:22
    of positive positively charge particles
  • 00:11:24
    that we might
  • 00:11:25
    have with inside of the plasma is going
  • 00:11:28
    to want to what
  • 00:11:29
    pass through
  • 00:11:32
    here what are positively charged
  • 00:11:34
    molecules usually different types of
  • 00:11:36
    electrolytes like sodium and potassium
  • 00:11:39
    and calcium and
  • 00:11:41
    magnesium so that's really really
  • 00:11:43
    interesting any type of positively
  • 00:11:44
    charged substances are going to pass
  • 00:11:45
    through the glomular basement membrane
  • 00:11:47
    easily anything that's neutral it's
  • 00:11:49
    going to be a little bit harder than
  • 00:11:51
    positively charged species to pass
  • 00:11:52
    through but it can still pass through
  • 00:11:55
    any negatively charged species or
  • 00:11:57
    different types of molecules are going
  • 00:11:58
    to be repelled and prevented from
  • 00:12:01
    entering into this actual glarin uh
  • 00:12:03
    capsule here okay so if it's big enough
  • 00:12:08
    like large molecular weight proteins or
  • 00:12:10
    large different solute molecules and
  • 00:12:11
    they move through the fenestration pores
  • 00:12:14
    usually protein molecules are negatively
  • 00:12:15
    charged so they'll be repelled by the
  • 00:12:17
    glomular basement membrane so we have
  • 00:12:19
    two barriers so far part of this
  • 00:12:21
    filtration membrane so now we've
  • 00:12:23
    developed what our Glarus is really made
  • 00:12:24
    up of so let's actually write those two
  • 00:12:26
    things out what are the two components
  • 00:12:28
    one is actually the specifically the
  • 00:12:33
    endothelial lining which is what finist
  • 00:12:37
    strated guys remember that with the
  • 00:12:38
    finestra pores which are approximately
  • 00:12:40
    about 50 to 100 nanm in diameter which
  • 00:12:43
    allow for certain things to pass through
  • 00:12:45
    what's the other component of the Glarus
  • 00:12:47
    the other component of the Glarus is the
  • 00:12:50
    I'm just going to put glomular basement
  • 00:12:52
    membrane GBM right and this is important
  • 00:12:56
    because he has negatively charged
  • 00:12:58
    surface which repels negatively charged
  • 00:13:01
    particles so if you think about it like
  • 00:13:02
    this negatively charged particles are
  • 00:13:04
    repelled positively charged particles
  • 00:13:06
    move through any neutral charge will
  • 00:13:09
    also move through but not as readily as
  • 00:13:11
    positively charged particles okay those
  • 00:13:13
    are the two components of the glomerulus
  • 00:13:15
    now what about the Bowman's capsule okay
  • 00:13:18
    for the Bowman's
  • 00:13:20
    capsule there's actually two different
  • 00:13:24
    components one one is actually the
  • 00:13:27
    parietal
  • 00:13:31
    and the other one is the visceral layer
  • 00:13:34
    but specifically these are your phocytes
  • 00:13:37
    okay so now let's look at this okay so
  • 00:13:41
    we talked about the Finish rate of
  • 00:13:42
    capillary and ath helium we talked about
  • 00:13:43
    the GL basement membrane now we're going
  • 00:13:45
    to talk about the visceral layer of the
  • 00:13:47
    Bowman's capsule specifically the poyes
  • 00:13:50
    these poyes you know what poto actually
  • 00:13:52
    means foot so it's foot cells so if you
  • 00:13:53
    see at the end part it has these little
  • 00:13:55
    little different foot processes okay
  • 00:13:58
    these have in between the poyes so let's
  • 00:14:01
    say here's a pooy so let's say this is
  • 00:14:02
    pooy
  • 00:14:04
    one and this is poite 2 poite 3 poite
  • 00:14:08
    four poite 5 in between poite 1 and two
  • 00:14:13
    there is a specific type of protein
  • 00:14:18
    molecule look at this you see this it's
  • 00:14:21
    kind of like inter connecting here so
  • 00:14:23
    here's another one here's another one
  • 00:14:25
    interconnecting here's another one
  • 00:14:26
    between four and three interconnecting
  • 00:14:30
    and here's one between four and five
  • 00:14:32
    interconnecting you see what these
  • 00:14:34
    little orange molecules are that are
  • 00:14:35
    interconnecting our
  • 00:14:36
    poyes this is actually called a very
  • 00:14:39
    important protein I wouldn't be
  • 00:14:40
    mentioning if it's not this molecule
  • 00:14:41
    right here is actually this orange
  • 00:14:42
    molecule is called
  • 00:14:45
    nephrine now nephrine is important
  • 00:14:48
    because there is certain types of uh
  • 00:14:50
    conditions in glarin nefritis where you
  • 00:14:52
    can actually have mutations within this
  • 00:14:53
    nephrine protein why is that significant
  • 00:14:56
    because you know nephrine is really
  • 00:14:58
    really important for being able to
  • 00:15:00
    control what's actually making it
  • 00:15:02
    through what what so far would they have
  • 00:15:03
    to go through to get to this point
  • 00:15:05
    they'd have to go through the finra
  • 00:15:07
    pores they'd have to make it through the
  • 00:15:08
    negatively charged glomular basement
  • 00:15:10
    membrane and then they have to get
  • 00:15:12
    between these little things here what's
  • 00:15:14
    this space right here called
  • 00:15:16
    between the Poo sites here called what's
  • 00:15:18
    that space there called that space
  • 00:15:21
    between the Poo sites is actually called
  • 00:15:23
    the
  • 00:15:26
    filtration
  • 00:15:27
    slit and a filtration slit is
  • 00:15:31
    approximately 25 to 30 nanometers in
  • 00:15:35
    diameter so now if it's made it through
  • 00:15:38
    the fenestration pores if it's made it
  • 00:15:40
    through the negatively charged glomular
  • 00:15:41
    basement membrane and if it's less than
  • 00:15:43
    25 nanometers approximately 25 to 30
  • 00:15:46
    nmet in diameter it'll make it through
  • 00:15:48
    but then guess what this nephrine
  • 00:15:50
    proteins only allow for molecules
  • 00:15:54
    anything that's actually 7 to 9
  • 00:15:56
    nanometers in diameter or less to pass
  • 00:16:00
    through okay nephrine is this protein
  • 00:16:03
    molecule and he's actually forming this
  • 00:16:06
    structure around so this space is the
  • 00:16:07
    filtration slit but nephrine is kind of
  • 00:16:09
    like a thin protein structure that's
  • 00:16:11
    spanning that filtration slit and
  • 00:16:13
    because it's spanning the filtration
  • 00:16:15
    slit they call
  • 00:16:17
    this the
  • 00:16:20
    slit
  • 00:16:23
    diaphragm okay so it's called the slit
  • 00:16:26
    diaphragm and the Slit diaphragm is
  • 00:16:28
    composed osed of nephrine and nephrine
  • 00:16:30
    is only allowing for molecules that are
  • 00:16:32
    less than 7 to9 nanm to be able to pass
  • 00:16:35
    through this area okay then what do we
  • 00:16:40
    have on the outside edges here we have
  • 00:16:42
    the parietal layer of the Bowman's
  • 00:16:44
    capsule so it's continuous with the
  • 00:16:46
    visceral layer of Bowman's capsule so
  • 00:16:49
    the poyes cling to the capillaries and
  • 00:16:51
    it goes continuous with the prior layer
  • 00:16:54
    of the bonus capsule to make a nice
  • 00:16:56
    space so that anything that's filtering
  • 00:16:57
    out isn't just lost it's collected into
  • 00:17:00
    this nice little Bowman space here okay
  • 00:17:03
    so what are the two components of the
  • 00:17:04
    Bowman's capsule ready the pooy layer
  • 00:17:07
    and has spaces in between the poyes
  • 00:17:10
    which are called filtration slits and
  • 00:17:12
    they're approximately 25 to 30
  • 00:17:13
    nanometers in diameter and then has this
  • 00:17:16
    protein molecule that are in between the
  • 00:17:18
    phocytes linked together right and
  • 00:17:21
    nephrine is the component of it it's
  • 00:17:23
    it's making the slit diaphragm which is
  • 00:17:25
    only allowing for molecules that are
  • 00:17:27
    about less than 7 to 9 Nan to make it
  • 00:17:29
    through this area okay so now let's go
  • 00:17:32
    ahead and just kind of recap what can
  • 00:17:34
    actually move through here because we
  • 00:17:35
    kind of got a basis comp basic component
  • 00:17:37
    of everything that's making up this Reno
  • 00:17:39
    cor pusle let's cover what can make it
  • 00:17:41
    through now okay so we can have plasma
  • 00:17:44
    proteins let's just represent a as
  • 00:17:46
    albumin IGG antibodies as another
  • 00:17:48
    different type of protein let's
  • 00:17:50
    represent our electrolytes like sodium
  • 00:17:53
    uh potassium chloride what else would
  • 00:17:56
    you have you'd have calcium you'd have
  • 00:17:58
    magnesium magesium you can have
  • 00:18:00
    bicarbonate tons of different molecules
  • 00:18:02
    different types of actual uh electrolyte
  • 00:18:04
    molecules right what else would you have
  • 00:18:06
    over here you'd have
  • 00:18:08
    glucose you'd have amino acids you'd
  • 00:18:11
    have different types of lipids you'd
  • 00:18:13
    have
  • 00:18:14
    Ura uh different types of waste products
  • 00:18:16
    right like uh even
  • 00:18:18
    creatinine or creatinine which is a
  • 00:18:20
    breakdown product of the muscle skeletal
  • 00:18:22
    muscles from phosphate you'd have
  • 00:18:24
    vitamins tons of different molecules in
  • 00:18:26
    here right and what's one of the more
  • 00:18:28
    important ones that we should definitely
  • 00:18:30
    mention water all these are different
  • 00:18:33
    molecules which are running through our
  • 00:18:34
    plasma right and this isn't even all of
  • 00:18:36
    them we could even have other things in
  • 00:18:37
    there but again basic component is that
  • 00:18:39
    you have electrolytes flowing through
  • 00:18:41
    the plasma you have different types of
  • 00:18:42
    nutrient sources and waste products
  • 00:18:44
    flowing through the plasma you have
  • 00:18:45
    water which is making up like 93% of the
  • 00:18:48
    plasma and you have different types of
  • 00:18:49
    plasma proteins okay albumin fibrinogen
  • 00:18:53
    I could even put in there I could put in
  • 00:18:54
    an F for fibrinogen if I needed to okay
  • 00:18:57
    so there's fibrinogen and fibrin would
  • 00:18:59
    also have negatively charged particles
  • 00:19:01
    on it right different types of amino
  • 00:19:03
    acids that make it negatively charged
  • 00:19:05
    now out of these things what did I tell
  • 00:19:07
    you can actually fit through the
  • 00:19:08
    fenestration pores anything that's
  • 00:19:10
    actually less than 50 to 100 nmet in
  • 00:19:13
    diameter can pass right through so most
  • 00:19:15
    of these substances can actually pass
  • 00:19:17
    through but what did I tell you the
  • 00:19:19
    glomular basement membrane has on it
  • 00:19:21
    negatively charged particles so anything
  • 00:19:24
    that's negatively charged like these
  • 00:19:25
    actual what any of these plasma proteins
  • 00:19:29
    are repelled this is repelled and this
  • 00:19:32
    is repelled from what the glomular
  • 00:19:34
    basement membrane what else did I tell
  • 00:19:36
    you about the glamar basement membrane
  • 00:19:38
    any type of positively charged particles
  • 00:19:40
    are going to move through faster and
  • 00:19:42
    easier than negatively charged particles
  • 00:19:44
    so if you had to compare here bicarbon
  • 00:19:46
    it would be a little bit harder to
  • 00:19:47
    filter right as compared to sodium
  • 00:19:50
    potassium calcium magnesium and chloride
  • 00:19:52
    would be harder to filter as compared to
  • 00:19:54
    potassium but nonetheless these
  • 00:19:56
    substances are filtered
  • 00:19:59
    so what would be filtered out here you
  • 00:20:01
    would have it would actually move
  • 00:20:03
    through the finestra pores through the
  • 00:20:05
    glomular basement membrane and these
  • 00:20:07
    particles as long as they're less than
  • 00:20:09
    what at least 25 to 30 nmet in diameter
  • 00:20:13
    as well as if they're less than 7 to 9
  • 00:20:15
    nanometers in diameter what's going to
  • 00:20:16
    come out here you're going to have
  • 00:20:18
    bicarb you're going to have sodium
  • 00:20:20
    you're going to have pottassium
  • 00:20:22
    chloride calcium magnesium water's even
  • 00:20:26
    going to be out here what else would be
  • 00:20:28
    out here
  • 00:20:29
    glucose amino acids lipids
  • 00:20:34
    Ura creatinine all these different types
  • 00:20:36
    of molecules are being filtered out look
  • 00:20:40
    at all of these
  • 00:20:41
    things all of these are being filtered
  • 00:20:43
    out and again what do they want running
  • 00:20:44
    through as a quick
  • 00:20:46
    recap running through the fitration
  • 00:20:48
    pores as long as they're uh less than 50
  • 00:20:50
    to 100 nmet in diameter anything that's
  • 00:20:52
    negatively charged is repelled by the
  • 00:20:53
    glomular basement membrane they pass
  • 00:20:56
    through the filtration slits which is
  • 00:20:57
    about 25 to 30 nanm in diameter then
  • 00:21:00
    there's the nephrine which is making up
  • 00:21:01
    that slit diaphragm and as long as any
  • 00:21:04
    particle is less than 7 to9 nanm in
  • 00:21:06
    diameter it'll get freely filtered and
  • 00:21:09
    what are those molecules that are most
  • 00:21:11
    commonly freely filtered they are
  • 00:21:14
    glucose amino acids lipids Ura
  • 00:21:18
    creatinine different types of
  • 00:21:19
    electrolytes even lactic acid and
  • 00:21:22
    vitamins different types of molecules
  • 00:21:24
    are filtered out and then where will
  • 00:21:25
    they
  • 00:21:26
    go they'll move out here into the actual
  • 00:21:30
    what proximal convoluted tubal now one
  • 00:21:33
    more thing before we go into these
  • 00:21:35
    pressures
  • 00:21:37
    okay let's say by some Chance some type
  • 00:21:40
    of Macro Molecule gets through the
  • 00:21:42
    fenestration pores gets through this
  • 00:21:45
    actual glomular basement membrane and
  • 00:21:47
    gets hung up in this filtration slit by
  • 00:21:50
    the slit diaphragm what are we going to
  • 00:21:52
    do with that it's just let's say it's
  • 00:21:54
    actually dangling let's say here it is
  • 00:21:55
    let's say somehow albumin is just
  • 00:21:58
    freaking dangling from this thing okay
  • 00:22:00
    like a monkey look what happens you see
  • 00:22:03
    these cells right here these little like
  • 00:22:05
    piranha looking cells they're getting
  • 00:22:06
    ready to freck something up you know
  • 00:22:08
    what these cells are called they're
  • 00:22:10
    called mangial cells so what are these
  • 00:22:11
    cells here called these little piranha
  • 00:22:14
    looking
  • 00:22:15
    cells they're called mangial
  • 00:22:19
    cells now mangial
  • 00:22:22
    cells are very very important to the
  • 00:22:24
    glamar
  • 00:22:25
    structure right because they have a
  • 00:22:27
    couple different properties one one is
  • 00:22:29
    they'll actually phagocytose any type of
  • 00:22:31
    molecules that get hung up in that
  • 00:22:33
    actual slit diaphragm which is composed
  • 00:22:35
    of nephrine so that that guy right there
  • 00:22:37
    he's going to come over and he's going
  • 00:22:39
    to phagocytose any macromolecules that
  • 00:22:41
    get stuck and hung up in that slit
  • 00:22:43
    diaphragm you know what else he can do
  • 00:22:46
    he also has contractile activity so he
  • 00:22:48
    can contract contract what he can
  • 00:22:51
    contract and control the amount of blood
  • 00:22:52
    flow that's coming in through the aarin
  • 00:22:54
    arterial and into the glara capillar
  • 00:22:56
    we'll discuss that all also he has Gap
  • 00:22:59
    Junctions Gap Junctions that connect him
  • 00:23:02
    to these cells from other cells which
  • 00:23:04
    are called the macula Denis cells what
  • 00:23:06
    are these cells here called these little
  • 00:23:09
    Violet or maroon cells they're called JG
  • 00:23:13
    cells specifically
  • 00:23:16
    juxa glomular
  • 00:23:18
    cells if you remember these these are
  • 00:23:21
    the ones that are producing renin and
  • 00:23:24
    renin was important for our blood
  • 00:23:26
    pressure right so they're actually
  • 00:23:27
    Barrel receptors so pressure receptors
  • 00:23:29
    they pick up different types of changes
  • 00:23:31
    in pressure when the pressure is low
  • 00:23:33
    they'll secrete renin and if you
  • 00:23:34
    remember renin was important for being
  • 00:23:36
    able to maintain our blood
  • 00:23:38
    pressure okay and he can get signals
  • 00:23:41
    from who pretend here was that mangial
  • 00:23:44
    cell the mangial cell has little Gap
  • 00:23:48
    Junctions that connect him to these
  • 00:23:51
    actual JG cells and he can allow for
  • 00:23:54
    different types of positively charged
  • 00:23:56
    ions to come over here and stimulate him
  • 00:23:58
    to release random we'll talk about that
  • 00:24:00
    in the TU below glomular feedback
  • 00:24:02
    mechanism Okay so we've covered a lot
  • 00:24:05
    about the actual glomerulus and the
  • 00:24:07
    Bowman's capsule and everything it can
  • 00:24:09
    filter what allows for it to filter I
  • 00:24:11
    think we've done pretty good on this now
  • 00:24:13
    let's come over here and let's cover all
  • 00:24:15
    the pressures that are involved in this
  • 00:24:17
    what's actually allowing for this net
  • 00:24:18
    filtration so what did I say net
  • 00:24:21
    filtration so what are we going to talk
  • 00:24:23
    about now we need to talk about the net
  • 00:24:25
    filtration but you know nothing likes to
  • 00:24:26
    move on its own it has to get a little
  • 00:24:28
    bit of a push so you have to apply some
  • 00:24:30
    pressure okay what is that called then
  • 00:24:32
    we're going to talk about net filtration
  • 00:24:35
    pressure because you know when we're
  • 00:24:37
    talking about things that are being
  • 00:24:38
    filtered it happens over a given period
  • 00:24:41
    of time when something is being filtered
  • 00:24:43
    over a given period of time and where is
  • 00:24:45
    it occurring it's occurring in the
  • 00:24:47
    glomerulus so there's what's called a
  • 00:24:50
    glomular
  • 00:24:52
    filtration rate so there's a glara
  • 00:24:55
    filtration rate and generally we we
  • 00:24:58
    describe Des rbe this is the amount of
  • 00:25:00
    fluid that's actually being you know
  • 00:25:02
    plasma volume that's actually being
  • 00:25:04
    filtered out of the Glarus and into the
  • 00:25:05
    Bowman's capsule for every 1 minute so
  • 00:25:08
    we refer to this as the volume of plasma
  • 00:25:12
    that's being filtered from the Glarus
  • 00:25:14
    for every one minute on average that's
  • 00:25:16
    about
  • 00:25:17
    125 milliliters per minute now some of
  • 00:25:21
    you might be like where the freck did
  • 00:25:22
    that come from let me explain to
  • 00:25:25
    you every about every 1
  • 00:25:30
    minute okay there is approximately
  • 00:25:34
    1,200 milliliters of plasma flowing
  • 00:25:37
    through the glara so for every 1 minute
  • 00:25:40
    1,200 milliliters is flowing through
  • 00:25:43
    this area now out of that 1,200
  • 00:25:49
    milliliters only
  • 00:25:52
    625 milliliters per minute are going to
  • 00:25:56
    be used in this filtration process so
  • 00:25:58
    1,00 milliliters per minute are passing
  • 00:26:00
    through here but out of that 1200
  • 00:26:02
    milliliters 625 are being used in the
  • 00:26:05
    filtration process the remaining amount
  • 00:26:08
    is passing by so now what's actually
  • 00:26:10
    leaving then so 1 12200 is coming in 625
  • 00:26:14
    is being going to be using this
  • 00:26:15
    filtration process but 575
  • 00:26:19
    milliliters per minute is actually going
  • 00:26:21
    to be leaving out now here's what's the
  • 00:26:23
    interesting part out of that
  • 00:26:25
    625 milliliters per minute that you're
  • 00:26:27
    actually going to be coming out of this
  • 00:26:30
    here's what's
  • 00:26:31
    crazy only 20% of it is actually going
  • 00:26:35
    to be filtered okay so 1,200 Millers is
  • 00:26:38
    passing through here 625 Millers we're
  • 00:26:40
    going to use for this filtration process
  • 00:26:42
    but out of that 625 Ms we're only going
  • 00:26:44
    to really filter 20% of it how what is
  • 00:26:47
    20% of
  • 00:26:49
    625 that is actually 125 milliliters per
  • 00:26:54
    minute okay that's where we get that
  • 00:26:56
    glara filtration rate
  • 00:26:58
    okay now that we've done that we know
  • 00:27:02
    specifically how we get the glal
  • 00:27:03
    filtration rate but now we got to talk
  • 00:27:05
    about factors that are affecting the
  • 00:27:07
    glome filtration weight what's actually
  • 00:27:09
    affecting the glome filtration rate so
  • 00:27:11
    in other words what can increase it what
  • 00:27:13
    can decrease it so on and so forth okay
  • 00:27:16
    so the first part of it is the net
  • 00:27:18
    filtration
  • 00:27:19
    pressure now net filtration pressure is
  • 00:27:22
    consisting
  • 00:27:24
    of the forces that are trying to push
  • 00:27:27
    things out so
  • 00:27:31
    pressures trying to push things so I'm
  • 00:27:33
    going to put pressures uh forcing
  • 00:27:37
    out okay so let's take a look at those
  • 00:27:41
    pressures but then it's also dependent
  • 00:27:44
    upon the difference of the pressures
  • 00:27:45
    forcing things out
  • 00:27:47
    minus the
  • 00:27:50
    pressures pulling things in so
  • 00:27:55
    pressures pulling
  • 00:27:59
    in okay let's look at these two
  • 00:28:02
    different components here because glal
  • 00:28:04
    filtration rate is dependent upon this
  • 00:28:06
    and something else that we'll talk about
  • 00:28:07
    in a
  • 00:28:08
    second okay so look at this first
  • 00:28:11
    pressure this first pressure here is
  • 00:28:14
    actually going to be called
  • 00:28:16
    glomular
  • 00:28:18
    hydrostatic
  • 00:28:19
    pressure now glomular hydrostatic
  • 00:28:22
    pressure is actually trying to push
  • 00:28:26
    things out
  • 00:28:29
    out of this
  • 00:28:32
    capillary okay so he's trying to push
  • 00:28:35
    things out of the
  • 00:28:37
    capillary that's what glomular
  • 00:28:39
    hydrostatic pressure is now generally as
  • 00:28:42
    blood is flowing through here okay so
  • 00:28:45
    let's say blood is flowing through the
  • 00:28:46
    AER arterial right because this is the
  • 00:28:48
    aarant arterial and this is the eer
  • 00:28:51
    arterial when the blood is flowing
  • 00:28:53
    through here the glomular hydrostatic
  • 00:28:55
    pressure is defined as the pressure
  • 00:28:57
    that's trying to p push the plasma
  • 00:28:59
    components out of the capillary and into
  • 00:29:02
    this actual Bowman space so that's what
  • 00:29:06
    glomular hydrostatic pressure is it's
  • 00:29:08
    defined as the actual forces that are
  • 00:29:09
    trying to push the plasma the a specific
  • 00:29:12
    volume of the plasma out of the Glam uh
  • 00:29:15
    glomular capillaries into the Bowman
  • 00:29:17
    space this number on average is about
  • 00:29:21
    55 millimeters of mercury okay that's
  • 00:29:26
    the average glamar hydrostatic pressure
  • 00:29:29
    now there's another pressure there's a
  • 00:29:32
    pressure that's exerted by specific
  • 00:29:34
    types of plasma proteins like alumin
  • 00:29:37
    albumin is trying to be able to keep
  • 00:29:41
    things into the blood he doesn't want
  • 00:29:44
    things to leave the blood okay so this
  • 00:29:48
    is actually going to be a specific
  • 00:29:49
    pressure and this pressure we're going
  • 00:29:51
    to call colloid
  • 00:29:54
    osmotic
  • 00:29:56
    pressure and colloid osmotic pressure is
  • 00:29:59
    exerted by plasma proteins that are
  • 00:30:01
    being able to try to keep the water into
  • 00:30:04
    the bloodstream so where is the arrow
  • 00:30:06
    pointing it's trying to keep the actual
  • 00:30:08
    water it prevent the water from leaving
  • 00:30:10
    out into the space so keep it into the
  • 00:30:12
    blood this colloid osmotic pressure is
  • 00:30:15
    on average okay on average about
  • 00:30:19
    specifically 30 millimet of mercury so
  • 00:30:22
    about 30 millimeters of
  • 00:30:26
    mercury okay
  • 00:30:28
    so 30 millim of mercury for the colloid
  • 00:30:30
    osmotic pressure and that's exerted by
  • 00:30:33
    who
  • 00:30:34
    albumin now there's one
  • 00:30:36
    more as fluid is being filtered out here
  • 00:30:40
    right think about it like a funnel so
  • 00:30:42
    here's the fluid and it's trying to
  • 00:30:44
    filter down into this little funnel
  • 00:30:46
    right there as the fluid is trying to
  • 00:30:48
    filter in through this area what happens
  • 00:30:51
    if you try to pour a lot of fluid into a
  • 00:30:53
    funnel at once what happens it overflows
  • 00:30:55
    right same thing is happening here you
  • 00:30:58
    start trying to push fluid out into this
  • 00:31:00
    actual Bowman's capsule there's a narrow
  • 00:31:02
    filtering process here so some of the
  • 00:31:04
    fluid can start backing up and backing
  • 00:31:06
    up and backing up and exert a pressure
  • 00:31:08
    that wants to push things back into the
  • 00:31:11
    actual capillary what is this pressure
  • 00:31:13
    called that's trying to push
  • 00:31:16
    things back
  • 00:31:18
    into this capillary bed this right here
  • 00:31:22
    is
  • 00:31:23
    called capsular
  • 00:31:26
    hydrostatic pressure this is called
  • 00:31:30
    capsular hydrostatic pressure so the
  • 00:31:33
    capsular hydrostatic pressure is the
  • 00:31:35
    pressure that's being exerted by the
  • 00:31:37
    actual pressured built up within the
  • 00:31:39
    Bowman's capsule and as it's trying to
  • 00:31:40
    drain there's a back pressure that tries
  • 00:31:42
    to push fluid back into the actual glome
  • 00:31:45
    capillaries and this on average is
  • 00:31:49
    approximately 15 millimeters of
  • 00:31:53
    mercury okay so now we have all of our
  • 00:31:57
    our J B basically all these pressures
  • 00:31:58
    that are pushing things out and all the
  • 00:32:00
    pressures that are trying to pull or
  • 00:32:02
    push things in technically there is one
  • 00:32:04
    more pressure that I could mention here
  • 00:32:06
    and it's it's zero though so it's not
  • 00:32:09
    not really necessary to mention it but
  • 00:32:11
    and the reason why is there's a pressure
  • 00:32:13
    that you can can technically consider
  • 00:32:14
    out here and then let's say there's
  • 00:32:16
    there's a pressure trying to pull things
  • 00:32:18
    into this
  • 00:32:21
    actual Bowman's capsule that pressure
  • 00:32:24
    would technically be called the capsular
  • 00:32:26
    osmotic pressure pressure but what do we
  • 00:32:30
    say as long as the filtration membrane
  • 00:32:32
    is nice and actual kept intact and and
  • 00:32:34
    it's not going to have any type of uh
  • 00:32:36
    fluctuations in its activity there
  • 00:32:38
    shouldn't be any type of plasma proteins
  • 00:32:40
    out in this area so if there's no plasma
  • 00:32:42
    proteins into this area can there really
  • 00:32:44
    be any osmotic pressure out here no so
  • 00:32:46
    normally the colloid osmotic pressure in
  • 00:32:48
    this area is zero millimeters of mercury
  • 00:32:51
    that's why we don't even really consider
  • 00:32:53
    this one into the equation okay so now
  • 00:32:55
    let's come over here and let's look and
  • 00:32:56
    see what we got now
  • 00:32:58
    so if we take the pressures trying to
  • 00:33:00
    force things out or even if you
  • 00:33:01
    technically think about it the cism
  • 00:33:03
    modic pressure trying to pull things out
  • 00:33:05
    what is the pressures Associated here so
  • 00:33:07
    technically we could say the first
  • 00:33:09
    pressure is the glomular hydrostatic
  • 00:33:11
    pressure plus the capsular osmotic
  • 00:33:14
    pressure technically right what was the
  • 00:33:16
    glomular hydrostatic pressure it was
  • 00:33:19
    approximately 55 millim of mercury and
  • 00:33:24
    then what was the CID osmotic pressure
  • 00:33:25
    it was
  • 00:33:26
    approximately 0 millim of Brey right
  • 00:33:29
    assuming normal activity what were the
  • 00:33:32
    pressures that were trying to pull
  • 00:33:34
    things in it was the colloid osmotic
  • 00:33:38
    pressure right and that was actually
  • 00:33:40
    trying to pull things in via the albumin
  • 00:33:43
    then there was actually going to be the
  • 00:33:45
    back pressure of the capsule trying to
  • 00:33:47
    push things in which is called the
  • 00:33:48
    capsular hydrostatic pressure what's the
  • 00:33:51
    CID osmotic pressure on average is about
  • 00:33:53
    30 millim of mercury plus the capsular
  • 00:33:56
    hydrostatic pressure which is about 15
  • 00:33:59
    mm of mercury if you do 55 minus
  • 00:34:04
    approximately 45 what's your net
  • 00:34:06
    filtration
  • 00:34:08
    pressure 10 millime of
  • 00:34:12
    mercury okay now from this we can derive
  • 00:34:15
    a specific concept that due to these
  • 00:34:18
    pressures any fluctuations in your net
  • 00:34:20
    filtration pressure directly affects
  • 00:34:22
    your glal filtration rate so in other
  • 00:34:25
    words your net filtration pressure is
  • 00:34:28
    directly proportional to your glomular
  • 00:34:30
    filtration rate so in other words any
  • 00:34:32
    increase in net filtration
  • 00:34:34
    pressure increases your GFR any decrease
  • 00:34:37
    in net filtration pressure decreases
  • 00:34:40
    your GFR wow you developed a heck of a
  • 00:34:42
    concept there right okay so there's two
  • 00:34:44
    components here that are affecting this
  • 00:34:46
    one is the surface area of the
  • 00:34:51
    Glarus okay so surface area of the
  • 00:34:53
    glomerulus that's one thing the other
  • 00:34:57
    thing that going to determine this is
  • 00:34:58
    also going to be specifically the
  • 00:35:02
    permeability so the
  • 00:35:07
    permeability of
  • 00:35:11
    glomerulus okay so let's say I take two
  • 00:35:14
    different types of gla one like
  • 00:35:17
    this right so there's the apan arterial
  • 00:35:19
    that's actually taking the blood in
  • 00:35:21
    here's the eant arterial let's draw
  • 00:35:24
    another one
  • 00:35:25
    though okay now look at this puppy
  • 00:35:29
    whoa aeren arterial eiren arterial
  • 00:35:33
    what's the difference that you notice
  • 00:35:34
    between these two this one has a very
  • 00:35:36
    small surface area so he has a very
  • 00:35:38
    small surface area there's not much
  • 00:35:40
    surface area to act upon to filter so
  • 00:35:43
    this will have a lower glomular
  • 00:35:45
    filtration rate right because it has a
  • 00:35:48
    smaller surface area but if you have a
  • 00:35:50
    large surface area you have much more
  • 00:35:52
    surface area for filtration so this
  • 00:35:55
    would result in a greater glomular
  • 00:35:57
    filtration rate that should be almost
  • 00:36:00
    intuitive right that should make
  • 00:36:02
    complete sense smaller the surface area
  • 00:36:04
    the smaller the GFR the greater the
  • 00:36:06
    surface area the greater the GFR simple
  • 00:36:08
    as that what could change the surface
  • 00:36:11
    area certain types of conditions could
  • 00:36:13
    actually make it a little thicker you
  • 00:36:14
    know there's actually a condition you've
  • 00:36:16
    probably heard of it called diabetes but
  • 00:36:18
    specifically it's called diabetic
  • 00:36:23
    nephropathy and with di diabetic
  • 00:36:25
    nephropathy there's actually protein and
  • 00:36:27
    actual specific deposits in this actual
  • 00:36:29
    Glarus that make it thicker and as you
  • 00:36:30
    make it thicker it actually decreases
  • 00:36:32
    the surface area which could affect the
  • 00:36:34
    glara filtration rate but I'm just
  • 00:36:35
    giving you a clinical correlation to
  • 00:36:37
    surface area and how important it is for
  • 00:36:39
    GL filtration rate okay so I say I take
  • 00:36:42
    two different types of glami here let's
  • 00:36:44
    say I take this one same surface area
  • 00:36:46
    for both of them so look here's another
  • 00:36:48
    one same surface area for this guy also
  • 00:36:51
    but look at the difference here watch
  • 00:36:53
    this let's say that this one only has
  • 00:36:56
    one
  • 00:36:59
    two three channels here to filter things
  • 00:37:02
    out okay three channels while this one
  • 00:37:05
    over here has
  • 00:37:07
    one
  • 00:37:09
    2
  • 00:37:11
    3
  • 00:37:12
    4 five five channels on the same surface
  • 00:37:17
    area what's going to happen to this
  • 00:37:18
    guy's filtration rate this one will have
  • 00:37:21
    a greater glara fitration rate right
  • 00:37:23
    because he has a lot more permeability
  • 00:37:26
    this one will have a low glara
  • 00:37:28
    filtration rate because he has less
  • 00:37:30
    permeability what kind of diseases could
  • 00:37:32
    affect this you ever heard of glara
  • 00:37:34
    nefritis so there's a condition called
  • 00:37:38
    glomerulo
  • 00:37:40
    nefritis and whenever there's damage to
  • 00:37:42
    the Glarus it actually can affect the
  • 00:37:44
    basement membrane and make the basement
  • 00:37:46
    membrane very very uh it can actually
  • 00:37:48
    destroy the basement membrane and make
  • 00:37:49
    it very porous what happen to the GL
  • 00:37:51
    filtration uh rate if the actual glome
  • 00:37:54
    basement membrane was affected in very
  • 00:37:56
    poor you would have a higher glal
  • 00:37:58
    filtration rate and you would Lo lose a
  • 00:37:59
    lot of proteins into the urine okay okay
  • 00:38:01
    so now as an overall concept here if I
  • 00:38:05
    were to take surface
  • 00:38:08
    area and
  • 00:38:10
    permeability of the actual capillaries
  • 00:38:13
    and combine them together this actually
  • 00:38:15
    gives me a specific term this term is
  • 00:38:17
    called
  • 00:38:19
    KF and KF stands for
  • 00:38:23
    filtration coefficient
  • 00:38:28
    okay so now I can actually derive one
  • 00:38:30
    last formula that we need here we can
  • 00:38:32
    say that glara filtration rate
  • 00:38:34
    technically is equal to the net
  • 00:38:36
    filtration pressure times the filtration
  • 00:38:40
    coefficient because before we said that
  • 00:38:42
    net filtration pressure is directly
  • 00:38:44
    proportional to GFR increase in NFP
  • 00:38:47
    increases GFR filtration coefficient is
  • 00:38:50
    dependent upon surface area and
  • 00:38:51
    permeability of the Glarus any
  • 00:38:53
    fluctuations in the filtration
  • 00:38:55
    coefficient also directly affect the
  • 00:38:58
    glome infiltration rate one last thing
  • 00:39:00
    here
  • 00:39:02
    guys let's apply a clinical correlation
  • 00:39:05
    to these actual net filtration pressure
  • 00:39:07
    because I think that's it's significant
  • 00:39:08
    okay so let's say that I take these
  • 00:39:10
    three different pressures here the the
  • 00:39:11
    most important ones the glamar
  • 00:39:12
    hydrostatic
  • 00:39:15
    pressure the uh colloid osmotic pressure
  • 00:39:19
    here and then the capsular hydrostatic
  • 00:39:22
    pressure what could be certain
  • 00:39:24
    situations that could affect these
  • 00:39:26
    things well I told before that glomular
  • 00:39:28
    hydrostatic pressure is directly
  • 00:39:30
    dependent upon your systemic blood
  • 00:39:32
    pressure so if your BP is really high if
  • 00:39:36
    your systemic blood pressure is high
  • 00:39:37
    what happens to your your glomular
  • 00:39:39
    hydrostatic pressure it increases your
  • 00:39:42
    glomular hydrostatic pressure what
  • 00:39:45
    happens if your BP goes down so what
  • 00:39:47
    happens if you're having hypotension
  • 00:39:48
    your glomular hydrostatic pressure goes
  • 00:39:52
    down it's that simple okay so glomular
  • 00:39:55
    hydrostatic pressure is directly
  • 00:39:56
    dependent upon your systemic blood
  • 00:39:58
    pressure an increase in blood pressure
  • 00:40:00
    increases the GL hydrostatic pressure
  • 00:40:02
    whereas a decrease decreases the GL
  • 00:40:04
    hydrostatic pressure what about colloid
  • 00:40:07
    osmotic
  • 00:40:08
    pressure let's say that you actually
  • 00:40:10
    have too many different types of
  • 00:40:12
    proteins in the blood like there's a
  • 00:40:14
    condition called multiple
  • 00:40:16
    [Music]
  • 00:40:18
    Myoma where you have too many different
  • 00:40:20
    types of proteins in the blood if that
  • 00:40:23
    happens what happens to the amount of
  • 00:40:25
    proteins in the blood they go up if the
  • 00:40:27
    amount amount of proteins in the blood
  • 00:40:28
    go up you start holding on to more water
  • 00:40:29
    in the blood if you hold on to a lot of
  • 00:40:32
    water what happens the colloid osmotic
  • 00:40:34
    pressure is going to increase right so
  • 00:40:35
    this increases colloid osmotic pressure
  • 00:40:38
    what happens if you have hypoproteinemia
  • 00:40:41
    so low proteins in the blood so this
  • 00:40:44
    could be due to maybe someone who's
  • 00:40:45
    Gluten Sensitive and they decide to like
  • 00:40:47
    Take and Eat house a pizza and what
  • 00:40:49
    happens they don't feel good and they
  • 00:40:50
    have the Hershey squirts right so they
  • 00:40:51
    start losing a lot of substances right
  • 00:40:55
    or maybe they have some type of actual
  • 00:40:56
    disease maybe like they've infected by
  • 00:40:58
    the Giardia and they lose a lot of
  • 00:41:00
    proteins into their actual feces right
  • 00:41:02
    so what happens then you lose proteins
  • 00:41:04
    if you lose proteins can you hold on to
  • 00:41:07
    as much water inside of the bloodstream
  • 00:41:08
    no so what happens to your CID cosmotic
  • 00:41:11
    pressure if you lose
  • 00:41:13
    proteins this decreases colloid osmotic
  • 00:41:16
    pressure and then what happens then you
  • 00:41:18
    start losing fluids a lot more than
  • 00:41:21
    normal into the actual Bowman
  • 00:41:26
    space okay what about capsular
  • 00:41:29
    hydrostatic pressure well let's say that
  • 00:41:31
    you get like a freaking massive kidney
  • 00:41:33
    stone stuck in your nefron Loop or
  • 00:41:35
    something like that right so you get
  • 00:41:37
    what's called a ren calculi that's
  • 00:41:38
    greater than 5 millimeters in diameter
  • 00:41:40
    and it gets stuck so a
  • 00:41:42
    renal culi right so just a kidney stone
  • 00:41:47
    greater than 5 millimeters in diameter
  • 00:41:49
    so greater than 5 millimeters in
  • 00:41:51
    diameter and it gets stuck in one of the
  • 00:41:54
    actual nefron Loops let's say here's
  • 00:41:55
    your nefron Loop
  • 00:41:57
    and here's your actual Bowman's capsule
  • 00:41:59
    if you have a stone stuck there what's
  • 00:42:01
    going to happen to the pressure it's
  • 00:42:04
    going to start backing up and it's going
  • 00:42:05
    to start increasing and trying to push
  • 00:42:07
    things back into the Glarus so what
  • 00:42:08
    would that do to your capsular
  • 00:42:09
    hydrostatic pressure if you had like a
  • 00:42:11
    kidney stone it's going to increase your
  • 00:42:14
    capsular hydrostatic pressure there's
  • 00:42:16
    other conditions too like renalis when
  • 00:42:19
    uh the individuals are really really
  • 00:42:20
    emaciated they don't they lose a lot of
  • 00:42:22
    weight rapid weight loss their kidneys
  • 00:42:24
    drop and it Kinks up and fluid flows
  • 00:42:26
    back into their kid it's called
  • 00:42:28
    hydrosis that also can cause this
  • 00:42:30
    problem too so not only can Roc culi do
  • 00:42:33
    this but also
  • 00:42:36
    Hydro nephrosis due to renal
  • 00:42:41
    Tois okay this can also
  • 00:42:45
    increase capsular hydrostatic pressure
  • 00:42:48
    and then what would be the result of an
  • 00:42:49
    increase in capsular hydrostatic
  • 00:42:50
    pressure you would have more fluid being
  • 00:42:52
    pushed back into the glami and not as
  • 00:42:55
    much net filtration
  • 00:42:57
    all right Ninja nerds we covered a lot
  • 00:42:59
    in this video about GLA filtration thank
  • 00:43:01
    you guys for sticking with us and
  • 00:43:02
    watching this we really appreciate it I
  • 00:43:04
    hope you guys enjoyed it I hope it all
  • 00:43:06
    made sense until next time Ninja nerds
Etiquetas
  • filtration glomérulaire
  • corpuscule rénal
  • glomérule
  • capsule de Bowman
  • capillaires fenestrés
  • membrane basale glomérulaire
  • podocytes
  • pression hydrostatique
  • taux de filtration glomérulaire