can we now turn our attention to Reno
tubular defects and after this we're
gonna talk about renal tubular acidosis
so probably all of these are problems of
the renal tubules as you can tell for
their name so the first one is Fanconi
syndrome banco nice treatment we're
actually basically just going to go down
from proximal tubule and work away along
all the way around in tubules and see
all the problems that can occur so
proximal tubules has a problem that we
call Fanconi syndrome now Fanconi
syndrome is due to impaired reabsorption
that's one of the key functions of the
proximal cognitive of reabsorption of
water and different solids so if you
have impaired your sorption and pretty
much are basically every single solute
you have increased secretion all of
these and that includes things like
glucose phosphate and bicarb okay so
what effects are gonna happen when I was
when you think about is just think about
the acid base and electrolytes affected
for all the ones we're going to see and
especially we're gonna want to think
about potassium you're gonna want to
think about calcium that's pretty much
it and in this case in Fanconi syndrome
thinking about phosphate so what will
PHP will there be increased or decreased
blood pH that is will there be a
acidosis or in alkalosis that's the
question now as you can see there's
decreased reabsorption of bicarb so
you're gonna get an acidosis and what
this is it's gonna be a metabolic
acidosis from metabolic acidosis is when
acidosis results for me reno origin okay
so we ever get a metabolic acidosis do
the decrease by carbon absorption and
then I told you there's decreased
phosphate reabsorption so your PI pole
phosphate anemia and this can be a
problem because it can lead to
osteopenia and the reason for this is
you're gonna increase your bone
resorption to compensate for that low
phosphate you're gonna break down your
bone to increase blood phosphate but
that's gonna lead to weakening of your
bone and that's Austin Peay Nia okay
next is Bartter syndrome as you can see
Bartter syndrome
a problem with the loop of Henle here so
the next ones are offered all pretty
much gonna be problems with the main
transporter so Bartter syndrome the main
transport in the loop of Henle is the
sodium potassium to chloride eco
transporter
so what's gonna happen what effect what
effects you're gonna see and the easiest
way to think about this is what what
what drug do we give that makes it
pretty much the same effect what drug do
we give that makes a defect in this
transporter well if we give a loop
diuretic we're gonna block this
transporter so it's gonna look like the
same thing it's gonna have the same side
effects as that drug as the loop
diuretics so I told you look think about
the pH what will the pH be if you give
if you have Bartter syndrome remember
the same thing with loop diuretics
you're gonna get more sodium in the
collecting ducts that's gonna I say
they're only inside the collecting ducts
and they're gonna go out they're gonna
get really really gonna be to create it
in place H+ is gonna be secreted for
that charge balance you're gonna be
losing H+ so you're gonna get a
metabolic alkalosis okay same thing as
you see in the chronic in the loop
diuretic use we're gonna see increased
blood pH okay what will happen to the
potassium levels well it's only the same
idea again we're krama here but we also
get that potassium exchange for that
sodium so you need a hypokalemia okay
and then what about calcium I tell you
think about calcium as well how will
calcium change well remember in loop
diuretics loop diuretics will increase
urinary calcium and this cause decreased
calcium in the blood that's hypocalcemia
remember let's do that that decreased
potassium intake so let's decrease bath
leak until there's less calcium parasail
other reabsorption okay next is gilman
syndrome so get him on snare drum is in
the distal convoluted tubule and the
main transport here was that sodium
chloride transporter cochon
the distal convoluted to you so what
drug was it that blocked this
transporter rails the thiazide so it's
gonna look like chronic tires I'd use so
how was the pH gonna look like well
honestly patron died I took the rice to
do the same thing you increase the
sodium here so you're gonna get the same
I think you're gonna get metabolic
alkalosis you can get hypokalemia the
house calcium any change well this one
actually just only change this graph
let's go back how old calcium change in
thighs I'd use remember thighs Ides
block here we said DP sodium so now
there's gonna be increase of this sodium
going this way because it looks
concentration gradient so now we get
increased reabsorption to calcium okay
so if you get increased reabsorption of
calcium you get hypercalcemia here so
you can see Bartter syndrome get on and
soon you look pretty similar but the
main difference is that our assumption
gets hypocalcemia Gettleman syndrome
Katz hypercalcemia next one is little
syndrome to raise everything now little
syndrome there's two leave little
syndrome insane at the collecting tube
you'll see maybe Asian I'll tell you
what that means
little syndrome is due to over activity
of sodium reabsorption channel in the
collecting tubules so this sodium
channel is working extra much working
too much okay what what hormone is
responsible for activating this channel
through little hormone accidents
collecting duct for that sodium
reabsorption or it's aldosterone so this
is gonna be pretty much the same of
presentations hyperaldosteronism except
that aldosterone is pretty much
undetectable so same questions as as i
had before what is the ph what is the ph
and what's the K levels okay you too
much of this well you have to send back
H+ okay I didn't tell you gonna keep
seeing this again and again and
literally again and again so decrease H+
and blood
you have acidosis and then you have
decreased potassium and blood your
hypokalemia okay and then because you
were increasing so much of that sodium
reabsorption so so much sodium in your
extracellular fluid in your blood you
need a hypertension River sodium when
water is gonna follow a sodium and you
have all that sodium increased
osmolarity in the blood vessels in the
extracellular fluid so you're gonna get
increased blood volume increase blood
pressure blood pressure now how would
you treat this what was the diuretic
what was the medication that we used to
block that sodium channel we're the
medication acting the collecting ducts
to block that soda in China where the
potassium sparing diuretics and I told
you there's potassium sparing their next
diuretics that directly blocked the
channel and this prep had asked him
sparing directs that blocked the
aldosterone receptor so which one would
he use if you had to choose one remember
the fact that this is going to be
overactive a sodium channel so you don´t
even need aldosterone okay this is
overactive even without all dosterone so
if you're blocking that Ostrom receptor
it's still gonna be super overactive so
you need to directly block to that
sodium channel and the medication that
does this is a miller ID so a miller ID
is a potassium sparing the retic and
it's one of those that directly locks
that potassium channel and that's the
medication you need for little syndrome
alright finally we have seen which was
syndrome of a parent mineralocorticoid
excess and so this is due to overactive
mineral corticoid receptor so something
like aldosterone and that's due to
excess cortisol which activates the
receptor so I need to explain this in
the cell we normally have cortisol but
it's normal in cortisol activates this
receptor okay Cordova cortisol acts on
this receptor but in the cell there's
normally uh there's only an enzyme
called eleven beta hydroxy steroids
dehydrogenase you know just become and
recognize the name eleven
a hydroxy steroids dehydrogenase and I
will convert cortisol into cortisone and
cortisone does not act on this receptor
here okay
does not act on this receptor cortisol
does cortisol design okay but insane in
this syndrome this enzyme doesn't work
so you don't get cortisone you get the
court you just have you're stuck with
this cortisol which acts on this
receptor and it causes over activity
that's gonna be the same ideas little
syndrome you get too much of that sodium
reabsorption in exchange for her for the
H+ and the K so same presentation when
it present the same how the hell does it
present remember presence of acidosis
hypokalemia hypertension and the way you
treat this is you have two ways one you
seen it with potassium sparing diuretics
that block that mineral coracoid
receptor or you can give them
corticosteroids and what's gonna happen
why would you give steroids which is
basically cortisone because if you're
giving steroids it's all about that
feedback loop okay if you give steroids
you're gonna decrease endogenous
production of endogenous sort of
cortisol production so if you give
steroids in the blood you have a bunch
of steroids floating around the blood
they're gonna go there brain and they're
gonna shut off that cord at that a
steroid production so now there's gonna
be a decrease and dodging instructions
themselves of steroids so you take that
off okay so again present the same
little syndrome you train with potassium
spring diuretics or with steroids now
one last thing is how you remember all
these syndromes all these names are just
super confusing is think about an order
of the tubules
the first one is Fanconi so Fanconi is
first Fanconi first and after that the
rest of them are in alphabetical order
so next comes barter which is B next is
G and then finally a little L and same
so just you have to remember that fine
ponies first and then the rest go in
alphabetical order farther syndrome
gentleman seems a little bit little
Samuel and they're the same syndrome
okay
and these two are very similar these
have slight variations one is
overactivity of the channel itself one
is that overactivity of the receptors
which will activate the channel I also
want to add that there's these are many
different hereditary defects associated
with these two defects so it can be
autozone with the fact dominant
autosomal recessive above amenities
because I think they're pretty low yield
consult first aid if you really feel
like you need to memorize this and you
need to know everything okay now we go
to renal tubular acidosis and it's gonna
be a disorder of renal tubular exchange
leading to na Nana anion gap metabolic
acidosis okay so you can get acidosis
either in defects in your hydrogen
secretion or your bicarb reabsorption
okay now there's three people occasions
where this can happen first one is tight
as the distal you know tubular acidosis
so
distal the thing that happens when you
have h+ secretion okay and this is when
it fails if you do not have h plus
secretion while your alpha is your
killing cells and their collecting ducts
then h plus is gonna stay in the blood
vessels and it's gonna cause acidosis
now my question for you is well your
intake ph be high or low
well higher than normal or lower than
normal well it's gonna be higher than
normal and no one was gonna be around
five point less than five more five it's
gonna be higher than normal because
you're not getting h plus in that urine
so it's not gonna be acidified now my
other question is what will see your in
potassium B remember that sodium has to
go out but if this isn't happening what
how do we get sodium into the into the
plug we have to kick out potassium right
so you're gonna have decreased potassium
potassium user kicking a lot up passing
out into the tubules
because you can't exchange this H+ for
it that's the whole problem here
the second one is the proximal renal
tubular tubular acidosis so that's here
so would it be a problem with the H+
accretion or bicarbonate absorption
based on your knowledge of the renal
physiology well remember bicarb
reabsorption is what happens here so
would it be an over activation or a
failure well if it's an acidosis that
means you're not getting enough bicarb
until the blood so it's failure of
bicarb reabsorption in the proximal
convoluted tubule that's a proximal RTA
because it's proximal to the glomerulus
there's type 2 so how would you run PHP
and this one's a tricky one because you
might think there's extra body carbon in
urine so the urine pH is also gonna be
elevated but urine pH is actually less
than five point five because eventually
your urine is gonna it's going to be
basic for a while but it's gonna get
down here and in this case your Alpha
intercalated cells are working and
they're gonna be shooting h+ into the
urine and so you're gonna have a
decrease in your ph decrease know you're
in pH now what will the potassium levels
being this one's gonna be tricky to so
I'm gonna explain this to you if you a
failure of bicarb B absorption
approximately comment - guess what you
also have a deep ease reabsorption of
where that bicarb and sodium go together
so again you have to raise this all
again we have increased sodium that
makes it to the collecting duct because
there's decreased where a decreased
absorption of bicarb plus sodium so
again same as always you should be used
to this man so he goes in potassium goes
out so now your decrease okay finally
type 4 is called a hyperkalemic tubular
acidosis
hey mrs. Duda aldosterone deficiency or
resistance if you don't get all those
thrown deficiency there's less less of
this and then there's less of this are
also less of the H+ okay because of that
you're gonna have
why first first two units off on the
name is hyperkalemic so there's going to
be increased potassium in the blood and
it's because there's decreased secretion
so this is the hyperkalemic one and then
the urine pH your page will actually be
still less than five one five okay now
the way I remember this the easiest way
to remember this is to remember which
one's type one which one's type 2 which
was time for okay and there's gonna be a
night tonight not see for work mnemonic
here so if you're sensitive to anything
sexual please turn this off leave the
video you have two more seconds to leave
this video before I tell you so the
mnemonic here is for the distal proximal
and then aldosterone this deficiency or
resistance and this stands for a double
penetration anal okay if you already
know the orderlies you know the sequence
of these you know the type one is
distilled and you already know that
digital has to be a problem with H+
secretion because that's dis those where
H+ secretion happens and that's how you
get acidosis if you can't secrete it or
if you know that rock star the problem
is proximal then you know that proximal
the what goes on is the bicarb
reabsorption so you know if there's
acidosis it must be a problem in
reabsorbing bicarb
and finally if it's all dosterone then
it must be all doston resistance because
Dawson's wood kicks that H+ out so if
you have a sawed off the resistance H+
builds up again you get acidosis so just
remember that mnemonic if you're not too
offended by a double penetration anal
and then you'll know which ones type one
RTA what a type two RTA is what a type 4
RT is and that's all the problems of the
renal tubular tubules renal tubular
defects we know tubular acidosis