Integrative Biology 131: General Human Anatomy. Fall 2005. Professor Marian Diamond. The functional anatomy of the human body as revealed by gross and …

MARIAN DIAMOND: We continue
on down our respiratory tract.
We showed the nasal
epithelium, and today we're
down into the pharynx.

The pharynx, then, is
a fibromuscular tube.
A fibromuscular tube.

Muscular tube.
And it's going to extend
from the base of the skull,
from base of skull to the level
of the sixth cervical vertebra,
down to C6.

C for cervical.

So let's say its
relationships now.

So we'll the base
of the skull here.
We'll have the floor of
the nasal cavity here.

And we'll put in our
larynx down here.

So this is the base of skull.

And that would make
this our nasal cavity.

And this would be
our oral cavity.

And this would be our
larynx down in the neck.
So with this, then we can begin
with our pharynx coming down
this posterior wall.

And this area that's behind or
posterior to the nasal cavity,
logically it would be called
then the nasal pharynx.

So let's put in nasal
pharynx here in yellow.

So it's obviously posterior
to the nasal cavity.

Now what do you know about the
nasal pharynx that we've had
previously?
What tube do we find
originates there?

The Eustachian tube.

originates.

And where is the
Eustachian tube going?
To the middle ear, correct.
Goes to the middle ear.

why do we need a tube going
from the nasal pharynx
into our middle ear?
To equalize the pressure on
each side of the ear drum,
your so-called
tympanic membrane.
It equalizes air pressure
on tympanic membrane.

That's the official
name for the ear drum.
You know that when
you're in a plane
and you want your ears
to pop, so to speak.
You yawn.
How do you get
that air in there?
It comes up through your
mouth, your oral pharynx,
into your nasal pharynx
your Eustachian tube,
and into your middle ear.

So what kind of
epithelium are we
going to have in
our nasal pharynx?
You're building a nasal
pharynx, what kind of epithelium
do you want to put there?

Simple squamous?
No.
STUDENT: [INAUDIBLE]
MARIAN DIAMOND: Pardon?
That's right.
You're right.
You're starting right.
Pseudostratified columnar
ciliated epithelial cells
with goblet cells.
So for the moment we'll call
it respiratory epithelium.
With respiratory
epithelium here.

But I want you to say it.
So it's going to
be pseudostratified
columnar ciliated epithelium
with goblet cells.

What lymphatic tissue do
we have in the nasopharynx?
Tonsil.
What's it called?
What part of the body are we in?

So what kind of tonsil
are we going to call it?
Pharyngeal tonsil.
So you've got the
[pharyngeal tonsil here.

All right, that'll bring us down
next to our oral pharynx, which
will be posterior
to the oral cavity.
This is purely
diagrammatic here.

So our oral pharynx–

we'll put it in green–
is posterior to the oral cavity.

What kind of masses
of lymphatic tissue
are we going to have here?
STUDENT: [INAUDIBLE
MARIAN DIAMOND:
Tonsils, right, but what
are we going to call them?
It's a good guess, but it's not
right that's OK, you're trying.
I like it when you try.
OK we're going to
have the palatine,
because remember palatine
was going to be here.
And what's at the
base of that tongue?
The lingual, right.
You didn't say it.
You know what.
Can you tell I'm looking
at I'm looking at you?
No, I'm Looking at her
and she's not smiling.
All right, palatine,
the lingual tonsils.

So what kind of
epithelium are you
going to have when you get
posterior to the mouth?
STUDENT: Respiratory?
MARIAN DIAMOND: Do you
want respiratory there?
You're putting in all those
hamburgers and all that potato
chip and everything in that
delicate little respiratory
epithelium.
STUDENT: Stratified.
MARIAN DIAMOND: Stratified what?
Squamous.
So you want stratified–
good thinking–
stratified squamous epithelium.
No, it's true.
You have air there,
but you don't want–
the air can go by a little
bit of stratified squamous
epithelium, but you don't want
your delicate cilia and all
of those goblet cells.
So that's our oral pharynx.
Now the next division
of the pharynx
will be the laryngopharynx.

And since our
larynx is down here,
we'll do our laryngopharynx will
be the continuation of the two
down here.

So as we can see, it's
posterior to the larynx.

So you can see how you're
following that one wall will
be solid, but the rest
is open, because we
have to have air
then that's going
to go down in this direction.
But what kind of epithelium do
we want then in laryngopharynx?
What is going down
the laryngopharynx?

We're posterior to the larynx.
So what kind of epithelium?

You have food going down, right?
Stratified what?
STUDENT: Stratified.
MARIAN DIAMOND: There are
all kinds of stratified.
You've got to be correct.
Stratified squamous you
want something that's tough
like you have on your skin.
That's stratified squamous.
It's being abrased all day long.
You don't want any
cilia out there, right?
So you want stratified squamous.

By the time we finish, you'll
be able to answer all these,
because you'll understand why
the body's built the way it is.

Not that complex,
just need thinking.
Yes?
STUDENT: [INAUDIBLE]
MARIAN DIAMOND: Any
barriers these divisions?
No, it's just a continuous tube.
It just gets different
names because it
has different functions.
Sometimes it's pure
air there, sometimes
it's food and air, sometimes
it's just food, right?
There's a reason for everything.
So let's be sure we've
covered that well for you.

Let's continue then
with our larynx.
Move over for a division
of our respiratory system
in the pharynx here.

Larynx, It's again about
four to five inches long.

It will be surrounded
by cartilage.

It will be in the anterior–
this is anterior–

neck.

The cartilages Are obviously
there to keep the lumen open.

We don't ever want the
air passages to close,
so there are actually
nine cartilages.
The larynx is complex.

There are three paired
and three unpaired.

We're only going to take
the unpaired for examples,
just because of time, so you
have a general idea of why
you need them.

So unpaired currently.

First we'll have the
thyroid cartilage.

It's the largest.

It's the first
part of the larynx.
What does thyroid mean?
Any idea at all?
Shield.
Thyroid equals shield.

So it's going to look like
a shield to some people.

This is our thyroid cartilage.

And most people are aware of.
It's common name.
What's it's common name?
Adam's apple.

And you can feel it
right protruding.
Now in puberty in males
it increases its size.

Increases size at
puberty in males.

Because, as we'll
see in a minute,
the voice is
developed behind it,
and so the voice will
deepen at puberty.
Why is it important for
the voice to deepen?
So the male sounds
more threatening.
Well, you know the young male
voice is a beautiful soprano.
Not going to scare anybody.
So becomes more threatening.

We'll just put voice.

All right, so that's
our thyroid cartilage.
We'll take two more and
then come back to the voice.
The next one will be
the cricoid cartilage.
Cricoid.

And it will be just
immediately inferior
to the thyroid cartilage.

It looks like a straight piece
of cartilage from anterior end
because this an anterior view.

But if we look at
a lateral view,
well see it has quite
a different shape.

So if this is anterior,
this is what we would see,
but posterior it expands.
So this is a this is posterior.
Have you ever taken a ring
that you have on your finger,
do any of you wear rings,
and look at it sideways.
It looks thin here and
then expands back here.
They say it looks
like a signet ring–
that's what you see in the
literature– for its shape.
A signet ring shape.

And the other unpaired
cartilage for the larynx
is the epiglottis.
What do you know about the
epiglottis immediately?

What kind of cartilage is it?
Elastic, if you learn one thing.
So all the other cartilages
are hyaline, right?
The only one here is
elastic is the epiglottis.

So you know what epi means.
What does epi mean?
Upon.
What is glottis?
I'll show you what glottis is,
and then we'll come back to it.
We're going to look
at a longitudinal view
of the larynx.

Tube with these cartilages.
We'll see a fold of mucous
membrane in the wall.

Fold of mucous membrane.

And the superior one is
called a false vocal cord.
False vocal cord or fold–
using the term fold
more frequently now.
So this first one is
a false vocal fold.
Can anybody make it vibrate?
Does anybody have a cat?
A cat?
Kitty cat?
Nobody has cats anymore?
A couple of you.
Does your cat purr?
Yes, do you know how it purrs?
By vibrating this
false vocal cord.
Can anybody here purr?
You ever tried it?
No.
Just sits there.
So this vibrates
with cats' purr.
Aren't you ever curious
how it makes its sound?
Now inferior to the false vocal
cord is the true vocal cord
or fold.

And we're going to take
a superior look at it.

Stand up behind the tongue
and look down the larynx.

Superior view down the larynx.

And we'll see these two folds.

These are true vocal folds.

And laterally,
we'll have muscle,
the so-called
thyroaretinoid muscle.
The retinoid after
one of the cartilages
we're not going to study.
So this is our
thyroaretinoid muscle.

And the area between the vocal
folds is called the glottis.
So our Xs represent glottis
area between the folds.

So when the thyroaretinoid
muscle contracts,
it applies tension to the folds.
So contraction here,
tension on folds, and will
raise the pitch of the voice.

Don't you think
it's amazing when
you hear your beautiful singers
that you listen to all the time
to think what is causing
the wonderful sound?
If somebody wants to know
what a vocal chord looks like,
you just take your hands and
put those two folds together,
and all you have
to do is contract.
See them change?
For all those beautiful sounds.
But of course it resonates in
your sinuses and other areas
of quality bone you
have and so forth,
but to get those beautiful
sounds, can you make it?
No, you're too close.
You have to leave
air in the glottis.
See the glottis is
right there between.
You've got a huge glottis.
There you go, that's better.
All right.
But at least it
tells you now why
it's called an
epiglottis, because you'll
have this piece of
elastic cartilage
up here, so when you–
let me take off some
of the writing here.

if I have my tongue up here,
at the base of my tongue here
I'm going to have
this cartilage.

And that will be my epiglottis.

So every time you swallow,
your tongue goes back,
your epiglottis goes down.
So the food that you've just
put down your oral pharynx
goes into your
esophagus back here.
So you have that
protective device
so you don't get the food
coming down in your larynx.

So let's move on
then with these two.
What do we call
inflammation of the larynx?

Laryngitis.
Everybody knows that one.

That's inflammation.
You know your itis.
Inflammation of the larynx.

So we move on from the larynx.
What's the next part of
our respiratory system?
Where are we going to take
the air after we've left
the pharynx and the larynx?
STUDENT: [INAUDIBLE]
MARIAN DIAMOND: Trachea, sure.
It's all on the board, right?

So our next one is trachea.

It's about four to
five inches long too.

And it will connect, then,
the larynx with what?

With the bronchi,
our next division.
Got to prepare this
air to get it down
to where it can be effective.
So the trachea then consists
of a tube supported by about 16
to 20 C-shaped cartilages.

What kind of cartilage?

You know it's not
fibro cartilage
and you know it's not
elastic cartilage,
so what's your third cartilage?
STUDENT: Hyaline.
MARIAN DIAMOND: Hyaline, good.
So now we're going to have
our trachea coming down,
and it will have these rings
of cartilage as we see it.
This is an anterior view.

I'm not going to put in all 16,
just representative samples.
STUDENT: [INAUDIBLE]
MARIAN DIAMOND: Pardon?
STUDENT: [INAUDIBLE]
MARIAN DIAMOND: Obviously.
You get a person with
a neck long, right?

So let's take a cross section.
Through one of these.

Cross section of trachea.

And we're going to have
a lumen, of course,
because we've got to
keep the air going down.
So this is my lumen.

And then I'll have this
C-shaped cartilage.

This is anterior.
This is posterior.

I'll have an opening
of my C posteriorly,
so it's going to
keep this lumen open.

Well, you say, why,
if it's just keeping
the lumen open doesn't it circle
it completely and keep it open?

So this is my hyaline
cartilage in yellow.

In between the two ends
of the C is smooth muscle.

Smooth muscle.

Now what structure
is immediately
posterior to the
trachea in your neck?
The esophagus, good for you.
So a cross section
of the esophagus
here, it has a loose
lumen to expand depending
on what you're eating.
This is lumen of the esophagus.

so what happens when
you're talking to somebody
and you take a big
bite of an apple
and don't chew it too well,
and it goes down here esophagus
and it's expanding?
If you had a solid
wall of cartilage here,
there would be no room
for this esophagus
to expand adjacent
to the trachea.
so this is a safety
factor, having this open so
when this gets too big down
here and it stretches way over,
this can move in because
it's only smooth muscle.
If it were cartilage,
you'd have obstruction.
So it serves that
purpose, and it
has other purposes that we
don't have time for now,
but it is an interesting
arrangement here.
So the trachea has its
rings, but they're actually
C-shaped, not complete.
And we go from the trachea
then down to the bronchi,
bronchioles, and alveoli.
So next we go to bronchi,
bronchioles, and alveoli.

So we have our
trachea coming down.
It's going to branch.

I'm being very careful
when I start my branches,
accentuating them
in direction here.
This will be my right bronchus.
It's called primary bronchus.
And my left primary bronchus.

This, of course,
with my trachea.

So I'm bringing the air down.
Why it's designed this
way, I don't know,
but you see the right is
larger and it's straighter.
So if something gets
down in the trachea,
it can cause obstruction
in the right bronchus.
Because it's larger
and straighter,
it can be obstructed
more easily.

So we go from our
primary bronchus
to our secondary bronchi.

And then we go to
our bronchioles.
I'm just going to
draw them this way.

Bronchioles down to our
terminal bronchiole.
why do I accentuate
terminal bronchiole?
Terminal bronchiole.

Because at the
terminal bronchiole,
you all there is no
longer any cartilage.
You've got support
all the way down
to the terminal bronchiole.
How many of you have asthma?
Did you know it was at your
terminal bronchiole that
constricts and
causes you difficulty
with breathing because
there's no cartilage there?
That's a fact.
So asthma attacks here.

No cartilage, so
you get constriction
of your air passageway here.
Lumen with asthma.

Constriction of lumen.

So what do you do about it?
You take epinephrine,
make it = so you
can breathe for relaxation.
See why you have to know
your histology as well
as your gross anatomy?
Now as we leave that
terminal bronchiole,
we come to the
respiratory bronchiole,
and it differs entirely.

Respiratory bronchiole tells
you what's going to happen here.

The respiratory bronchiole is
the structural and functional
unit of the lung.
Structural and functional
unit of the lung.

What's the structural
and functional unit
of compact bone?
Aversion system.
What's a structural
and functional unit
of skeletal muscle?

Sarcomere, good.
Always review, review.
So now what have we got here.
We've got our respiratory
bronchiole coming down.
We're going to take
cross section of it.
Respiratory bronchiole, and
it's going to branch off
into alveolar ducts.

Did you ever think
of every molecule
of air you take in has got to
go through all these passageways
to get down and be functional?
These are alveolar ducts.

Alveolar ducts
lined with alveoli.
Each one of these little
pouches here is an alveolus.

So we're down to where the
exchange of gases takes place.
So CO2 and O2 exchange alveoli.

So how are you going to
build efficient alveoli
to allow this to take place?

What kind of epithelium
are you going to use?
Stratified squamous?
No.

What kind?
Simple squamous.
So our alveoli one have
simple squamous epithelium.

But we also have
secretory cells,
which secrete a lipoprotein.
Secretory cells
secrete lipoprotein.
And what do we call
that lipoprotein?
Surfactant.
Surfactant.

Surfactant.

Why do you need surfactant?
You have all these
little alveoli.
Do you know how many
you have in your lungs?
They say about 300 million.

So if they stretch them side
by side, how big of an area
would they cover?
Somebody has calculated
as big as a tennis court.
So a tennis court
is about the middle
of this auditorium for just
your alveoli stretched out.
What a surface to offer
for gaseous exchange.
So we'll just put size
of a tennis court.
So if your friends
ask you, how big
are your lungs, well,
if you stretch them out,
the size of a tennis court.

Think about it.
So
We've got surfactant.
But we don't want these little
thin layers to stick together.
So surfactant prevents
the alveoli from sticking.

Prevent alveoli from sticking.

So what else do we have
here for protection?
If you were building alveoli
that are sampling the air,
what do you want to do?
What's coming in that
air that you don't want?

So we're going to
add macrophages.

These big eaters in the
lung are called dust cells.
All this chalk dust is
being picked up in my lungs
by macrophages, dust cells.
That's why I use
colored chalk, so I can
have multi-colored macrophages.
Might as well think of a
good something that happens
with it because they're there.
But if you smoke cigarettes,
thank you, smoke cigarettes,
you're getting all that carbon.

Your cilia I haven't
been careful enough
in cleaning it out, they're
beating all the time up
toward your pharynx,
trying to get rid of it.
You get carbon down, the
dust cells pick it up.
Have you see in a smoker's lung?
Usually you get that
in about sixth grade
now just to get the picture.
It's black from the
carbon particles.
I could tell you
stories on that.
So it becomes black.
But now you know because the
dust cells that picked up
those carbon particles.
What else do we find down
here at our one last point
before we stop here?
The alveoli have elastic fibers.
Now you can reason,
sure, every time you
inhale you want those to
expand, let out, they recoil.
So we have elastic fibers
here for expansion and recoil.

Again, what's going to
reduce the elasticity
in those elastic fibers?
Smoking.
What's the disease caused
by when the person can
inhale but not exhale?
They have a barrel chest.
Emphysema.
Emphysema.
You've heard of emphysema.
It's no elasticity.
You take it out
with your hot smoke.

Emphysema.
Is your disease.
All right, let's review
with our slides then.

Thank you.
We can just begin.

All right, here we are
with our thoracic cavity.

Next time we'll look
at the gross anatomy
of the lungs, the right
lung, which has three lobes,
the left lung will
have two lobes,
and it will have a cardiac
notch for the heart.
The apex is up here
above the clavicle.
It will extend just a little
bit beyond the clavicle,
and the base is right
on your diaphragm.
In the next one, here
is our bronchial tree.
You can see the right bronchus
is larger, more straight,
so anything coming
in will lodge down.
It's typical on a medical school
test to ask which is larger.
This one goes off a little bit
at an angle and it's thinner.
We'll go to bronchi, secondary
bronchi, bronchioles,
terminal bronchioles.
Next one, what
kind of epithelium?

You could say
respiratory, but then I
think you've got
to know that it's
pseudostratified columnar
ciliated epithelium
with goblet cells.
And these are goblet cells.
They're so full of mucus
that that nucleus gets pushed
to the bottom of the
cell, so you can always
tell your goblet cells from
your columnar epithelial cells.
In the next one, what
kind of epithelium?
STUDENT: [INAUDIBLE].
MARIAN DIAMOND: Good for you.
Stratified squamous.
See how different it is?
It's thick and heavy
and protective.
It can be abrasive and not tear
it off and rub off any cilia.
So the body is just
beautiful the way
it's designed,
changing epithelium
depending on what's there.
In the next one, this
is down a bronchus where
you're going to have cartilage.
You'll have the pseudostratified
columnar ciliated
epithelium that's smaller.
We have some smooth muscle.
But here we have
cartilage, so you
know you're not down at
a terminal bronchiole.
So when you're
taking your lab exam,
you see this you know you're
above that terminal bronchiole.
In the next one, now
we're down at the alveoli.
We'll talk about its
layers next time.
These are all alveolus.
Lots of air space for it to
come in contact with the cells.
And then the capillaries will be
in here to take away the oxygen
and give back the
CO2 to get rid of it.
In the next one,
this is another one.
It said that it was going
to show me a dust cell,
but it's not very–
maybe this one.
This could be one.
Not obviously a
smoker's dust cell.
Next one, this just shows
an artist's rendition
of putting elastic fibers
around all of the alveoli
so that they can recoil.
But you can see what
happens when you
don't have the elastic fibers.
I think that's it.

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