00:00
Now, let's take a look
deep into the kidney.
00:03
First of all,
reorient yourself.
00:05
You've got the medulla,
which is in the middle,
and then you've got
the cortex.
00:10
Now we kind of
blew that out.
00:12
If you see that we
- looks like we've got one
kind of pyramid
shaped there.
00:15
I want you to remember,
each kidney has
1 million nephrons.
00:20
So they're pretty densely packed
in there.
00:23
But we blew that up
and just showed you
a couple of the nephrons
to kind of give you the idea.
00:28
So look at that drawing.
00:29
Can you find the glomerulus?
Do you see Bowman's capsule?
And then do you see
both of the tubules?
Okay, great.
00:38
That's where they're located.
00:40
So we're looking at
just a couple
of the million nephrons
in each kidney.
00:45
We kind of blew that up
just to remind you
and to give you a refresher,
you've got the glomerulus
which is a tangle
of capillaries,
surrounded by the
Bowman's capsule,
and then you have
the tubules.
00:55
The three main parts
of the nephron.
00:58
Now we stretching this out
even farther.
01:01
Look at that middle line
across.
01:03
You see on the top is the cortex
below is the medulla
and the nephron is stretched
from the cortex
through to the medulla.
01:11
So just to give you an idea
of where you are in the kidney.
01:14
Now this to me is fascinating.
01:17
I know we might not be a
pharmacology nerd,
but look at
what was discovered.
01:21
We know exactly where the
sites of action are for diuretics
on the nephron.
01:27
So why are we talking about
diuretics with kidneys?
Because this is one of the biggest
areas of trouble for a patient
with kidney failure
or kidney problems.
01:36
They can't get rid
of that waste,
they can't get rid
of that volume.
01:40
So we use diuretics,
medications that will increase
how much of the fluid is
excreted from the body.
01:46
Now there they are
the PCT and the DCT.
01:50
You've got them right there.
01:51
The Proximal Convoluted Tubule
and
the Distal Convoluted Tubule.
01:55
Now here, first up,
about 65% to 70%
of the sodium
is reabsorbed there.
02:02
See the next one?
Sodium potassium,
you've got about 25% of it
absorbed there.
02:08
5% of the sodium chloride
is absorbed there,
and 1% to 5% of the sodium potassium
is reabsorbed there.
02:16
Okay, so notice the majority of that
gets absorbed at the beginning.
02:20
So you've got 65% to 70%.
02:23
Look at, follow it around
all the way to the end.
02:27
And you see we're down to
1% to 5%.
02:30
So progressively,
it gets lower.
02:32
You start at 65 to 70,
trace it around,
you go to 25,
then your at five
and then follow it
all the way out to the end
where you're at one to five.
02:42
Now this tells us
kind of lets us know how strong
or how potent a diuretic
is going to be
depending on where exactly
it works in the nephron.
02:52
Now, I've put the names up there
for you.
02:54
The 65% to 70% are the
Carbonic Anhydrase Inhibitors.
02:58
We call those CAIs
because that's a mouthful.
03:02
Next are the
loop diuretics.
03:04
Now you're probably
more familiar with those
Lasix or furosemide.
03:09
Now, these are the
strongest ones we use
for people in
renal failure.
03:13
We used to CAIs
for people with
eye problems,
but we're looking at
loop diuretics
that's predominantly
what you'll see prescribed
for people with
kidney disease,
or need to pull off extra fluid.
03:24
Next,
are the thiazides.
03:26
Now, both of these groups
have diuretics.
03:28
Loop diuretics and thiazides.
03:30
We'll really go after a patient's
potassium.
03:33
So keep that in mind.
03:35
Loop diuretics will cause the most
significant drop in potassium,
but thiazide diuretics
will also cause a drop in potassium.
03:42
Now finally,
we end up with
potassium sparing diuretics.
03:46
Toot-toot.
03:47
They're at the end of the line.
03:49
And that's why they're not
very intense.
03:52
We get our biggest impact
with most patients
with things like
the loop diuretics.
03:57
The potassium sparing diuretics
are used on special occasions
Or to help patients who are losing
too much potassium in treatment.
04:04
That's why they're called
potassium sparing diuretics.