MARIAN DIAMOND: We go
to a new system today.
We have barely gone
through the skeletal system
to give you something
to work with,
and now we're going to
put the muscles on it.
Who knows what the
term muscle means?
Nobody?
It is Latin, musculus.
What does musculus sound like?
Little mouse.
Why are muscles
called little mouse?
If you had to guess,
what might you say?
Can I borrow you a minute?
I was hoping--
STUDENT: [INAUDIBLE]
MARIAN DIAMOND: --somebody was
going to have short sleeves on.
[LAUGH]
And I caught him right
here in the front row.
[LAUGHTER]
Now pull up your arm
and show your biceps.
[CHEERING]
[APPLAUSE]
See?
You think that little mouse
running up and down the arm?
Who knows, but thank you.
I didn't plant him.
He just happened to be there.
Thank you very much.
But at least you'll remember
what it means now, won't you?
[LAUGH]
All right.
Let's look at
functions of muscles.
First movement,
obvious, for skeleton.
Move skeleton.
But also to provide control of
such structures, such openings.
Let's just put
control of openings.
And we can give examples there
of the mouth and the anus.
They both have skeletal
muscle around them.
Then we need to
stabilize our joints.
Stabilize our joints
with our muscles.
What does that
allow you to do to?
Maintain your posture
as you're sitting there.
Otherwise, you'd just collapse.
So we want to maintain posture.
Then our muscles
can produce heat.
When you're cold, you
run around, right?
Get warm.
With exercise.
What else can
muscles do for you?
Just think of facial expression.
You take one look
at any one of you.
In two seconds,
you move a muscle,
and one can get an idea of
what you're thinking, right?
Facial expression.
See whether you're sad,
happy, fearful, and so forth.
But it is amazing
how rapidly you
can change facial expression
with just a thought
or seeing somebody.
You ever thought
about what's involved
every time as I look at your--
what are we doing?
STUDENT: [INAUDIBLE]
MARIAN DIAMOND:
Switch Microphones.
All right.
[TAPPING]
Sounds like it's working.
Is that better?
Or didn't you notice that
the other one wasn't working?
[LAUGHTER]
So we were mentioning
our functions here.
And protection.
In what way is it protecting?
Protecting your
eyes, for example.
Quickly close them if
something foreign is coming.
Close your mouth if
something foreign is coming.
So close eyes and mouth.
Anybody think of any other
functions for muscles?
You ever thought about your
muscles except when they hurt?
Well, what is nomenclature then?
How do we name muscles?
Well first we can name
them by their shape.
We can give the
example of the deltoid.
When we study the
deltoid, we'll see
that it has a base across here,
comes to an apex down here.
Looks like an upside
down Greek D. Deltoid.
We can tell them by
the number of heads.
We can have biceps, two heads.
Triceps, three heads.
Quadriceps, four heads.
Does anybody have a muscle
that has five heads?
You know of any creatures in
evolution that have five heads?
We can tell muscles
by the length.
They can be short, brevis.
Or long, longus.
So you can have a muscle in
your forearm, which is called--
this would be an example--
extensor carpus radialis longus.
So you've had all those words
now, so you can figure out
where it is, what bones
are involved, right?
Is it going to be medial
or lateral forearm?
Lateral, sure.
You've got radialis in there.
So you begin to put things
together rather than
just memorize.
That's what it is.
All right.
You can have location.
We can have biceps brachii.
Where are they going to be?
STUDENT: [INAUDIBLE]
MARIAN DIAMOND: Right.
The one we just showed.
Biceps brachii gives
you the location
of those biceps in the arm.
You can have biceps femoris.
Did you know you had
biceps in your thigh?
You do.
They'll be in the thigh.
Have you ever known that?
You ever thought about them?
No?
You can have intercostals.
Where are intercostals?
Where are they going to be?
Between the ribs, right?
Just very simple.
But their location,
the name designs it.
Between ribs.
Or a temporalis.
Where's it going to be?
STUDENT: [INAUDIBLE]
MARIAN DIAMOND: Over here.
Temporal bone.
Sure.
Just giving you ideas that
you can figure these out
by their location, their
names, integrate them.
Very simple once you've
got all your bones.
They can be localized
by attachments,
where they're attached.
What's a big one in your neck?
Sternocleidomastoid, so you know
exactly where it's going to be.
Sternocleidomastoid.
Goes from sternum, clavicle,
What does clavicle mean?
It's a little key to some
people, the clavicle.
I don't know what kind of
keys they used in those days,
but it's called a key.
And then to your mastoid
process and your temporal bone.
So you can figure
out immediately
what it's going to do.
You'll get its function once
you know where it's attached.
If that contracts,
what's going to do?
When one contracts,
one side of the head.
Both of them-- that's why
it's called a prayer muscle.
But we'll get that when
we go through later
and define their
functions for you.
Now we've had the
functions of our bones.
Well, obviously, the
functions of the muscles
are going to follow
along the same.
This is just a
brief introduction
before we get to
the specific ones.
So from functions
from our muscles
we'll have flexors, extensors.
What's the next one?
STUDENT: Adductors.
MARIAN DIAMOND:
Adductors, abductors.
Supinators.
Supinators, pronators.
All of these
different functions.
What are supinators
and pronators?
We're going to see
those with the hand.
As the radius rotates,
we turn the hand.
When the hand is palm
up, it's a supinator.
Palm down, pronator.
Supinator, palm up.
Pronator, palm down.
How do you remember that?
Silly little thing.
Bowl of soup, palm up, right?
You ever been on a camping trip
and had your soup in your hand?
Hmm.
You haven't really
lived, have you?
[LAUGHTER]
Lots more to think about.
All right.
We have what are called prime
functions and antagonists.
A prime mover and an antagonist.
The prime mover is
the main muscle that's
carrying out the function.
The antagonist has to relax so
the prime muscle or mover can
function.
So this relaxes.
So example you'll learn,
your biceps is helping flex,
but it can only flex
if the triceps relaxes.
So the biceps are
called prime movers.
These are just terms that
you see in the literature
so you'd be familiar
when you run across them.
So attachments to limbs.
We need our basic terminology
for attachments to limbs.
We have origins and insertions.
And yes, you learn those
because when you know them,
you can figure
out the functions.
So the origins in the limb
will be at the proximal portion
of the limb.
Proximal.
And the insertion then distal.
So you can figure them out.
So you have a brachioradialis.
Usually, the first
part is the origin,
so this will be distal humerus.
Brachial for the arm.
And distal radius here.
And you say, my.
They're both distal.
But this one is closer to
the trunk, the one that's
at the distal humerus.
And it's going down
to distal radius.
This is the origin,
this is the insertion.
The origin is usually
closer to the midline,
but it's difficult to
use the midline here,
so we'll use the superior
aspect of the limb.
When we get to
the chest muscles,
insertion will be
close to the midline,
and insertion will be distal.
All right?
Not complex.
It's just a matter of
getting basic terminology.
So with this now, let's start
with the muscles of the head.
And just take a few.
How many muscles do
you have in your body?
STUDENT: [INAUDIBLE]
MARIAN DIAMOND: If
we took them all,
how many would we have to take?
638.
Is that the correct number?
STUDENT: No.
MARIAN DIAMOND: What's
the correct number?
STUDENT: [INAUDIBLE]
MARIAN DIAMOND: As of
today's world, it's 639.
In 1996, they found a new
muscle in the human skull.
It's only an inch
and a half long.
It's posterior to the orbit and
it goes down to the mandible.
Nobody knows what it does.
[LAUGHTER]
But it shows that
anatomy is not dead.
They can still find
things that have never
been found or never looked for.
So 639.
OK.
And we're going to
do muscles of head,
and the first one
we're going to take
is the occipital frontalis.
And you know immediately
where it's going to be, right?
So if we take a skull and
we put in our occipital
and our frontalis, we
have something like this.
Now what's between the two?
There's a thin, tough
layer of connective tissue
that comes across, forming a
helmet over your skull here.
And this is called the
galea, which means helmet.
Aponeurot-- aponeurotica.
Galea.
Aponeurotica.
What in the world
is an aponeurosis?
You're going to see
these around muscles.
Thin, tough layers
of connective tissue.
So this is helmet galea.
It's a thin, tough or
strong, whatever word
you want, connective tissue
that connects the occipitalis
with the frontalis.
So for the occipital
component, the origin
is the occipital bone and
our little mastoid process.
And it's going to insert--
I'm just going to abbreviate it
into that galea aponeurotica,
as you can see here.
It's going to insert there.
It originated here.
Insert at the
galea aponeurotica.
Now comes the question,
what's its function?
Can anybody here contract
your occipitalis?
No, we had a student, and
he'd come up and show us.
Usually we have one.
Nobody can do it?
Can you even try to
even think about it?
Have you ever
known it was there?
He could, and this
whole back of his hair
would go up and down when he
was contract-- you doing it?
No, you're doing your
frontalis beautifully.
All of us can do frontalis.
That's fine.
But you've got one muscle there
that has just been going--
freeloading.
So we've got frontalis.
Origin will be the
galea aponeurosis,
as we have its origin here.
And its insertion will be in
muscles in the superior orbit.
We've got the orbit here.
So in superior orbit,
this will be insertion.
Just to keep it here,
I'll take it up high.
Will be the muscles
in superior orbit.
And partially, it will be the
orbicularis oculi example.
Orbicularis oculi.
So you can see
that this frontalis
has no bony attachment.
No bony attachment.
Now who can figure out
what its function is?
What's the function
of your frontalis?
Look at the person
sitting next to you.
Ask them to contract
their frontalis.
So action.
Raise your eyebrows and
wrinkle your forehead, right?
Very important to know.
You may not think so, but it is.
Raise eyebrows and
wrinkle forehead.
Now is there anybody
who can't do this?
Look at your neighbor.
Can he do it?
She?
Everybody can do it.
Then you have healthy
seventh nerves.
Your seventh cranial nerve
innervates this muscle.
So it's very
important clinically
that we begin to
learn the nerves that
are going to be coming to some
of our muscles to begin with.
So the seventh nerve innervates.
So when you come for a clinical
neurological examination,
the easiest thing
for them to say
is just wrinkle your forehead
and raise your eyebrows.
They know your seventh
nerve is working,
this motor component at least.
So let's go on now and take
some muscles in the orbit.
Let's take the levator.
This will be in orbit.
Levator palpebrae.
So you can tell right away.
What does it do?
STUDENT: [INAUDIBLE]
MARIAN DIAMOND:
What's palpebrae?
Eyelid.
What's it doing to the eyelid?
It's raising it, right?
So this raises eyelid.
Its origin will be
the superior aspect
of the orbit, superior orbit.
And it's going to insert
in the upper eyelid.
Origin, superior orbit.
Insert upper eyelid.
And its action.
What's it called?
Levator.
Raises the eyelid.
Repeat, repeat, repeat.
So a person comes into your
office and has a droopy eyelid.
What nerve are you
going to say is out?
STUDENT: [INAUDIBLE]
MARIAN DIAMOND: No.
Good guess.
Third.
Third nerve for the
eyelid here We're
only going to take a
few of these this time.
When we get to the nervous
system, we'll take more.
But third nerve innervates
your levator palpebrae muscle.
Now how are we going
to close our eye?
We've got it open.
But there's a lot you can learn
from just looking at somebody.
Pretty soon, when we get
all your cranial nerves,
you'll do it with each other.
You'll test every one
of them and be sure
that they're all functioning.
Very simply.
So let's now take the
orbicularis oculi.
This one's going to
close the eyelid.
So we'll have it originate--
got some new terms here.
Here's our orbit.
And here, this is medial.
This is lateral.
We'll have our medial
palpebrae ligament.
Medial palpebrae ligament.
And laterally, we'll have the
lateral palpebrae ligament.
So this muscle will originate at
the medial palpebrae ligament,
and will insert at the lateral.
And its action will
be to close the eye.
So we can see its muscular
arrangement coming around
in the lid like this.
And when these muscles contract,
then the eyelids close.
But it's fascinating, the
two controls on this factor.
It's capable of a
blink, very fast.
Just blink.
To do the blinking as fast,
it's just this muscle, this way.
But when you
squeeze your eyelids
to protect them
or you're swimming
and you don't have your
glasses, you want to squeeze.
Then you use the whole muscle.
You don't just blink.
But isn't it amazing
how fast that blink is
and to think of
muscles contracting?
You think it's faster
than a hummingbird's wing?
STUDENT: No.
MARIAN DIAMOND:
You don't think so?
[LAUGHTER]
OK.
I just think it's
amazing that you've
got that muscle with its double
innervation, and one of them
just like that.
The other one's slow and
sustained and can keep it.
Beautiful design
just in your eye.
So that gives us the
muscles for the eye.
Let's see.
Which one do we
want to take next?
We have lots of
these muscles today
if we can get them all in.
Let's take a cheek muscle.
Let's just move
down to the mouth.
So we'll take a cheek muscle.
Take the buccinator.
Have you heard of
your buccinator?
What does buccinator mean?
Trumpet.
Does anybody play a trumpet?
Yes.
You know your
buccinator then, do you?
Sure.
Cheek muscle.
Really contracts to get
the air directed to go out
through your mouth, right?
So it means trumpet.
So it will be originating
from the maxilla and mandible.
So we'll have it--
if mouth is here, it's coming
in from maxilla, mandible.
And it's coming in to
the angle of the mouth.
It will insert at the
angle of the mouth.
So you have the same coming
from the opposite side.
Angle here to insert in.
So function or action.
Well, you can see easily
that if it's going to pull,
it can help you smile.
It can pull out the
corners of your mouth.
But it can also compress
the sides of the cheek.
Compress cheek to
force air out mouth.
And that's where it
gets its name trumpet.
Squeeze it.
It's useful for when you're
chewing and you chew down,
and the food goes laterally.
Buccinator can contract and push
it back in between the teeth.
In chewing, keeps
food between teeth.
Between teeth crowns, let's say.
We don't want it aside.
All right?
So that's a buccinator.
Now let's get the--
the next one will be--
which one do we want to take?
The orbicularis oris,
orbicularis oris.
Orbicularis.
So you can tell where
it's going to be.
This will be around the mouth.
It's going to close the mouth.
And again, the origin
will be cheek muscles.
See, I'm not giving you
all the cheek muscles.
Cheek muscles including
the buccinator.
No, when I meet my former
students over at UCSF
and they say, we thought
we were getting a lot here,
we didn't realize how
much there is to get,
and they're getting
it over there.
This is just the beginning.
Insertion here will
be the contralateral--
we'll define it in a moment--
contralateral angle of mouth.
Think of its function.
See why it's got to go
to the opposite side.
So if I have a mouth here and
I have my muscle over here,
coming in from
cheek muscles, it's
going to insert clear over
on the opposite angle.
Come all the way around.
We'll do this.
And the same here, all the
way over here to insert.
And then you've got it
coming from the other side,
and that's got to go
around and insert here.
That's contralateral,
opposite side.
So obviously, when it contracts,
it's going to close the mouth.
Now what closes the jaw?
You have two muscles
to close the jaw.
So you know what
your jaw bones are,
so you know where to expect it.
Muscles of jaw.
We have two.
One is the temporalis.
Temporalis.
And one is the masseter.
Masseter.
Masseter means chewer.
Temporalis, you know.
So we're going to have--
here's our jaw bone.
We've got to make use
of its attachments,
so we're going to have
the temporalis originates
on the squamous portion of
the temporal bone and inserts
on the coronoid process
of the mandible.
Makes sense.
It's got to come
to the mandible,
and this is available
for an attachment.
So origin for temporalis
equals squamous portion
of temporal bone.
This is temporalis.
And insertion will be the
coronoid process of mandible.
And what's it going to
do when it contracts?
Just what this
little spring does.
Contracts, closes jaw.
But it has some support.
How much pressure do you
think you can exert when you--
I mean, you put your
pencil in there.
If it's wooden, you'll just
crunch it right in half.
Have you ever tried that?
No, because I look at your
pens, and they're all plastic,
so I recommend you don't try it.
But how much
pressure do you think
you can exert with these
two muscles crunching down?
Somebody has said
it's about 200 pounds.
That's a lot.
Remember the boxer who bit
off the other boxer's ear?
[LAUGHTER]
Yeah.
Gives you an idea of
200 pounds of pressure
taking that off, right?
Powerful muscles.
So what's your other one?
The masseter.
And the masseter
originates then-- see,
we've got to use our bones.
We develop them.
Here's zygomatic arch here,
made of these three bones,
commonly called the cheek bones.
Very fashionable to
have high cheek bones.
So originates on, as you
knew it before, cheek bone.
It's now our zygomatic arch.
And it's got to close the
jaw, give all that pressure.
So it's going to
insert on the angle
and the ramus of the mandible.
Remember the ramus?
Remember the angle?
So it's just coming down
a little-- almost square
coming down to insert on
ramus and angle of mandible.
And its function then is to
close the jaw with great force.
You know why I feel inspired
to teach you anatomy today?
I got an email from
a friend who was
in a southeast Asian country.
I won't name names.
I'll just give the status of it.
And he was told that he
had torn his Achilles
tendon from his calcaneus, and
it needed to be sewn back up.
So he knew he didn't want to
stay there and have it done,
so he went someplace
else to have it done,
and they said, what you really
have is an infected blister.
You think you could to identify
the calcaneus and Achilles
tendon versus an
infected blister?
I hope so, but it
sure inspires me
to give you basic,
honest-to-goodness anatomy.
Imagine if he didn't have any
question, and gone through
and had his Achilles
tendon operated on?
Dear me.
Anyhow, I thought
that's a good story
to tell you to
inspire you to want
to learn your anatomy well.
Where are we?
We're finishing
with our lower jaw.
Now let's look at some muscles.
These are big muscles that are
attaching the upper extremity
to the trunk.
Muscles-- I'm just
putting large ones,
because there are so many small.
Large muscles attaching
upper extremity to trunk.
We're going to take--
whoops-- two posterior
and one anterior.
Let's just quickly give
you the superior posterior.
And the name of this one
will be the trapezius.
Trapezius, It's because
it has a trapezoid shape.
So let's just quickly see how
it would have a trapezoid shape,
see how far we get.
But I don't want to get
too far behind here.
Every time I tell a
story, I lose some time.
So here we have the occiput.
Here we have the
vertebral column.
And we have the
cervical vertebra
and the thoracic vertebra.
And we'll have the
spine of the scapula.
Spine of scapula.
And what will have the origin
will come from the occiput
and from what's called
the ligamentum nuchae.
What in the world's
the ligamentum nuchae?
Liga-- L-I-G-- ligamentum--
I want lig.
Ligamentum nuchae.
I'll give a definition
of it, and then we'll
stop and give our
slides and continue.
It's a ligament that
attaches all the spines
of the cervical and
thoracic vertebrae.
It runs down.
Ligamentum nuchae,
connecting all the spines
of thoracic and
cervical vertebra.
Let's show slides then, and
we'll continue with this.
And don't forget
131 A right after,
because we start
10 minutes past 12.
Hmm.
I don't see a pointer
here this morning either.
Where is it?
[LAUGH]
AMELIA: [INAUDIBLE].
This is one.
MARIAN DIAMOND: There's one.
OK, Amelia.
Thank you.
Yeah.
We're fine.
All right.
Here's your frontalis
muscle, and you've
had the galea aponeurosis.
You see a little
of it coming here,
but it's originating from
the galea aponeurosis,
and then will be
inserting in the muscles
in the superior aspect here.
So when you contract
the muscle, you
raise your eyebrows and
wrinkle your forehead.
Here's your orbicularis oculi.
You can see the
fine muscles of it
that will make the eyelid
move very fast for a blink,
and then when you
scrinch it hard,
these will come into play.
Here's your orbicularis oris.
Your buccinator will be
coming in from the side
to the angle of the mouth.
Then the next one.
Here's your sternocleidomastoid.
Here's your sternum.
Here's your clavicle, or cleido.
Here are the two heads.
Here's the sterno, the
cleido coming together
to insert on the
mastoid process.
I use this picture to show you
a little occipitalis up here,
and then its galea
aponeurosis, which
will continue over, and then
become the frontalis here.
Here you can see a little
bit more of buccinator.
No one picture shows everything.
Here's your deltoid, the
base of it here, coming down.
At apex will be on
the humerus down here,
and the base is both on the
lateral clavicle and lateral
spine of the scapulae
on the other side.
And the next one.
And this-- oh, we didn't
get to the pectoralis major,
but we will next time.
But here's the deltoid,
which we did mention.
All right?
We'll get all of this soon.
All right?
We have one more minute.
Do we have one more slide?
Yeah.
This is showing the
trapezius coming here.
It's originating up here
at the occiput, coming over
to insert on the
spine of the scapulae,
and it has coming up
from the thoracic spines
the ligamentum nuchae
coming in this direction.
So you're going to be
forming a trapezoid when
you get both sides.
Here's the deltoid.
And we'll continue
with this next time.
Have a lovely weekend.
