What is emphysema? | Respiratory system diseases | NCLEX-RN | Khan Academy

Voiceover: It's such a
mouthful to say chronic

obstructive pulmonary
disease, so since there's

an acronym for everything
we just call this COPD.

Chronic means it develops and happens

over a long, long period of time.

Pulmonary disease means
it happens in the lungs.

But obstructive is
really the key word here,

and we'll come back to
this in just a second

to describe exactly
what's obstructed here.

But first let's draw some airways.

You have your trachea, that's
where air enters the airway.

To me the whole thing looks
kind of like an upside down tree

where you have these branches
that keep branching off.

There's 20 or 30 branches,
I can't draw them all,

but you can imagine it
just keeps getting smaller

and smaller, just like
branches on a real tree.

As they get to the end of a unit here,

let me draw it where there's more space,

we encounter something that
kind of looks like this,

it's kind of like a
cluster of little bubbles.

We call this the alveoli cluster.

Alveoli is plural for alveolus.

It's a Latin thing to make the
plural into an -i at the end.

All of these are alveoli.

In fact, aside from the
cluster at the end they

happen around on the
stem near the end of the

cluster as well, kind
of on the tree branch.

To get into the nitty-gritty,

this is where emphysema happens.

Let's just blow up that end unit

there and get a better look.

You have your terminal branch here.

The way I'm drawing this kind of looks

like little clusters of tents.

You'll see in just a second why I'm

drawing it in particular like this.

I'm trying to get across
the idea that there are

walls separating each
alveolus from each other.

The walls have alveoli and
at end you have your cluster.

This is what the whole
thing looks like at the

top of the breath when
it's filled with air.

I'm really tempted to
compare this to a balloon

that's blowing up, but we have to keep in

mind that the comparison between lungs and

balloons only exist during expiration.

In a second we'll see what
happens during expiration

but first, just to be
clear, let me explain why

it's only expiration
that's like a balloon.

When you have a balloon,

this is your regular balloon
and you have air going in,

usually there's positive
pressure out here putting air in.

Either you're blowing
into it or it's hooked up

to a machine or something
and that's how air gets in.

But in the lungs during inspiration,

nothing is blowing into your
mouth forcing the air in.

The air comes in by a
negative pressure inside.

The way that happens is
because our chest wall,

it's kind of like a box
outside the balloon.

It expands with muscles,
and as they expand it

takes the walls of the balloon with it,

and that negative pressure
is how air goes in.

But we're really not concerned
with inspiration right

now because obstructive
diseases are expiratory.

Regardless of how the air got
in there we can start thinking

of it exactly like a balloon
at the top of a breath now.

When you let a balloon go the
air just rushes right out,

it's the same thing in your lungs.

As soon as you relax the walls
of this airway pushes the

air out, because the
wonderful protein that we call

elastin that makes up the
structure of these walls.

Whoever named this really thought
it through because elastin

describes the fact that it's
elastic, like a rubber band.

As soon as the lungs relax
these walls snap back

to their regular size, kind of like this.

Not very much air inside
at all, because the recoil

strength of these walls
pushes the air out.

Now in COPD what happens is
this elastin gets destroyed.

I just said that elastin
gives the elastic quality

of the walls, so when
that's gone, the elastic

quality of these partitionings
that hold their structure,

that give their recoil strength,
that's all gone as well.

Instead of looking like a
perky balloon animal with all

these shapes, I think
of a lung that has COPD,

or this same structure, same
unit of the lung that has COPD,

kind of looks like this
amorphous blob because the walls

have lost their structure,
they've lost their recoil

strength, so they don't
hold their original shape.

It's kind of floppy, kind of like

a plastic bag instead of a balloon.

When you have a plastic bag and you

let it go air does not rush out,

there's no recoil strength
making the walls snap back.

It kind of just stays
here and nothing happens.

That's the first step, and
to make matters worse in

emphysema, what happens
is here in the stem of the

airway this area actually
collapses and forms

a physical obstruction
to the air coming out.

The reason that happens,
I kind of like to think

of it as what happens
when you have an open

door in your house and
it's a windy day or breezy.

As the wind goes through this open airway

sometimes the door just shuts with it,

and you hear this loud, it
suddenly pulls the door shut.

It's kind of the same
thing, that as air is trying

to get out here it
pulls the walls with it.

Usually there's elastin and
structure to the walls so this

remains open, but here without
all that the walls just

want to go with the air,
such that it collapses here.

Now you have all these air
behind it that cannot get out.

Not only are the walls not pushing it

out but now you have a closed door.

These things combined together is

what gives you obstructed disease.

COPD technically refers
to two different diseases.

There's emphysema, which is
what we're talking about today,

with elastin destruction, and
there's chronic bronchitis.

Anything -itis just means inflammation or

irritation to an area,
the airway is irritated.

Depending on how this person
got the disease a lot of

times these two variations
of COPD can exist together

in one person, but today
we're just talking about

emphysema in terms of elastin destruction.

Okay, so where were we.

We talked about how there's all this extra

air in here that cannot escape your lungs.

You might think, "So
what? I work all day to

"get air into my lungs,
that's the whole point,"

and you would be half correct.

If we imagine that there's
a blood supply here,

I mean the blood supply
in the airways go together

because they need to
form an exchange system.

Oxygen is usually in the lungs
that we pulled from the air,

so oxygen goes into our
blood stream making it red.

Then the other half of the deal
is that we have carbon dioxide

that the blood brings to
the lung to get rid of.

These are made by our tissues after

they've used up the oxygen.

It's kind of like a waste product.

This needs to go back into the lungs and

out through our mouth, and this exchange

is really the complete job of our lungs.

With obstructed disease
you can do half of it.

You can put oxygen in but if
you can't get carbon dioxide

out it's just as big of
a problem as not getting

oxygen because half of our
exchange is not working.

There's the root of all
the problems in emphysema.

We have about 2.5 million of
these alveoli in our lungs.

Let's imagine that all
of them have lost their

elastin and they look like floppy bags.

What would emphysema actually look like?

If you have your regular lungs
that usually look like this,

which I hope that your lungs
don't look like this but

I'm sorry, I can't draw
any better right now.

That's what they usually look like,

and if they're filled all
the way up and air can't

get out it reminds me of big pillow cases.

Day in and day out they're

over-inflated and they can't go back down.

As this person has emphysema
for a long, long time

- remember it's chronic -
the ribcage and the tissue

out of the chest actually
changes shape because

the lungs are pushing on it all the time.

I don't know if you can
tell what I'm drawing at

all here but what I'm
trying to draw is a barrel.

People who have COPD are
often described as having

a barrel chest, which
means they're almost as far

from front to back as they
are from left to right.

With this shape changing
this person is very

uncomfortable to have to
carry around such a huge,

round chest and have air
not being able to get out.

I need to give him some hair.

I feel like that's the only way my

stick people can look like real people.

He's unhappy because his chest is like

a barrel sitting there,
he can't deflate it.

There's a special way that people with

emphysema often breath
that have earned them

the infamous nickname
of being a pink puffer.

There are two things that this
name is trying to describe.

Pink is because they don't lack oxygen,

so pink instead of blue.

Remember I said that the
oxygen getting into the lungs

is not a problem, our
problem is in exhaling.

They're pink because they don't

really lack oxygen in their blood.

Puffers describes the fact
that they have pursed lips.

Pursed lips, kind of like if
you imagine putting your mouth

around a straw, and they breathe
through this smaller opening.

The reason for this goes back
to this mechanical obstruction

we talked about earlier
with the door slamming shut.

Let's draw the door again. It's like this.

Usually when we breathe
out it's like the door is

hinged on something,
it's not going to close.

The air rushing out, it's pretty fast,

there's a lot of air because
the walls are pushing it out.

Imagine this is the amount
of air that goes through.

In emphysema with the door
unhinged and just flopping around

in the wind it is less likely
to snap closed like that

if there's less air going
through and it's going slower.

That's why people have figured
out that when you have COPD

if you purse your lips and you
breath slower it keeps this

airway open for just a little
longer, and every second

you can keep that door open
is a tiny bit more air out.

Let's just put that down in writing here.

We have the pursed lips,
that's the first thing.

Now we have this slowing down
of the speed of the air going

through, because the pursed
lips are trying to control it.

But the rate of their
breathing actually goes up,

just because since they're
breathing not so efficiently

they compensate by breathing
more times per minute.

This also contributes to
the fact that they look

like they're puffing and
huffing to other people.

In a nutshell if I were
to describe what I think

of emphysema as being in
my head it would be these

dilated lungs, a big barrel
chest, and this person

breathing with pursed
lips and they're puffing.