MARIAN DIAMOND: Good morning.
I don't know if I said
in the introduction,
but I expect all of you
to get As in this course,
and we come pretty close to that
at the end because we review
and we review and review.
So if you do your
part, I'll do my part.
My heart's in the right place,
and I'm sure yours is too.
All right, with
that introduction,
let's go back and pick
up cells, all right,
because the cells are the basic
anatomical unit of the body--
basic anatomical unit of body.
It's very hard when you're
teaching a first grader what
a cell is and even
giving this description,
but obviously, for
you, it's easy.
Cells come in many
sizes, different shapes,
and we're only going to, in this
course, discuss a few of these.
Let's take sizes first.
Let's take the smallest, the
largest, and the longest.
And interesting enough,
all three of these sizes
are in the nervous system.
So where do we
find the smallest?
These will be just names to you,
but as we study the structures,
they'll be repeated again.
So right now, we're going
to find the smallest--
will be four micra.
What's a micron?
A micron is 1,000th
of a millimeter.
A 1,000th of a millimeter
equals one micron,
so it gives you an order of
magnitude of the dimensions
of the cells we're
talking about.
The smallest form will be the
granule cell in the cerebellum.
The granule cell-- we'll
show a picture of it.
You saw it last time-- granule
cell in your cerebellum.
The largest will be the anterior
horn cell in your spinal cord.
It's 135 micra on average, and
this will be the anterior horn
cell in the spinal cord.
Just to give an order of
magnitude to compare it with,
what's the size
of the human ovum?
You ovulate each month.
What's the size?
120 micra equals a human ovum.
Obviously, I'm putting
it in there only
to let you know that,
at that magnification,
you can see the dimensions
with the naked eye--
see with naked eye.
All right, now
the longest cell--
the longest cell is
the pseudounipolar cell
in the nervous system.
Pseudo-- what does pseudo mean?
Pseudounipolar cell--
pseudo means false.
Unipolar means one pole.
So what kind of cell is this?
It has a false pole.
Well, this cell is going to have
a process coming into the cell.
Here's the cell body, and
then a process going out.
So let's say that the end of
this cell is in your big toe.
Think of your big toe.
Can you see it down there?
Don't look at it.
You know it's there, don't you?
All right, so this is going
to be coming from the toe,
and the information is going
to come up into this cell,
and it's going to
come in this pole--
this is my cell body--
and this cell is going to be
in the lower vertebral region
is all we'll call it now--
lower vertebral region.
So we've come all the way up
this one process from our toe,
all the way up to here,
and now the impulse
has to go back out again and
go up to the lower brain stem.
So where does the
pseudo come in?
Well, if you just saw
the pole, you would say,
well, it's only got one
pole, but functionally, it
has in and out.
Therefore, it's called a false
unipolar, and how long is it
since we said it's the longest?
Well, let's just take an average
height of an individual-- say,
5 feet, 9 inches
tall on average.
So you're going to consider
coming up the leg--
roughly three feet--
another two feet here,
so you have a cell from a single
cell body that's roughly 5' 9".
I think it's amazing, right--
longest cell-- a
pseudounipolar cell.
But that gives you an
idea that sizes can vary.
Now, shapes vary too extremely.
The greatest number
of shapes, again,
will be in the nervous
system, so we're not even
start with those.
You've had just a couple of
them here, but not in detail.
You'll get them later
to varying degrees.
But let's just look at shapes.
Let's take a squamous cell--
squamous.
Squamous, literally
translated-- it is a scale.
You've seen a fish scale.
So it will be flat, and
example will be in a capillary.
So an example in a capillary--
capillary is your
smallest blood vessel.
Start to abbreviate.
Blood vessel is going to
be just BV from now on.
So it will have this flat cell,
but it's surrounding a vessel,
so sort of like this--
and that will be your
cross-section of a capillary--
so that substances can go
in and out to the tissues
easily from the blood vessel.
We don't want much of
a wall in our cell.
When we need a cell
to be conveying fluid,
we could have a cuboidal cell.
Cuboidal cell-- the height
will equal the width,
just as it says--
cuboidal.
Where are we going to
see cuboidal cells?
Certainly, we don't
want them down here
at the finest point of
our vascular system,
so we'll have them lining ducts
that are conveying fluids.
So you're sitting there now.
You're pouring saliva
out into your mouth,
so the ducts from salivary
gland is an example.
Ever thought about your
salivary ducts before?
And then we will need a
different type of cell
for our digestive system.
We're pouring all those
hamburgers, milkshakes,
all that rough stuff
into our system.
We don't want a simple cell.
We need more than
a cuboidal cell,
so we'll have a columnar cell.
So the length will be
greater than the width--
columns.
And our example will
be the digestive tract.
So there are all kinds
of these and different.
These are just simple
cuboidal, simple columnar.
You can have stratified
columnar, stratified cuboidal.
You can have
stratified squamous.
Your skin is all
stratified squamous
when you have many
layers of these.
These are just
basic, simple layers.
You can have stratified--
many layers.
By the time we finish, we'll
be able to name any tissue,
and you'll tell me what kind
of epithelium it has in it.
You do.
I know it because we keep
repeating it, repeating it.
You can just say, well,
it does this function.
Therefore, it should have
that kind of cell, right?
So with this introduction
to our cells,
let's now go back to our
skeleton and our divisions
of our skeleton,
which we said we
had the axial and the
appendicular skeletons.
We're going to take the
axial skeleton today,
but we'll give our definition
between the axial skeleton
and the appendicular skeleton.
So the axial skeleton
just means that it
will run through the
medial access of the body.
So if we put a head and
the main axis of the body,
we can see that the skull will
be part of the axial skeleton.
So we'll study the skull
today and all the bones
that make up the skull.
But in addition to skull bones
within the skull are what
are called your ear ossicles--
your ear bones-- the
smallest bones in your body.
So they're put in with
the axial skeleton--
the ear ossicles.
For you to be hearing me now,
your ear ossicles are moving.
As we move down from the
skull, the next bone--
we'll talk about
it in a moment--
we're just going
to name them now--
in the neck that will
be the hyoid bone.
How many have heard
of your hyoid bone?
As we go down, we'll have
the sternum and the ribs
because they are attached.
And the sternum and
the ribs constitute
what's called the thorax
or a thoracic cavity.
So we see here's our sternum.
Here are ribs.
The cavity beneath is
the thoracic cavity.
And then we've got to
take the structure,
but it's on the posterior
surface that runs in the media
all access of the body--
the vertebral column, so
we'll just call this--
well, the vertebral column
has got to come in here,
so we'll put it here.
So this gives us the bones
of the axial skeleton.
Now, the appendicular
skeleton are these appendages,
which hang out here.
So we've done this one,
and we have these out here,
so we have the upper extremities
for the appendicular skeleton,
and there are girdles.
You've perhaps never heard
that term applied to the body
before.
So with the upper extremity,
what will the girdles be?
It will be that part
of the skeleton which
attaches the upper extremity
to the axial skeleton.
So the clavicle and
the scapula make up
what's called the
pectoral girdle.
The pectoral girdle equals
the clavicle and the scapula.
The lower extremity
also has a girdle.
The girdle for the
lower extremity
is called the pelvic girdle.
We talked about
pelvis last time when
we talked about bone marrow.
So the pelvic girdle
consists of three bones.
We'll talk about it later, but
now we're just listing them.
Pelvic girdle equals the ileum--
we had the iliac crest--
the ilium, the ischium.
Right now, you're
sitting on your ischium.
You say get tired of
sitting, tailbone is sore.
You're not sitting
on your tailbone
because there's your tailbone.
You're sitting on your ischium,
so let's be correct anatomists.
Ischium and the pubic bone--
so these three
bones constitute--
ileum, ischium, and the pubic
bone is around here in front.
We'll talk about these
when we discuss this later,
but you have the general idea of
an axial skeleton, appendicular
skeleton attached by girdles--
very simple concept.
So now we want to go
back and see the details
of these phenomenal structures.
So let's begin with the skull.
The skull has two
major components.
It has commonly called just
the skull cap, technically
a calvarium.
And the calvarium
has some eight bones.
And then we have
the facial bones,
where we have about,
oh, 14 to 15 bones.
We'll see how many we
add up as we go along.
So let's begin
with the calvarium
and start with the frontal.
Maybe it's easier to name
them and then describe
each one of them.
We have the frontal, we have
the parietal, the temporal--
what's the next one?
Occipital, the sphenoid,
and the ethmoid--
so let's see what we can
learn about these bones
and how they form
your calvarium--
start with frontal.
Well, easy enough-- we
said previously forehead,
so it forms the forehead.
And then we'd have to
go inside the skull,
so you just have to
take my word for it.
It will form the anterior fossa
of the base of the skull--
anterior fossa of base of skull.
The frontal bone, if I
were to drill right here,
I find a sinus, a cavity--
the frontal sinus.
Sometimes you see
that on television.
They're telling you what to
use to clear out your sinuses,
and they show you
a frontal sinus.
So this gives you some of the
parts of the frontal bone.
The parietal bone--
parietal means wall,
so it's going to
be on the side--
there are two of them.
The frontal has fused,
so you only have one
as an adult. Two parietal--
wall-- and I want to introduce
the term suture to you
now because a suture is the
joint between the skull bones,
and it's important that
you understand them.
Suture-- the joint--
let's put an s--
between the calvarium bones.
So if we're looking down
at the top of the head,
and this is anterior,
this is posterior,
we're going to have--
here, I can make this
a little bit bigger.
So here, I have my frontal
bone, have my parietal,
and have my occipital
with our foramen magnum,
and I've put in the sutures.
This one will be the coronal
suture between the frontal
and the parietal.
This one will be the
lambdoidal suture.
Why lambdoidal?
Because it looked to the
early anatomists like one
of the Greek letters lambda,
so it looked like a lambdoidal.
And the one in the mid-line is
called the midsagittal suture.
And all these are very clear
and nice in your skulls.
Now, they all fused
in your skulls.
How did they look when
you were a baby when
your brain was growing so fast?
You had two frontals.
You had parietals.
I'm just going to put
them in a crudely.
So this would be frontal.
This would be frontal--
parietal, parietal.
And we have connective
tissue growing between them.
That's connective tissue.
It's a thin layer.
What do they call it
in the young baby?
They tell you not
to poke your finger
in the top of a
young baby's head.
What do they call it?
Soft spot-- that's
the common term.
Equals a soft spot--
technically, it's a fontanelle.
It's an anterior fontanelle.
I'm only giving one of them.
Why do we have to have these?
Because the brain is growing
very fast after birth.
So you don't want tight sutures.
You want the give, so
this allows for the give.
And then as you become older,
then the sutures become firmer,
but fontanelles are very
important in the infant.
This is infant skull.
So that gives you an
idea about the frontal.
The word about a
parietal-- it doesn't
have many characteristics other
than just forming the wall.
Let's next take
the temporal bone.
The temporal bone
has four parts.
The first part is called
the squamous portion
of the temporal bone--
squamous.
Excuse me.
What does squamous mean?
I just taught you--
flat.
So it can mean flat,
whether it's a cell,
or it can mean flat,
whether it's part of a bone.
So this is very thin, flat part.
So it's right here--
temporal-- the squamous
portion of the temporal bone.
And if you are taking
a lab, take a skull
and hold it up to the light, and
you could see that it's quite--
I don't know if you can see it.
I can see it.
It doesn't help, I guess.
But just here, it's so thin that
it's essentially translucent.
So if you're going to get
hit in the head at any time,
don't get hit in the
side of the head.
You've got a
concussion immediately
when you crack that part
of your temporal bone.
Get the back where it's
heavy and thick, right,
if you have time
to think about it.
All right, so
squamous-- well, I did
once, I'll tell you, just
surfing in Hawaii learning how
to stand up and surf, and there
so many people surfing, and all
of a sudden this head
came up in front of me
when I was coming down.
And fortunately,
he turned his head
over because I
would have clipped
him right in the squamous
portion of the temporal bone.
So you never know when
it's going to be important.
All right, the
squamous portion--
let's take the
mastoid portion next.
Mastoid portion
of the temporal--
does anybody know what
the term mastoid means?
Greek-- it means breast.
What in the world
is a breast doing--
that just shows these male
anatomists saw a little bump
in the back of
the head, and they
called it the mastoid
portion of the temporal bone.
So it means breast.
Isn't that fun to learn names?
But where do you hear that
term with human females?
Mastectomy, right?
Removal of the breast--
CA of the breast?
Mastectomy.
So it's good to
know in your terms.
Where in the world did
mastectomy come from?
It actually--
related to breast--
this is where removal of female
breast for cancer, all right?
But your mastoid process
has a sinus in there,
so your mastoid has
a sinus, and it's
an important part of
your body because it
connects to your middle ear--
connection.
And when we study
the middle ear,
we'll see that it
has a connection
with your nasal pharynx,
which we'll get later--
connection with nasal pharynx.
Why you study anatomy--
you get these connections.
So if you get an
infection in your pharynx,
it can go into
your nasal pharynx.
It can go into your middle ear.
It can go into
the mastoid sinus.
And we used to get skulls,
where the only way they
could clear out an
infected mastoid process
was surgically--
just go in and cut it all out.
So we'd get skulls with
no mastoid process here.
What do they give today
to clear out infection?
I'll wait for answers.
What do they give
for infections?
Antibiotics?
How about penicillin?
They give penicillin
so you don't
have to go in and
clean this out anymore.
You don't see skulls
that way, but we
use to see them, all right?
So it's important to know
how an infection gets
back here into a
temporal bone when
you've got an infection up in
your nasal cavity, for example.
All right, what other part do
we have of the temporal bone?
We have the zygomatic process.
The zygomatic process-- it's a
lot of words to just mean bar.
Let's see, we're one, two--
zygomatic process-- so we'll
say that this is the posterior
portion of your cheek bone.
Palpate your-- feel
your cheek bone,
and your posterior
portion here is coming off
your temporal bone, coming up.
Here you had your
squamous portion.
You had your mastoid portion.
You have the zygomatic
process forming the posterior
part of cheek Bone
Now, we have one more
part of our temporal bone.
Or a fourth part will
be the petrous portion
of the temporal bone--
petrous portion.
Now, again, I won't see
this from the outside.
We'll see it in a moment
when we draw the inside.
So petrous refers to hard.
Most of the skull
is hard, and I don't
know why they gave
that this name,
but it houses your inner ear.
Your petrous portion
of your temporal bone
houses the inner ear.
And we'll see that again
when we talk about ears.
So that gives you
your temporal bone.
Your next one is
your occipital bone.
We've already talked about one
of the major characteristics
of the occipital bone.
What was that?
I don't hear you.
What did we say about
the occipital bone?
Foramen magnum, exactly--
you had the big foramen--
most characteristic
thing, right?
Your occiput-- the back--
look at how thick
it is in comparison
to the squamous portion
of your temporal bone.
So it has the foramen
magnum, and that's
where the spinal cord
to attach to brain.
But the occipital bone also
has the ability to articulate--
it has articular processes--
to articulate with the
first cervical vertebra.
So the occipital
bone articulates
with first cervical--
cervical means the neck--
cervical vertebra.
What do we call the
first cervical vertebra?
What holds up the world?
Atlas-- the first
cervical is the atlas,
which holds up the skull.
It's sort of fun to be creative
when you're naming bones,
right?
So with this, we've
covered the major bones
that you can see
clearly, but we have
the sphenoid and the ethmoid.
And I lost my eraser.
Here it is.
And these, as I
mentioned before,
you're going to have
to use your books
to see because, for the
most part, they're inside.
Let's look, to start with,
at the floor of the skull.
And this will be anterior.
This will be posterior.
So we said that the
anterior cranial fossa
was going to be our
frontal bone, so we'll
have frontal bone in here.
Let's see if we have
enough colors to do this--
maybe, and maybe not.
So let's make the
frontal bone here.
So frontal bone will be pink.
Then we'll put in what
shows of the ethmoid
in the base of the skull.
This is all base of skull.
And then we have the sphenoid.
Blue is our sphenoid,
and now we can
put in the petrous portion of
the temporal bone in here--
white-- the petrous
portion of temporal bone.
And that leaves our
occipital back here
with it's lambdoid shape--
occipital.
So with this drawing, then, we
can come back to our sphenoid,
and it's called the
keystone of the floor
because it keeps the
other bones in place.
Have you ever built an arch?
Do you know what the
keystone of an arch is?
Sure, you've got
an arch like this,
and you've got the
bricks like this.
You take out this brick, and
everything else falls down.
That's a keystone.
The sphenoid is the
keystone of the floor.
Now, the sphenoid
will have sinuses--
sphenoid sinus--
and it will form
the lateral wall of the orbit.
That's your eye socket.
And that's on the floor.
It's going to send out parts
to be in the lateral wall.
And now it will form what's
called the Turkish saddle.
How many ride horseback?
How many horns on
an English saddle?
None.
How many on a Western saddle?
One.
How many on a Turkish saddle?
Four.
So we're going to
see four processes.
These early anatomists
had colorful imaginations.
Now you see these
little processes here
called clinoid
processes, and they
surround one of the most
important structures
in your body.
When you study this in detail,
you'll see all the membranes.
What structure is
found right here?
The pituitary.
What's pituitary?
I made you look up, didn't I?
Both the interior and
posterior-- so we'll
just say the pituitary gland.
So now, if anybody asks you,
where is your pituitary gland,
what are you going to say?
How are you going to tell them?
You say put one
finger at the bridge
of your nose, your other
finger at the tip of your ear--
superior part.
Do it.
Sure, she's doing it.
You've got the superior
part of your ear.
Where those two points meet
in the middle of your head
would be your pituitary, but
it sits in the Turkish saddle--
the sella turcica--
very important landmark
in your skull.
We don't have time
to go into that now,
but it gets you that it's
in the sphenoid bone.
Now, let's look at the ethmoid.
We're only giving briefly things
about these, so the ethmoid--
we had it in orange over there--
the part that we see from
the base of the skull.
There's lots more to it.
So right here, what the
ethmoid is developing into--
what this ethmoid mean?
It means sieve.
You know what a sieve is.
Fluid goes right
through it, right?
So this ethmoid here is
called the cribriform plate
of the ethmoid
that you see there.
There's lots more to the
ethmoid beneath that,
but this is the
cribriform plate.
You ever played
the game cribbage?
You have a board
with little pegs.
This is filled
with little holes.
It's a sieve.
Why does it have all
those little holes?
It has all those little holes
so you can bring your smell
impulses up into your brain.
So these little holes convey
your olfactory nerves.
The olfactory nerves enter
skull via the cribriform plate.
So you can see why boxers may
have a problem with smell.
Get hit in your
head often enough,
and you just ruin all
those little nerve fibers
coming through from your
nose to your brain, right?
All right, he blinked
me to tell me it's time.
Lots more to give, but we've
got to give your slides.
What do you think?
Fascinating, isn't it?
And you've lived with
it all this time,
and how much do
you know about it?
Take it for granted
if it doesn't work--
such a shame.
All right, first slide, please.
Here we are.
Let's review, then,
what we've said.
We talked about the granule
cells of the cerebellum
being the smallest
cells in your body,
and they do look like
little granules, don't they?
Those are all little cells.
So here, they're just piled
together-- millions of them.
This is just another
type of nerve cell,
but these are the smallest--
four mu.
Next one-- now, this is
an anterior horn cell.
For me to be moving
this pointer now,
the anterior horn cells in my--
well, this is C8, T1.
My vertebral column would
be firing in my spinal cord.
See how big they are--
anterior horn cells--
135 mu.
Next one-- this is just--
I showed this one previously,
so you see simple epithelium
here--
squamous.
This is on a valve in a vein,
just shows it more clearly
than if I take a capillary.
And the next one--
this is a cuboidal-- not
quite picture perfect,
but as close as we come to it--
lined by the simple
squamous epithelium.
And the next one--
and then these are
nerve cells to show
that we have the greatest
variety of shapes and sizes.
This is the one
that we mentioned,
where we'd have a process in our
toe that goes all the way up.
See, it looks like
a single process,
but it conveys
information in and out,
therefore
pseudounipolar, and then
takes it on up to the brain.
And the next one--
and here we are with our
axial skeleton with our skull,
and within the skull,
we have our ossicles
from the auditory system.
We'll have the hyoid bone
beneath the mandible here.
We have the vertebral
column in back.
We have the sternum,
the clavicle.
We see the scapula
and the clavicle
make up the pectoral girdle--
our upper appendage.
Here's our pelvis--
the pectoral girdle--
the ilium, the ischium--
this is what you're sitting
on-- your ischial tuberosities--
and your pubis, connecting
the lower extremity
to the axial skeleton.
And the next one--
this shows your fontanelles.
Here we're forming with your
frontal bones, parietal bones,
and the anterior fontanelle.
Did you ever know it was
that big that you can
see you have connective tissue?
Your cerebral cortex is growing
at that slope of a curve
until about 10 years
of age after birth,
so this won't fit
tight until later.
And the next one--
and now we show the
frontal bone from front
that we see it forms the
superior wall of the orbit.
We have the nasal bone.
We didn't get to all
of facial bones yet,
but we can just say that
the sphenoid will form
the lateral wall of the orbit.
The ethmoid will
form the medial wall
because, if I go
straight through here,
I'll be at my cribriform
plate of the ethmoid.
This is part of ethmoid.
This is part of ethmoid,
and zygomatic arch is here,
but the zygomatic process from
the temporal bone is here.
Your cheek bone is made
up of three bones--
zygomatic process of
temporal, zygomatic bone,
zygomatic process
of your maxilla.
Next one-- we didn't quite get
this far, but this will show--
this is a squamous portion.
See how big and flat it is.
27 is very thin.
Here is the zygomatic
process of the temporal.
Here's the mastoid
process of the temporal.
The petrous portion is inside.
This is your external
auditory meatus.
It's a tube.
This is a depression.
This is which joint?
What bone is this?
Come on-- mandible.
What bone is it
articulating with?
Temporal-- so what
do we call the joint?
Temporomandibular-- say it.
Learn to speak the
language because we'll
wait for you if you
don't because that's
the most important thing you're
going to be taking with you.
You've got to learn
to communicate.
You may know, oh, I know it,
but I don't know how to say it.
So we say it here.
All right, it says
exactly 12 o'clock.
We made it.
All right, enjoy.
Have a nice holiday.
