00:00
Welcome to Pulmonology.
00:03
Our approach in this lecture series will be the patient
walked in through that door with signs and symptoms.
00:10
The patient walks in with cough. The history of that
cough, "Was it a dry cough?" "Was it productive?"
In terms of productive, what color was it? Was it stained as being brown?
Was it rusty? Was it yellow? Was it green?
Signs and symptoms is how you need to
approach pulmonology here so that you have a
broader view of what's going on with pathophysiology for
each of the diseases and infections that we shall cover.
00:38
We'll walk through restrictive and obstructive diseases, but prior
to any of that let's first take a look at signs and symptoms.
00:47
Overview of our bronchial tree. Begin at
the proximal region with the trachea.
00:55
And then as we divide, divide, divide into branches or divisions, by the time you get all the
way down to the alveoli distally, well you got to imagine as to how thin that alveoli is.
01:07
Right? And what about that trachea? The trachea is a
supportive structure. It is basically an air tube.
01:15
That's exactly what it is. Meaning to say that it is then going to take the air
that's coming in from the ambient air which has sea level is, what please.
01:25
Good, 760 mm as sea level. And you need to make
sure that that trachea is nice and strong.
01:33
So therefore it is made up of
cartilage or cartilaginous rings.
01:38
And then also, in the upper portion or the
proximal portion of our respiratory tree,
then we must have a method by which we
defend ourselves against that ambient air.
01:49
Think about ambient air. There's a lot of stuff in there,
it has antigens, it has allergens, so on and so forth.
01:56
So we need to make sure that we keep things like that out and so therefore
think about the histology here as we branch deeper down into the alveoli.
02:04
That's important for you to
understand and keep in mind.
02:07
I don't want you to just take a look at this and read what's
on the Y axis or on the vertical or parallel words here.
02:15
That's just giving you an overview and things that you already know but what
you're always bringing into play is "What is the function of the trachea?
What kind of cells does it have?" It has mucociliary clearance.
It has to be columnar cells. It has to be ciliated.
02:30
And the mucociliary clearance helps you take out any
unwanted particles that you're breathing in, hhhmmm.
02:38
And you have to have mucous. Right?
That's the proximal portion.
02:41
And then as you go further distally about the F
cilia down in the alveoli, of course you don’t.
02:47
Why is the alveoli so thin? Type 1, type 2 pneumocytes are present.
We know that it's squamous like, it has to be very thin.
02:57
Because what's across the alveoli
membrane please? Exactly.
03:01
It's the pulmonary capillaries responsible
for quite a bit of gas exchange.
03:05
So why would you want large columnar cells down there?
Now, what does that mean to you pathologically?
Now, what we shall do moving forward?
Please understand.
03:13
And so we're going to plug in our infections into this
respiratory tree. We're going to add in some diseases.
03:19
For example, we'll put in the most common
lung cancer, adenocarcinoma. Isn't it? It is.
03:26
Adenocarcinoma is
the most common.
03:27
But Dr. Raj, I thought that smoking was heavily, heavily
associated with small cell lung cancer. That it is.
03:35
Or squamous cell cancer.
That it is.
03:37
However, what if you're a non-smoker and could
you still develop lung cancer? Sure, you could.
03:44
In the United States, it
is the number 1 killer.
03:47
This is because lung cancer is the leading cause of mortality from cancer and the
6th leading cause of mortality overall according to the World Health Organization.
03:56
So therefore, we will have to know everything
about bronchogenic adenocarcinoma.
04:00
So as we go through here, our doing here is setting up a nice
little tree here and as we have in the proximal portion,
these are cartilaginous and as you move further down into the
bronchiole, the alveolar duct, and then in the alveoli. Hhhmmm.
04:16
The upper portion is known as a conducting zone.
That's an important description that you need to know.
04:22
Remember all these from anatomy
and physiology? Right?
And the conducting zone literally is conducting
air from the outside world down into the trachea.
04:30
And then as you move distally beyond the alveolar duct and
you get into the respiratory zone. Makes perfect sense.
04:37
What's the respiratory zone responsible for?
Gas exchange hence the name respiratory.