MARIAN DIAMOND: All
right, let's continue then
with blood vessels today.
The science of blood
vessels is called what?
Angiology.
Angeology-- so "angio"
will be vessels.
So we're going to look
at the blood vessels
in the systemic circulation,
which will start--
this will be systemic
circulation going--
if we have the heart
and our four chambers,
our left ventricle,
our right atrium--
and will follow arteries.
The ascending aorta
is coming out here.
But we're just got to call
it an artery for the moment,
coming from our left ventricle.
This will be an artery.
And then gradually,
it will decrease.
Oops.
Gradually-- just one second.
I'll get rewired.
It will gradually decrease
in size to form arterioles--
arterioles, these are smaller--
and then continue to decrease
in size down to capillaries.
These are capillaries.
And then we come back
up on the venous side
in small veins called venules.
Venules-- and these will
enlarge to form veins and bring
the blood back into
our right atrium,
giving us a circulatory
system here.
And this will be our veins.
Now, all of these vessels have
three layers, except what?
Capillaries.
Capillaries will just have two.
They'll have endothelium
plus abasement membrane.
Some authors like to
use the term "lamina."
Abasement, abasal
lamina-- same thing.
So now what we'd like to
do is begin with arteries.
And there are two major classes
of arteries, elastic arteries
and muscular arteries.
And we'll begin with
the elastic arteries
because they're the ones
coming out from the heart,
so that they're going
to be expanding.
They need elastic tissue.
Can I take this off?
We call the coats or the layers
of arteries tunics, tunics.
So we'll have the
layers ill-defined here.
Just those are tunics.
The opening is called what?
A lumen, yes, a lumen, to
give it its specific name.
So what we'd like to start
with will be the tunics
on the elastic arteries.
We said we had three
of these layers.
So these are our
elastic arteries.
We're going to start
with the first one, which
is the tunica intima.
So this is inside
next to the lumen.
Well, we'll have
endothelial cells,
because throughout your
whole vascular system
you're lined with endothelial
cells, endothelial cells
plus connective tissue fibers.
And these will be
primarily elastic.
Then we'll have the tunica
media, the middle layer,
tunica media, which will have
predominantly elastic fibers,
plus a little smooth muscle.
A little bit, we'll
put, of smooth muscle.
Now, our third
layer, again, it's
a tunic, the tunica
adventitia, adventitia.
And again, for these elastic
arteries, lots of the CT
will be elastic fibers,
but also collagenous
fibers, collagenous
fibers for strength.
The adventitia has something
else that the other layers
do not have.
It has the blood vessels
of the blood vessels.
So we'll find the blood
vessels of blood vessels
in the adventitia layer.
The correct name for this is
vasa vasorum, vasa vasorum.
Saw It's funny how
you remember things.
I remember when I first learned
that when I was your age.
Vasa vasorum, just saying
it now, it's all up there.
So this gives us then the
wall of our elastic artery.
Now, where do we find
elastic arteries?
We'll show them
coming from the heart.
So this will be--
what are we calling them?
What do we call the names?
I say examples of
elastic arteries.
So one is going to be
our ascending aorta.
We know that it's coming
from the left ventricle.
So we're going to
put in one coming up
equals the ascending aorta.
Does anybody know what
the first branch off
of the ascending aorta will be?
What's the most important thing?
STUDENT: [INAUDIBLE]
STUDENT: Coronary artery.
MARIAN DIAMOND: Coronary artery.
I always tell it's a
good philosophical point.
Take care of yourself so you
can take care of everybody else.
The heart takes care
of itself first.
The first branches off
of the ascending aorta
will be the right
and left coronaries.
We're just going to
put them in here.
So this will be number two,
right and left coronaries.
And then number three--
as we come up, they're to
go off in this direction.
This will be the
brachiocephalic.
Brachio-- what's "brachio" mean?
Arm.
"Cephalic?"
Head.
So we'll send branches down
the arm and also to the head.
And also, the term
that used to be used--
but when we have our vascular
surgeon come, he uses it still.
So I'm going to give
it to you, so you
know that the synonymous
artery of the brachiocephalic
is also the innominate.
Innominate artery is the same.
And now our next
one will be the arch
of the aorta going off in
the opposite direction here,
a big arch.
It's about an inch in
diameter, unless you
get an aneurysm here.
It gets to be five
inches or something.
Take good care of
your blood vessels.
Number four will be
the arch of aorta.
And then we'll come back and
put in the left subclavian.
This will be five.
Left subclavian,
what does that mean?
Under the clavicle, just
palpate your clavicle.
You know you've got a subclavian
under there, a big vessel.
And off of the subclavian
in this direction
we're going to have the right
common carotid, number six.
Oops, I put left.
I'm sorry.
That should have been
right subclavian.
I apologize.
This is definitely right.
I apologize.
Then six is the
right common carotid.
And then we can follow
over to the opposite side
where we'll have seven, which
will be left common carotid.
Left common carotid--
and eight is what then?
same as on the
opposite side-- what
did we have over on
the opposite side?
STUDENT: Subclavian.
MARIAN DIAMOND: Subclavian,
sure, left subclavian.
So these then are
your elastic arteries.
So when you have systole
down here in the ventricles,
that pump is going to
expand these arteries.
And then when they
recoil, they keep
the blood propelled, to keep
it going around the body.
So that's why you
need elasticity.
And we'll see what happens
when you lose it with aging,
which is a possibility.
All right, let's take then
a few of these as examples
and expand upon them.
Let's take the
coronary arteries.
Can I take this off?
No objection.
Thank you.
So coronary arteries, why
do we take these arteries?
Because a third of the
population that dies in the US
will die of heart
attacks, blockage
of your coronary arteries,
or what are commonly
called heart attacks.
So a third of the
population that die,
a third of deaths in the US in
a year are due to heart attacks.
So it does sound-- this is
important that you understand
the mechanism, what happens.
What are we going to do first?
We're going to be obstructing
that tunica intima.
The first stage in getting
plaques in arteries
begin in tunica intima.
What do we call when we
start getting plaques
in our arteries?
What's the term?
STUDENT: Atherosclerosis.
MARIAN DIAMOND: Atherosclerosis
are plaques in arteries.
And these plaques can
be rich in cholesterol.
That's why you watch your diet.
In fact, it's been reported
that some $25 billion
are spent in a year on
anti-cholesterol drugs,
on anti-cholesterol drugs.
So it's very important
when you get your physicals
when you're young to
find out your cholesterol
level in the blood, so
you know what you're
treating, so you can watch it.
Because if it gets above 200,
then it becomes more dangerous.
Cholesterol-- it's
just the number used,
200 plus becomes dangerous.
STUDENT: [INAUDIBLE]
MARIAN DIAMOND: No.
So it's very easy to
get your blood tested
and to find this out and to
know how to change your diet.
If you're eating ice
cream every other day,
you know to switch to yogurt.
You just learn there are
substitutes for the heavy fats.
You can do it.
But look at how many
people do not, tremendous.
So now let's see where
we want to take this.
Say that you've got your
coronary obstructed.
How are you going to get
rid of the obstruction?
You have an obstructed coronary.
You'll have an operation
called angioplasty.
Most have heard of it today.
Angioplasty, that's the
operation to remove plaque.
Basically, there are two steps.
We can use some of the basic
anatomy that we've learned.
We're going to inject
a radio opaque material
into the femoral artery.
Where would you go
to the femoral artery
if you were going
to inject something?
STUDENT: [INAUDIBLE]
MARIAN DIAMOND:
What do you call it?
STUDENT: Femoral triangle.
MARIAN DIAMOND:
Femoral triangle, sure.
So you know where it is now.
So we're going to inject
a radio opaque substance
into femoral triangle.
And this will outline
your blood vessels
so they can be
seen with an x-ray.
So with an x-ray--
so with this technique,
you can localize
where is the obstruction
in the coronary artery.
Localize obstruction.
So now you know where it is.
So the second step will
be to insert a catheter
in the femoral artery.
Insert catheter.
A catheter is a tube.
And at the end of
the tube, there
will be a balloon, because
what one's going to do
is inflate the balloon to
push the plaque to the wall.
So insert a catheter
with a balloon.
And the balloon is in
what's called a stent.
With a balloon and a stent--
what is a stent?
In this case, the stent
is a wire mesh tube,
equals a wire mesh tube.
So here we are
with our catheter.
And it's got a balloon
attached to it here.
And surrounding the balloon
will be this stent, wire mesh.
And we're coming into
an artery with a plaque.
So this is a plaque.
This is my artery.
When they get there, then
they will inflate the balloon,
and it will extend this
stent up against the plaque.
Then we're going to insert
catheter way down here
in the groin, thread
it all the way up
through your abdominal aorta,
around through your arch,
and around to ascending aorta,
and into your coronary artery.
That's where we are here.
And here we'll
inflate the balloon,
enlarge stent to press
plaque against wall.
And then you can remove the
balloon and the catheter
and leave that stent in place.
There was a professor
in endocrinology.
I'll catch it in a second.
And he had an obliterated
or a blocked coronary.
But he got to watch the surgery.
And he could see
that no blood was
going into his coronary
that was blocked.
And as soon as they put it in
the stent and he saw the blood,
he said that was one of the
greatest thrills in his life,
to know that his heart was once
again going to be refurnished.
He came back.
And I was in lab.
And he came in and disturbed
to tell me the excitement.
So let's hope that you keep
healthy arteries so you
don't have to do that.
Yes?
STUDENT: When you
insert a catheter,
doesn't that
restrict blood flow?
MARIAN DIAMOND: To a
degree, yes, but not wholly.
It's not going to be that
big, not until you get up here
and get it and
then get this out.
All right, that's very clever.
What are they doing today?
This is very common.
But they're using a laser
to vaporize the plaque.
They have a catheter
with a laser.
And they thread the
catheter up to the plaque
and then activate the laser.
And it disintegrates the plaque.
It "vaporizes" is the term
they use, vaporizes plaque.
So what next with technology?
That's why you take
these basic courses,
to see how you're going
to improve things.
Yes?
STUDENT: So does the
stent stay up afterwards?
MARIAN DIAMOND: Yes, the
stent stays in there, right.
All right, so that
tells us if you
get a plaque in your
coronary artery.
What happens if you get plaques
in your common carotids?
I think we'll come back to that.
Let's see which one
we want to take now.
No, I can take common carotids.
So it's quite common
to get plaques
in your common carotids.
So we have our common
carotids coming up.
Here we had our heart.
We have our ascending
coming over to our loop,
and our common
carotid on the left,
our brachiocephalic out
here, and our common carotid
on the right.
And they'll stay
as common carotids
till they get up to the
superior boundary of what?
What is this in
here, this cartilage?
STUDENT: Thyroid?
MARIAN DIAMOND: No,
thyroid's not cartilage.
STUDENT: [INAUDIBLE].
MARIAN DIAMOND: It's the larynx.
We'll study the larynx.
It's part of your
respiratory system.
And it has to keep
cartilage to keep it open,
so it doesn't collapse.
But at the superior
border of larynx,
the common carotids bifurcate.
Common carotids
bifurcate, bifurcate
into an internal carotid
and an external carotid.
This is my internal carotid
and my external carotid.
At that point a
bifurcation, that
is a common site for plaques to
form, because you're coming up
and you hit the top
here before it goes off.
So plaques commonly form at
bifurcations in the carotid.
This area is important because
we have two sensors here.
We have a carotid body.
Again, this is at the
bifurcation of common carotid.
We have the carotid body that
regulates blood pressure,
regulates--
this is in the wall
of the artery--
regulates blood pressure
via the ninth cranial nerve.
We also have a very important
structure, the carotid sinus.
What does the carotid sinus do?
It regulates respiration by
sampling oxygen in the blood,
regulates respiration
by sampling oxygen.
So you can see how important.
Feel in your neck.
Feel your larynx.
It's your Adam's
apple, common term.
So you know just
to the right there
will be this bifurcation
of your common carotid,
and that you have these very
important sensory mechanisms
right there in your neck as far
as your blood function goes.
So let's look then
at what happens
if you've got your plaques
in the common carotid,
as we go down, get
plaques forming here.
How are you going to determine
whether there are plaques
there?
Fortunately you
don't have to come up
through the femoral artery
clear into the neck.
What can they use to
determine plaques in the neck?
Ultrasound.
With ultrasound, you can
determine plaques in the--
ultrasound to determine the
plaques in common carotid.
And they are quite common,
these plaques in this area.
So older people get ultrasounds
to see if they have plaques.
What do they do if
there are plaques?
They do a procedure
called endarterectomy,
me endarterectomy.
Endarterectomy,
that's a procedure
to remove plaques
in common carotid.
And I was just reading
yesterday that they
are saying that on
many people over 80,
it's still safe to
do an endarterectomy.
And it certainly increases
the blood supply to the brain.
There's the typical story they
tell about the executive who
was losing his memory,
and his secretary
kept trying to make up for it.
But finally, she talked him into
getting it an endarterectomy.
And they went in and
cleared out the plaques.
And he could get the blood
again going to his brain.
Then his memory
came back very well.
So there are lots of reasons
for decreasing memory
when you get older.
You've got to consider the
health of your vascular system.
So these then give
you some examples
of our elastic arteries
and what they do
and how we can
keep them healthy.
Let's look at our
muscular arteries
then, because obviously the
majority of your arteries
are muscular arteries.
I've only given you
eight elastic arteries.
So we have muscular arteries.
Have you ever thought
about your arteries before?
Not too often?
They're down on
the list, are they,
when they're so important?
These are also
called distributing.
So how are you going
to tell the difference
between a muscular artery
and a redistributing artery?
By its coat.
You have a tunica intima.
Let me get more room.
Tunica intima, sure it's going
to have its endothelial cells
and some connective tissue.
But it also has an
internal elastic membrane.
Internal-- when I
show you pictures,
you'll see how distinct it
is, internal elastic membrane.
If a third of us are going
to die of vascular problems,
I think we should really
be well aware of what
our blood vessels are.
We've got a tunica media.
Who was the professor
in anthropology
a few months ago died
in front of his class,
had his heart attack?
It can happen.
Tunica media-- you're all
going to look at me funny now.
When are you going to die?
OK, tunica media-- since
these are muscular arteries,
we're going to find
the whole media filled
with smooth muscle,
smooth muscle.
And then the tunica adventitia
will be connective tissue,
collagenous fibers.
These are predominant.
But you can begin to
figure out, if you
want to get a tough protective
coating around an artery,
you're going to put
in collagenous fibers.
This will protect the
artery and give it strength.
So it definitely
will then have--
in addition, we had an
internal elastic membrane.
Our adventitia is going to have
an external elastic membrane.
So we'll see pictures.
So these are the
three constituents
that we have in the walls
of our muscular artery.
Now a few examples then
of muscular arteries--
let me take the
internal carotid.
You saw where it divided.
It's going to feed
75% of your brain.
This whole brain is getting
fed by the internal carotid,
supplies 75% of the
blood to the brain.
So you see how important.
You can see why they're
called carotids,
which what did carotid mean?
Stupor, right?
Press on them, look
at how much blood
you stop going to your
brain, terribly important.
First branch of the
internal carotid
will be the ophthalmic artery.
Where is it going to be going?
To the eyeball,
ophthalmic artery,
very important for you to see.
Ophthalmic artery
goes to the eyeball.
Now, when you take
advanced anatomy,
you get all the arteries
coming off of internal carotid.
I'm giving you two, the first
and the terminal branches.
Terminal branches-- anybody
know the terminal branches?
They're to supply your cerebral
hemispheres, the anterior
cerebral and the middle
cerebral, anterior cerebral
and middle cerebral.
So we can show how much of
your cerebral hemispheres are
supplied-- thank you--
by these two arteries.
I'd like to finish if I could.
So if we look at a lateral
view of cerebral hemispheres--
I learned yesterday
that we're establishing
a new institute called
theoretical neurobiology.
And they'll be studying
only the cerebral cortex
and the thalamus leading to
it, fantastic big new thing.
So here's our lateral view.
Our medial cerebral artery
will be supplying an area
like this, all of this side.
Put your hand on the
side of your head.
You have your big hemispheres
beneath it in red.
We've got the middle
cerebral supply.
And we'll put anterior
cerebral in blue,
even though it's an artery,
just to distinguish it between.
So this is all
anterior cerebral.
And just one more thing here--
we'll pick up the
vertebral next time.
There's a very
important area here
on the inferior frontal lobe.
This is left side.
What is it?
STUDENT: Broca's area.
MARIAN DIAMOND:
Broca's area, right.
X equals Broca's area.
This is motor speech.
For me to be talking
to you now, mine
is firing, getting more
blood supply, motor speech.
Students will come in and say
their grandmother had a stroke.
And I say, tell me one symptom.
She can't talk.
You know immediately that
it was a middle cerebral.
And this is a
question you'll get
asked when you start on the
floor with your residence.
What vessel supplies
lateral cerebral cortex?
And I want my
students to say what?
Come on.
All this work and
they say nothing?
Middle cerebral,
don't forget it.
There's more students
come back years
that say well, thanks
for telling us,
because that was the very
question when they get
to the brain they ask,
because it's a large supply.
We'll learn when
we study the brain
how much more is supplied here.
Let's look at slides.
We have just a few minutes.
And we have some good slides.
So please let's move forward.
Slide first.
This is an elastic artery.
This is the lumen.
The endothelial cells
are here, very thin.
But all the way the
lines are elastic fibers.
You can't see that
there's one layer,
then the middle layer,
then the outer layer.
There are so many
elastic fibers.
In contrast to a
muscular artery--
next slide-- look at that.
You can distinguish.
Here is my internal
elastic membrane.
Here are my endothelial cells.
This then is my muscular layer.
This is all smooth muscle.
And this then is our adventitia.
Very clear differentiation
between connective tissue,
smooth muscle, internal
elastic membrane, endothelium.
And the lumen in this
case is filled with blood.
You wonder how they
got that tissue.
Why isn't it clear?
Why is there blood after death?
Who knows?
Next one-- now this is
a longitudinal section
of a muscular artery.
Because you're
going to see them.
When you get to
path, you have to be
able to see every different
slice to tell what it is.
You might say, well,
this is an abnormal.
No, it's not abnormal.
Your endothelial cells-- here's
the internal elastic membrane.
Here's your muscle,
cut in cross-section.
And here is your
connective tissue.
Next one-- this is an arteriole.
It's much smaller.
And these are circular smooth
muscle cells around it.
It will have its little
connective tissue,
its endothelium, but
greatly reduced in size
because it's feeding
into the capillaries.
Next one-- and this
shows then the arteries
we've been mentioning.
As we see the ascending, they've
put off some little coronaries
here and then show your
brachiocephalic here,
and then a common carotid.
We didn't get to the vertebral,
but we will next time,
because the vertebral will
be supplying 25% of the blood
to your brain.
But it's coming up
the back of your neck.
And so you follow the
common carotid up,
and the external
carotid is going
to go external and
supply your face
and scalp, while the
internal goes into the brain.
Next one-- and this
shows at the brain,
here is your middle
cerebral supply.
Here is your middle
cerebral artery,
this whole big circle here.
And if this were a left
brain, Broca's area
would be about in here.
This shows a medial slice.
We've cut through the brain.
Here's your corpus callosum.
Here is here anterior
cerebral artery.
When they first started
split brain preparations,
to cut the corpus
callosum, they kept
getting bleeding
because this anterior
cerebral hugs the
corpus callosum.
And I learned from some of the
lesser people down at Caltech,
when they cut, they
finally learned
not to go so far forward.
And they left a little
corpus callosum,
even though they called it
a split brain preparation.
They didn't want
to get this artery.
Next one-- and this is
what it looks like if we
take all the brain away.
And that's the arterial
supply of your brain.
Don't you appreciate it?
Now picture that
inside your skull.
Transpose it.
When we study the
brain in detail,
as we do in the
graduate class, then you
get all those arteries.
You see, I'm giving
you just a suggestion.
Don't you appreciate
your brains?
