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students always ask
me um talk about renal blood flow i
always think of this as being
anatomy and then physio but then how do
you actually apply this into
what's going on in the clinical realm
well let's find out
renal blood flow to begin with just
simple
simple facts 20 of your cardiac output
kidney does that mean that the kidney is
that demanding
no it means that the kidney requires
plasma so that it can properly do what
conduct gfr that's it its main job
in its life is to filter plasma
now at each renault hilum where are you
you see where it says renal artery
arena artery is coming in to the hilum
of the kidney
whereas if it was a lung then you would
call that the hilum of the lung
now all of these are important things
and important anatomical uh
uh landmarks but let's continue forward
through the renal artery shall we
now as you branch your renal artery you
then get into your
interlobar and then you form your
arkwood see where it says arcuate
arc to it is exactly that it's an arc
now before i move any further i want to
make sure that you're
completely familiar with the just the
normal organization of the kidney
or really just any organ the medulla
will be the inner aspect the pulp
of the kidney or the organ and the
cortex will be the
outer aspect are we clear about that
okay do not ever
ever confuse those two and you you won't
so the medulla
has interesting structures in it that
you also want to pay attention to
the medulla the inner aspect the medulla
contains the pelvis it has the calluses
these are things that you know
from anatomy if you don't make sure that
you take a look at them
and it has something that we will
take a look at called the papilla
now before i repeat any of what i just
mentioned here
we then go into the arc look at the arc
the arc is the arch
over the pyramid and it gives rise to
your
cortical radiate arteries you see those
and the cortical radiate arteries well
technically called interlobular now
ultimately all of this is going to give
rise to afferent arterial you stop there
for
one second why because african arturia
as you know in physiology is incredibly
important
the afrin arterio is about to arrive to
whom
a afferent is about to a arrive
at which organ the glomerulus
what is it an afferent arteriola
you pay attention to that term versus
renal
artery why because as we
move forward and we start getting to
rhino vascular diseases
we are going to plug in pathologies into
the renal artery
and we already have for example
atherosclerosis
fibromuscular dysplasia and we're going
to put in
certain physiologic changes both in
pharmacology and as a reflex
in the afferent arterial and we'll bring
in
our juxtaglomeral apparatus that's a lot
of stuff going on at the afrin artorial
that you're familiar with and i'm not
overwhelming you i'm just telling you
things that you've seen before heard
before
all we're going to do is keep repeating
it
okay now pay attention here diabetes
and hypertension how common is that
really common
now i'm going to be technical so we'll
go ahead and call this diabetes mellitus
because we're in the la
we're in the realm of the kidney and
obviously there's another diabetes
differential is called diabetes
insipidus so now let's do mellitus and
hypertension
there are macrovascular diseases what do
we mean by that
resulting in progressive loss of these
vessels
meaning what the afferent arterials and
we then call this nephrosclerosis okay
so when we get to that point when we
start talking about kidney diseases in
greater detail
i will start asking you questions such
as well
where did we have issues first with
diabetes and it's in
what's it's the fact that you have blood
vessel issues
and we call this hyaline arthrosclerosis
as you shall see what kind hyaline
arterosclerosis
once again everything that we're doing
here is not just so that you can
memorize this stuff
it's so that you can take this
information and give a clinical
application isn't that why you and i are
here right now
now pathologically this change that
you're going to find
you then refer to this as your granular
surface
of the cortex what does that mean
a granular what does that mean rough
so because of the nephrosclerosis that
might be taking place
secondary to diabetes hypertension the
cortex of the kidney which is what the
superficial and that's why i stated this
from the get-go that the surface the
cortex
is undergoing granular changes and when
the time is right i'll show you pictures
of this as well
if there's anything else that you're
required to know here in terms of
anatomy
go ahead and take a look but i've given
you the important information that you
need to take out of this
for proper clinical application
go into the medulla what's going on
what's going on in the medulla
as we pass from the renal artery well
with the
medulla there might be certain issues
what kind of issues i want you to go
ahead and think about the
nephron and with the nephron i want you
to move down the proximal converted
tubule
are you moving down come on are you
there you with me i want you to produce
your urine
and as you produce your urine what are
you doing as you're going down the pct
you are especially the descending limb
you're removing more and more and more
of what
water right water permeable remember
that from physio
good as we move down into the nephron
and medulla what then happens
it means that you have uh hypertonic
fluid what's hypertonic mean it means
that you have increased concentrate and
solute
in the medulla that's exactly what you
have so
now as you move the thick ascending limb
there's an interesting pump there isn't
there and it's called the sodium
potassium two chloride remember that
from physio
well these are very very highly
metabolically active
you see the phrase metabolically active
so
say that you did have some type of
ischemic
event taking place once you have some
type of ischemic injury as stated here
then uh what do you think which part of
the
kidney is most susceptible to damage
because of the increased metabolic
activity in the medulla
such as a sodium potassium excuse me the
sodium potassium 2-chloride
symport and the fact that you have to go
in deep in the medulla
those are areas that are highly highly
susceptible to ischemic injury do not
forget that
move on now the blood supply the blood
supply to the tubular interstitial
tissue
where is that what is that even mean
well
in order for you to create a tubule
what's a tubule the nephron
in order for you to go from the renal
artery we just walked through
the arcuate talked about the afferent
arteriole giving rise
to your tuft of capillaries where am i
glomerulus and you're going to filter
filter what
plasma what's a structure that filters
plasma
i believe it's called what
good the glomerulus so correct me if i'm
wrong
do you first have to go through the
glomerulus
and then go into tubule or vice versa
have to go through the glomerus first
then the tubule what does that mean
read this the glomerulus which then
expresses the pathophysiologic changes
of tubular interstitial fibrosis so when
we get into
actual pathologies of the glomerulus and
tubular interstitial
nephritis your first issue is going to
be with the glomerulus and then you get
into
tubular interstitial diseases keep that
in mind when you get such questions
because
by the time you get into such pathology
i can almost guarantee you that you
probably already had damage to the
glomerulus
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you