PROFESSOR: All right
with that, let's
begin with our thoracic cavity.
Have you thought about your
thoracic cavity today? .
No, but let's begin.
We said that the thoracic
cavity had sternum,
had costal cartilages, had
ribs, and the vertebral, right?
So let's look at the structures
in a little more detail now.
Do you want to take
these off during class?
I think that's fine
to have them up there.
Because I'm not going to write
the names on the blackboard
anymore, but this way they'll
be up when you come to class.
You don't have to wait
for me to get them and go
through my writing.
And so these are the names.
Let's see now.
We want the thoracic
cavity and we'll
have the sternum, the parts of
the sternum, three major parts.
This whole thing is a sternum.
I'm going to put it
down here because I want
to write for the other parts.
And we have the manubrium,
the first part, manubrium.
We have the body.
And what's this part called
that looks like a sword?
"Zy-phoid" or xiphoid, whichever
you like, xiphoid process.
This person, it's sword-like,
as where xiphoid comes from.
Now we have what's
called a jugular notch.
up at the superior
aspect of the manubrium.
This is the jugular notch.
What's jugular mean?
It means throat.
So we're going to
see the jugular vein,
we're going to see
this is the notch.
You can feel it.
Palpate it there so
you know where you are.
Feel the indentation,
mid-line there.
That's your jugular notch.
We have the sternal
angle, where the manubrium
meets with the body.
This is the sternal angle.
It's the most commonly
fractured area of the sternum.
If you get hit in
the front, it's
the sternum that gets--
the sternal angle that
gets fractured.
So most frequently
fractured area of sternum.
And now we have to attach the
ribs via the costal cartilages.
We have 12 ribs, seven
of them are true.
True ribs are one through seven.
Why are they called true ribs?
Because their costal
cartilage attaches directly
to the sternum.
Then we have five false ribs.
They don't attach
directly to sternum.
Three of them attach to the
superior costal cartilage.
They just come up and insert
in the costal cartilage.
Three of them, to
superior costal cartilage.
And two of them do not
attach anteriorly at all.
They're called floating ribs.
So we have two floating
ribs, no anterior attachment.
So we can show how
these are attached.
We have the first rib.
Don't put it clear
up because we've
got to bring the clavicle in.
Right here, we're going to
have first costal cartilage.
And the second costal cartilage
is at the sternal angle.
At sternal angle, in here.
And then the third, fourth,
fifth, sixth, seventh.
So those are our
true ribs attaching
through the costal
cartilage to the sternum.
But the next ones then, if we
have a costal cartilage coming
in from the seventh,
here, we'll have
the costal cartilage
of the eighth attaching
to the seventh.
And the ninth attaches
to the eighth.
And the 10th to the ninth,
and so forth, the superior
cartilage.
And then we'll have the
floating ribs 11 and 12 here.
All the ribs then have a
posterior attachment to what?
Where do the ribs attach?
What did we say in
the last lecture?
Which vertebra have facets
for rib attachments?
Thoracic, so all ribs
attach posteriorly
to thoracic vertebra.
So that gives us our rib cage,
or thoracic cage, technically.
Now as we look at the
appendicular skeleton--
It's hard to say which
side of this eraser works,
neither very well.
Let's switch that one.
That's much better.
So as we start with the
appendicular skeleton,
we'll start with
the pectoral girdle.
And the pectoral girl
consists of two bones.
We've seen these, the clavicle
anteriorly and the scapula
posteriorly.
Clavicle and scapula.
The clavicle will
articulate with the sternum
at the manubrium.
So we have-- let's
put a clavicle here.
This is medial, lateral.
You can see that we have two
curvatures on the clavicle.
We have this curvature, which
is medial, which is convex.
And we have this curvature,
which is lateral,
which is concave.
So take a moment,
palpate your clavicle.
Start it medially, feel it
curving forward, then it really
dips in as it goes
laterally, right.
Take it clear laterally.
You're staying too medial.
Take it clear over.
You feel the difference?
Know your own body.
So when someone comes
to you and says,
well I've hit myself
here, you could say,
well it's supposed to do this
and this, and yours is not.
So you'll always have
your body as a foundation
from which to work.
So if this medial articulation
will be the sternoclavicular
joint.
So x, we have the
sternoclavicular joint.
And at xx laterally, we're going
to have the clavicular acromiol
joint, or the
acromiolclavicular,
we could call it.
Let's call it a acromi--
because the acromial's going
to be part of the scapula.
So laterally, we'll have the
acromiolclavicular joint.
That gives you just basic
landmarks for your clavicle.
But I think it's fascinating
that your whole upper extremity
only articulates with
the axial skeleton
here at this
sternoclavicular joint.
Isn't that amazing?
All this is held up by muscles.
The only bony joint is here.
All right let's move
into the scapula.
Scapula will be posterior.
It's thin.
It will lie over the second
to 7th ribs, posteriorly.
Lies over second to
seventh ribs, posteriorly.
It is triangularly shaped.
And this is a posterior view.
We'll have the spine--
let's take this one--
the spine of the
scapula expanding
into this acromial process.
So we'll have the spine coming
across and then expanding
into an acromial process.
Spine and acromial process.
And so it will divide
the posterior scapula
into two major segments,
supraspinous fossa
and infraspinous fossa.
So this is our
supraspinous fossa,
and this will be
our infraspinous.
We give these because
we'll have muscles here.
Spinous fossa.
Then we want to make
a indentation here.
This will be what's
called the glenoid cavity.
The glenoid cavity.
Glenoid cavity.
What occurs at the
glenoid cavity?
What's this?
What is it?
Humerus, sure.
The head of the humerus
articulates with the scapula
at the glenoid cavity.
So at the glenoid
cavity we have the head
of humerus articulates here.
That's on our posterior view.
On our anterior view, we'll
have a little process that will
stick up something like this.
This little process is
called the coracoid process.
You had a coranoid process
on your mandible, right.
A condylar process
on the mandible.
Here's a coracoid
process on the scapula.
And this will receive
the short head of biceps
originates here, just to give
it some dynamics to remember it.
But that, an anterior view.
And you can't see it
underneath the scapula.
This is anterior.
It's here underneath
the clavicle,
medial to the head
of the humerus.
All right.
So much for our scapula.
Let's go on then to
the upper extremity
Where we'll have the arm,
which we call the humerus.
And it will have a head.
It'll have a greater tubercle.
So this is the head.
Here's the greater tubercle.
This is a posterior view, so
you could see the head here,
greater tubercle out here.
And then we'll have
the shaft coming down
like this, which will have
the deltoid tuberosity.
And we'll have two necks.
We'll have the anatomical
neck between the head
and the greater tubercle.
This is the anatomical neck.
And we'll have
the surgical neck.
What do you know about
the surgical neck?
How many have broken
their humerus?
No one?
Do you know where you broke it?
Distal or proximal?
Proximal.
That's more unusual, right?
The fracture, when it
comes to the humerus,
most commonly comes
at the surgical neck.
Fracture most common
at surgical neck.
So it's important to know
these vulnerable spots.
Usually in class, I've never
had one had a proximal.
They have the distal.
If we look at the
distal end, then--
Let's break this and bring
this down to a distal end.
We'll have one and two.
One will be our medial
epicondyle of the humerus.
Medial epicondyle, and two,
the lateral epicondyle.
You can palpate these easily.
Just put your hand in
the anatomical position,
feel them there, big bumps.
Here they are.
Anatomical position,
here is medial.
Epi, what does epi mean?
Epi means upon.
Epidermis, upon the dermis
when we get to the skin.
Epicondyle, this smooth
rounded surface here.
These are condyles.
They have specific
names, but I'm not
giving you all names now.
You'll get those later.
But these are epicondyles.
The lateral epicondyle
is perhaps better known,
because when you get
inflammation of a muscle,
it hurts terribly,
that attaches here.
What do they call
that condition?
Tennis elbow.
Any of you play tennis,
get sore elbows?
Yes, I've had them, too.
Right there, it's inflammation
on the lateral epicondyle
of the muscle.
Here will give us tennis elbow.
Then we move down to our--
Oh, I don't want that eraser.
Our forearm, where
we had two bones.
We had the radius, laterally
and the ulna, medially.
What are some
characteristics here?
On the distal end, we have
the head of the radius.
You can see the head here.
It allows for rotation.
We're going to talk about
supination and pronation.
There's the head of the radius.
We then have a radial
tuberosity just below it.
And the biceps will insert here.
The distal part of the ulna
has two characteristics here.
One is called the
olecranon process.
You can feel it when
you bend your elbow,
it's that pointed portion there.
Have you ever been
jabbed by somebody
with your olecranon process?
That hurts, right?
Giving you ideas,
but there it is.
You can see it.
You can see very
clearly in your book
to see how clear the
olecranon process is.
And from an anterior
view, it will have--
Anteriorly you'll see
the semilunar notch.
What does that mean?
Semi lunar, half moon.
Maybe if I get a
separate one because you
can see it more clearly.
OK what bone is it?
Femur, good.
It's not the one we
want, but is it femur?
No it's not, what is it?
Pardon?
You don't know it yet.
Here's a very nice humerus.
See the rounded head?
See the large greater tubercle?
What we're after is
something I don't see.
Here it is.
No, what bone is that?
I just gave it to you.
Radius, see that rounded head.
See the tubercle
there for the biceps?
I don't know,
where's their ulna?
There's an ulna.
Can you see that big notch?
That's your semilunar
notch that you
see right at your elbow to allow
it to function the way it does.
So you have a semilunar notch,
olecranon process, and then
proximally--
Wait a second, this is wrong.
This is proximal.
Sorry, this is distal.
Too much to give today.
So distal will have
the styloid process.
Fortunately, we have a
styloid process on the unla,
too, so that makes
it easy for you.
And this then brings
us to our wrist bones.
And the wrist bones
are the carpal bones.
We have eight of
them, carpal bones.
So there are two rows
of four bones each.
And you'll get those in
your advanced anatomy.
I'm not going to take
the time for them,
but you can see them
very clearly here.
Little bones down
here at the wrist.
And then your
metacarpals, of which
you have five, which
are your palm bones.
Metacarpals, are the palm,
and they're five of them.
And the head of the metacarpals,
what do they make up?
What do you see?
The knuckles, right.
The heads to the metacarpals
bowl equal your knuckles.
Funny word, what does it mean?
And then you have the
phalanges, which are fingers.
How many phalanges
in your fingers?
Three.
In your thumb, how many?
Two.
All right, that will
bring us down now so we
can start our pelvic girdle.
And we've said that,
what does pelvis mean?
Pelvis means basin.
Would you like to have a
basin that looked like that?
It'd be pretty
faulty, wouldn't it?
But that's where
the name came from.
Pelvis equals Basin.
Three bones, the ilium, the
ischium, and the pubic bone.
These three all come
together in one part.
I'm going to use--
to find one here.
Here's the part.
All three-- ilium,
ischium, and pubic bone--
come together in what's
called the acetabulum.
What does acetabulum mean?
What's acetic acid?
Vinegar, right.
So tabulum cup, vinegar cup.
Who knows?
[LAUGHTER]
But that's what it's called.
I mean you may be hard up,
and you're out for a picnic.
And you find a pelvis,
you have a cup, right.
[LAUGHTER]
I don't know.
Anyhow, so the three
all come together
in what's called an acetabulum.
So just remember acetic
acid, you've learned that.
And so it will receive,
what's it going to receive?
Here's your big femur,
fits right in there.
You watch those ballet dancers.
They have lots of--
It's amazing, though,
what it can do, isn't it?
But that's for the
head of the femur.
So receives head of femur.
All right, let's look at
individual characteristics
of each bone, so you
can have something
to identify each bone.
The ilium, we're going to
give the anterior iliac spine.
Here is my ilium and here's
the anterior iliac spine.
Anterior iliac spine.
We're going to see how important
it is when we attach ligaments
to it.
But at the moment,
it's a landmark.
Another landmark for
the ilium is the sacro--
here's your sacrum,
here's your ilium--
the sacroiliac joint.
Posteriorly, we
have the sacroiliac.
The anterior spine with
anterior, posterior,
the sacroiliac joint.
Why is it so important?
Well, it's taking all the
weight from the upper body,
transferring it down
to the pelvic girdle.
And this joint sometimes
loosens with aging.
Back pain when this
starts to loosen,
so you need to exercise
for your full lifetime
to keep all your joints strong.
So let's look then
at our ischium.
What's landmark for our
ischium, or a characteristic?
The ischium is
posterior and inferior.
Posterior and inferior.
I've mentioned them before,
these great big strong bone
projections here.
These are the
ischial tuberosities.
you are sitting on your
ischial tuberosities.
You can put your hand
on your buttocks,
if you slide it under.
It's OK, this is anatomy.
[LAUGHTER] You can
put your hand through,
and you'll feel
how sharp they are.
Try it.
Sure, some of you are daring.
Feel in there?
Have you ever known how
sharp they are back there?
They're pretty
pronounced, aren't they?
Those are your
ischial tuberosities.
All right, so what else do
we have with the ischium?
The ischium also
has a huge foramen.
See that big hole?
There's our acetabulum It's
called the obturator foramen.
So it has ischial tuberosities
and the obturator foramen.
So it's a large one.
Part of the foramen is covered
with connective tissue.
You have the foramen
to lighten the pelvis.
The part covered with
CT, connective tissue.
The open part receives
blood vessels and nerves.
So open part, blood
vessels, and nerves.
So we need that to
get the vessels down
to the lower extremity.
Then we have the pubic bone.
The pubic bone will be most
anterior of our pelvic bones.
Pubic bone.
And again, there
are two of them.
And they meet in the mid-line.
There's the pubic bone.
Meets in the mid-line in what's
called a pubic symphysis.
It's a joint, mid-line
pubic symphysis.
What does symphysis mean?
Together.
What kind of cartilage
are we going to have here?
What kind of
cartilage did we have
in the intervertebral disc?
Fibrocartilage, good for you.
Because they're strong.
You need a strong
cartilage between the bones
here, fibrocartilage
in the pubic symphysis.
And this joint, you
can appreciate why,
I loosens during childbirth.
During childbirth.
So there are differences
between the male and female
pelvic cavities, as
you can appreciate.
So sex differences
in the pelvis We'll
just give the male because
the female's opposite, then.
Which have we got here?
It could be either.
[LAUGHTER] Sort of in between.
The male obviously
is narrower, right.
He's narrower.
The pelvis is heavier.
Males on average weigh
more than females, heavier.
And what else are
we going to find?
It's deeper.
She has a shallow one, want
to get through there fast.
This is deeper.
So these are basic, very
fundamental characteristics
of your pelvic cavity.
Now we go on down to
the lower extremity.
We've already talked about
the largest and heaviest bone
in your body.
Largest, heaviest equals what?
Femur.
Good for you.
Thank you for responding.
So we'll see that
medially, it has
a head that has a neck that
has a greater trochanter.
And medially, it will have
a little, lesser trochanter.
These are just areas
where muscles attach.
We will be having muscles
coming in on these trochanters,
just like we have muscles
coming into our tubercles
on our upper extremity.
And we can tell whether they're
greatly athletic individuals
sometimes by the
comparative size.
Pretty good.
That's a pretty good
greater trochanter.
Pretty active individual.
Let's see what this one has.
Yeah, a big one.
This is a heavy ball.
This was a big person.
These are real bones.
Some of the bones you
have in lab are plastic,
but these are real.
So we can see very
clearly on this,
there's the head, the
neck, the great trochanter,
and the lesser trochanter.
Now, what's important
to know about this,
what area do you think would
be most frequently fractured
in your femur?
The neck, sure.
It's at an angle there, it's
going to get the forces down.
This could be weight bearing
more, but not that neck.
So neck fractures most readily.
Has anybody broken
the neck of a femur?
If we had a population over 65
and asked-- oh, one person has.
How'd you do it.
Back flip, on the hard surface,
not on the diving board?
You landed on the ground, huh?
That's unusual, though isn't it?
[LAUGHTER]
More older people
break their neck
of their femur in parking
lots at night in the dark.
You know those obstacles
that are there that tell you
when to stop driving your car.
And they're walking across
the parking lot at night
and they trip on that.
Very common to crack the neck.
So always watch your step
at night in a parking lot.
Neck, common site of
fractures in older people.
Though, people are afraid,
because if you fracture
your bones when you're older
and you become inactive,
everything degenerates.
So you've got to learn
all about your body
to be able to keep it healthy
so it doesn't degenerate.
All right, with this
we'll come down.
We have a shaft.
And we'll have large condyles.
We'll have one and two.
One will be our
medial epicondyle.
And two will be a
lateral epicondyle.
And what do we have anteriorly
between the condyles?
What's protecting
this knee joint?
What's this?
The patella, your knee cap.
Put your leg out
in front of you.
Relax it and put your--
feel your patella.
You can do it when it's relaxed.
When it's tight, you
can't move it around you.
Feel it.
So in between the condyles,
you have the patella.
What is the patella?
It's known as a sesamoid bone.
What does sesamoid mean?
Sometimes we have them
and sometimes we don't.
Do we have a sesamoid bone.
Yes, we do, terrific.
So it's a sesamoid bone.
And sesamoid means
seed, like a seed to--
I don't know what kind of fruit
would have a seed that large.
Avocado, who knows?
[LAUGHTER]
The sesamoid bone has
the characteristic
of being found in a tendon.
Most of your bones
aren't in a tendon.
A sesamoid bone is.
What's the tendon that the
sesamoid bone, the patella,
is found in?
What's the big muscle in
the front of your leg?
Your quads.
You have your quadriceps
femoris coming down.
They come into a
tendon, which is
going to insert on your tibia.
But before it
inserts, it houses--
I can't do this
with chalky hands--
It houses a sesamoid bone.
So this one in the
knee, sesamoid bone.
Thank you, I'll catch that.
Housed in tendon of quadriceps.
See, four-headed, quadriceps.
You have biceps, two heads.
Triceps, three heads.
Here's quadriceps in
your anterior thigh,
quadriceps femoris.
So having this tendon
here gives strength
as it comes from
this massive muscle
to insert down
here on the tibia.
And it will stabilize the joint
and protect the knee joint.
All right well, we'll show
slides and then go on.
But we covered a lot.
But again, you
review it each time.
Every time we bring something
in, we bring blood vessels in,
we review it.
We've taught muscles,
we review it.
But I have a brand new
slide to show you today,
and I can hardly wait
to show it to you.
When I saw this
picture I said I have
to have it for my 131 class.
So I want to be sure you see it.
Can we have the
lights quite far out,
please, so we can
give it its full view?
And we need to
focus a bit, please.
There, that's about
as good as it comes.
But have you ever see a
skeleton in these positions?
I just think it's dynamic.
Why, for hundreds
of years, do we just
show a skeleton standing there?
[LAUGHTER] Look at them,
isn't that dynamic?
Isn't that beautiful?
This is what we just reviewed.
Our manubrium, our body, our
xiphoid, our costal cartilages,
our clavicle.
our humerus, our
radius, and ulna.
Here's our pelvis, femur,
here's our patella.
Isn't this wonderful?
But it's a nice
way to study when
you can see them like this.
And the next one.
And here we are
with the menubrium
with the first costal cartilage.
Here's our sternal angle,
second costal cartilage, third,
fourth, fifth, sixth,
seventh, and then
the eighth through
tenth coming up,
and the 11th and 12th
big floating ribs.
Here's the xiphoid process.
Next one.
And this is our scapula.
Here's the spine.
Here's the acromion.
The supraspinous fossa,
the infraspinous fossa,
the coracoid process.
Here it is here on
this anterior view.
The glenoid cavity here for
the head of the humerus.
Next one.
Then we see it again, a good
picture of the glenoid cavity,
coracoid process here,
acromial process.
Here is our clavicle.
This will be medial.
It's convex, concave, lateral.
Next one.
And here's the head
of the humerus.
Here's the greater tubercle.
If we turn it over, we have
the head and a lesser tubercle.
The important structure
I should have mentioned,
but we'll catch it later,
the intertubercular groove.
We're going to have
major muscles attached
to that intertubercular groove
between the two tubercles.
And the next one.
And this just
shows that you have
this sort of stylized
processes at each distal end
of the forearm.
But here's the
head of the radius.
Our tubercle, or
olecranon notch--
or excuse me, semilunar
notch and our olecranon.
But you see the semilunar
notch from anterior,
you can't tell
that it's a notch.
You have to look
at it laterally.
But the head of the
radius fits right in there
so it could rotate.
We'll see that when
it does this motion.
Next one.
And this seems what happens.
It's a radiograph showing
fractures of the ulna
and the radius of a
10-year-old child.
Notice the distal
epiphyseal plates
of the ulna and the radius.
So you have your
ulna and your radius.
Look at the epiphyseal
plate, here.
You say, what in the
world does that mean?
[COUGHING] Excuse me.
[COUGHING] Get chalk in there.
[COUGHING] At least
At least it waited till
the end of the lecture.
Sorry about that.
The epiphyseal plate is
where your long bones grow.
We're going to talk
about bone development.
So when you look at a skeleton
and you see these plates,
you know this individual
has to be less than 21.
You lose all your epiphyseal
discs by 21, on the average.
All right, so that's
that for today.
