Hi!
Welcome to our video series on Kidney Anatomy.
Now in this one, we're going to go back to the
very basics of your kidneys.
We're going to look at
the nephron,
the cortex,
the medulla,
and the capsule.
So, here you go
meet your kidneys.
I know that probably sounds weird
because you've been born with kidneys.
You've had them your whole life.
But I want to introduce you from a medical perspective.
Let's take a look at what these guys can do.
Now, they are mighty, bean-shaped organs, right?
They're about the size of your fist.
So do me a favor
and humor me,
put down your writing utensil for just a minute
and ball up both of your fists.
Now take a look at those.
That's about the actual side of the kidneys
that are located in your body.
Okay, you got it.
So here you have two of them about the size of your fist.
Let's talk about where they're located.
I want you to take those fists and move them behind your back.
Because they're located just one on either side of the spine.
Now, take your right fist.
Move it down a little bit lower down your back,
because that's how your real kidneys are.
Your right kidney is located a little bit lower
than your left kidney
because of the liver.
So that's how it kind of accommodates it.
So these two mighty bean-shaped organs
in your body are located
near the rear wall,
there on either side of your spine,
with the right one a little bit lower than your left.
Now, the major function of the kidneys.
We look at how they remove
excess fluid and waste products from your body.
So these little guys have some incredible super powers.
But for this video, we're going to focus on
excess fluid and waste product removal.
So now that we've reviewed the location of the kidneys,
I want to take a look at the layers of the kidney.
So let's get right down into the meat of the kidney.
The renal medulla
is near the innermost part of the kidney or the middle.
So, I remember that one as medulla, sounds like middle.
The next layer is the renal cortex.
Okay, so I've got the medulla in the middle,
and then I've got the cortex next.
Now there is an outer layer.
And I want you to see this on both drawings.
You see the drawing on the left as if we
sliced right through the kidney.
The drawing on the right is if we pull way back
and look at the kidney as being intact.
So, we've got the medulla,
you've got that it's in the middle.
Next, you have the cortex.
Finally, we're going to look at the renal capsule.
So see it on both drawings.
So, you've got the medulla in the very middle,
the cortex
and then the renal capsule.
Now after that, we get a little personal, right?
Because you've got this adipose capsule.
That's around the kidney. It's called the perirenal fat.
Now, I think of that as like perinatal,
and you have the little babies
and you want to hug them and hold them close.
But on this, I've got this layer of fat
around my kidneys
perirenal fat
and that helps to keep it protected.
Now, keep on moving outward.
Back up and review for just a minute.
Medulla,
cortex,
capsule,
then we have the perirenal fat,
then you've got the renal fascia,
followed by some
pararenal fat.
Okay, now this is not a slide you just want to
zip by.
You want to pause for a minute here and think,
can you put in order from renal medulla,
all the way up to pararenal fat?
So pause the video
and take a minute to make sure you have that all oriented
and you can fill that out
the steps from renal medulla to pararenal fat.
Now, nobody likes an extra layer of fat
but actually we need it to protect the kidneys.
There's three things I want you to keep in mind.
We talked about,
what are the structures that help to protect the kidneys?
You've got the capsule,
the perirenal fat,
and you've got the renal fascia.
So these structures are meant to cushion and protect our kidneys
from damage, from trauma, from being hit,
and absorbing shock.
So keeping in mind
three things that will keep your kidneys safe:
the capsule,
the fascia,
and the perirenal fat.
Let's break those down a little bit.
Now, the renal capsules is tough, fibrous connective tissue layer
that covers the outside of each kidney.
It's tough and fibrous
because it's made of collagen and elastin.
So you can see how that would be helpful.
It's this protective sack or case around your kidneys.
All right, I have a question for you.
How many liters of blood do kidneys filter per day?
Now, don't look ahead.
Just try and guesstimate what you think
how many liters of blood do your kidneys filter each day?
Yeah, pretty amazing.
142 liters of blood.
Now, I love Diet Mountain Dew.
And I usually get that in a two liter bottle.
That would be 71 bottles of Diet Mountain Dew.
That's a phenomenal amount of fluid
going through your kidneys every day.
But the cool part is
most of the water and other substances
that filter through my kidneys.
What do you think? They stay in or they go out?
Now they're returned to your blood by the tubules.
Only one to two liters actually become urine.
So I've got 142 liters racing through my kidneys,
but only one to two liters actually get peed out of my body as urine.
These really are incredible organs.