PROFESSOR: --in the stomach.
An example would be alcohol.
If you don't want it to be
absorbed, what do you do first?
Drink milk-- you know that.
What else?
Somebody else said something.
Eat meat-- Did I hear that?
I don't know.
But, if you're going to
drink milk to prevent this,
be sure that it has fat in it,
because that's the reason you
take milk, right--
so you can't absorb.
Now, some drugs, very few drugs
are absorbed in the stomach.
What's the common one?
STUDENT: Aspirin.
Aspirin-- right.
So, a drug--
But you do wonder--
sometimes they
tell you to take your
aspirin with a beverage.
Would you take it with fat milk?
No-- but basics to learn.
So that gives you an idea of
why you have your stomach.
So, let's go on to
our small intestine.
And the small intestine
will extend in
from our pyloric sphincter.
At what vertebral level
is our pyloric sphincter?
It will begin with
our pyloric sphincter.
At-- is it T1 or 2--
we'll put T1 and check it--
and will end at the
ileocecal valve--
ileocecal valve.
How long is that?
About 20 feet.
Have you ever seen your small
intestine stretched out?
STUDENT: Not mine.
PROFESSOR: Pardon.
STUDENT: Not mine.
PROFESSOR: Not yours.
I need two people.
It took us a while to
get this small intestine.
Somebody-- two-- Thanks.
I know you'll cooperate.
All you do is go
across the stage
and take out your
small intestine.
Isn't that amazing that all of
that is twisted to fit in here.
Oh, I used to do that.
We called it--
[LAUGHTER]
Should we do it and
to fall on the stairs?
That would be dramatic.
That's a first.
We do this each year to show--
just so you can get an idea
of how long your intestine is.
OK-- We can rock it up.
Thanks ever so much.
[APPLAUSE]
PROFESSOR: Yeah, they get a hand
for that because that was nice.
We'll try jump roping some
other time when we don't
have stairs in front of us.
Thank you.
All right-- This small
intestine then is divided.
It has three divisions that
carry on different functions.
First one is the duodenum.
What does duodenum mean?
It means 12 fingers.
You put 12 fingers side by
side and you have 10 inches.
So, it means 12 fingers
to equal 10 inches.
And then we have the jejunum--
jejunum-- And the
jejunum means what?
You'll never guess--
empty at death--
And it'll be about eight feet.
And the third part is what?
The ileum-- you spell
it with an e or i?
STUDENT: [INAUDIBLE]
PROFESSOR: An e, right.
Ileum--
I didn't say begin with an i.
It's the e here,
because with your--
[LAUGHTER]
All right-- The ileum--
This is really strange.
I don't make up these
words, but it means groin--
essentially the same that
the other ilium means.
So this means groin,
and what has it got?
It's got about 10 feet, so
it gives us roughly 20 feet.
These are the
figures that you get.
So different things are
occurring in different parts.
Let's look at the
small intestine
then and see how it's built
to carry out its functions.
So, we'll have the mucosa--
--is thrown into folds.
And on it we will have
finger-like projections,
increasing surface area
tremendously here--
--and so forth.
And these projections are
the villi, collectively--
singularly, villus.
And they will have
what used to be called,
with the light microscope,
a striated border
on their surface.
Just do a little
striated border here.
Which are really what the
electron microscope turned out
to be microvilli,
increasing the surface area
more with an EM for
electron microscopy--
These will microvilli.
And to show one important
function related to them,
they're filled with
acid phosphatase--
have acid phosphatase--
--and that will then enhance
the absorption of calcium.
We'll just put aids absorption
of the calcium ion, so
a very important ingredient.
Now, with these
villi at the base,
we have what are called
the crypts of Lieberkuhn.
Crypts of Lieberkuhn
are down at the base.
And why is it important
to know these?
Their cell is called
the cells of Paneth
in the crypts of Lieberkuhn--
has cells of Paneth.
And the cells of
Paneth, then, have
enzymes for the digestion
of carbohydrate enzymes
for carbohydrate, fat,
and protein digestion.
What else is important about
the crypts of Lieberkuhn?
Colon That the cells that line
the villi are being produced
at the crypts of Lieberkuhn--
sort of like a conveyor belt
being produced in the crypts--
produced in the crypts.
And they're produced at the rate
of about three or four days.
They are renewed.
Why do some of us like this?
Because sometimes people
say, well, how old are you?
I say parts of me are
only four days old,
and that's true, right?
And doesn't that
feel good, right?
[LAUGHTER]
Anyhow, we can have lots
of fun with the body
when you have the facts,
and that's a fact.
So what else do we have here?
In our duodenum, we
will have glands,
and the glands are called what?
Brunner's glands.
And what's the purpose
of pruners glands?
We've just put in
all of this acid
into the duodenum
with a pH of 1.
We've got to neutralize that.
So right in the duodenum,
you have Brunner's glands
to neutralize
the HCl and give us a
pH then of about 7.6--
--so very important.
And that's one way when
you're having your examination
and you have a piece of tissue
from the small intestine,
just look for Brunner's
glands and you
know what part you're in.
So, another part of
the small intestine,
which has a very
characteristic--
is the ileum-- and it will
have masses of lymphocytes.
We've learned this before.
What are they called?
STUDENT: Peyer's patches.
PROFESSOR: Peyer's patches.
These are Peyer's patches.
We've mentioned them previously.
And they are there to fight
any bacteria that is coming in.
I'll just put fight bacteria.
And that tells us a
little about the structure
of the small intestine.
We'll see if there are other
things that we should mention--
no, that's essentially--
But I did want to share
something, because
I went to the web this morning
to find out a little bit more
about the GI, excuse
me, the GI tract.
And it says that
the HCl releases
vitamin B12 from the food.
I've never heard that
before, have you?
And then it said--
you know where
it's being absorbed--
most of the absorption
in the small
intestine takes place
in the duodenum and jejunum.
So, we'll put that
down, because that's
a fact in all your textbooks--
most absorption in
duodenum and jejunum--
but with this HCl releases
vitamin B12 from food,
and it's absorbed in the ileum--
just to show we don't
really know everything
there is to know
about the GI tract,
even though there's lots
that's conventional.
So, we'll put absorbed
in ileum.
I mean we can look up
new facts all the time,
but you won't get your basics.
And so I try to
stay to your basics.
So be sure you have those well,
and you'll be building on them.
And what happens when you
don't have vitamin B12?
You become anemic and fatigued.
You feel-- a lot of you
have B12 deficiency now.
So, lack of B12--
anemic
and fatigue-- But it
is rare, because b-12
is found in eggs and milk
and many of the common foods
that we should be
eating every day.
But I thought the fact that it
was being absorbed in the ileum
was just of interest, possibly.
Now, let's move on to
the large intestine.
Why is it called
large intestine?
Just seeing we don't have
room for another intestine
as long as our small intestine.
It's large in contrast
to small in diameter--
larger than small
intestine in diameter.
So how long is it?
It's only about 4
and 1/2 feet long.
Now, what can we say
about the large intestine?
It has several parts.
First, we'll just list them--
the cecum, the colon,
and it's the colon
that has its various parts.
It has the ascending part,
the descending part, and--
no, we've got to put a
transverse part in first--
a transverse, then a
descending, and, then,
what's the last part?
Sigmoid
Where did we have a
sigmoid structure before?
STUDENT: [INAUDIBLE]
PROFESSOR: Pardon.
The venous sinuses
in the skull, right?
Remember those?
A sigmoid sinus.
Here, we've got a sigmoid
colon, so it's s-shaped.
That's all it's telling us.
So, the cecum will
be a blind pouch.
And it begins in the right
lower abdominal quadrant.
So let's just pretend this
is our abdominal wall divided
in quadrants.
We're going to start over
here with this blind pouch.
And we have the small
intestine coming in here.
So what did we call the valve?
What do we call this valve?
Ileocecal valve.
And this blind
pouch is my cecum.
It's wall, like the ilium, is
also filled with lymphocytes--
many lymphocytes.
And it has a small
structure coming off it.
And we call that
small structure what?
STUDENT: Appendix.
PROFESSOR: The appendix.
Have you had your appendix out?
How many have had
your appendix out?
Not many.
In our day, whenever
you got any sort of pain
in this right lower quadrant,
they take out your appendix.
But it's like the tonsils--
It's filled with
lymphocytes again.
It has functions.
But if I can't fight them--
So we see the little
appendix there in the--
How do you tell
somebody exactly where
the appendix is if it's in its
normal position from surface
anatomy?
So, from surface
anatomy, you find
your anterior iliac spine--
anterior iliac spine--
and you draw a line over
to your umbilicus--
Just have it here--
and a third the
way along you have
a point, McBurney's point--
McBurney's point.
So you figure out where it is--
go deep, and that's
where your appendix is.
I'm going to backtrack just
a little minute to cover--
I didn't know where to
put it in-- but we've
got to discuss the peritoneum.
And then I'll come back to
the appendix, because we'll
say what happens if the
appendix bursts and puts
all the contents
from the cecum out
into your peritoneal cavity.
So let's go to the word
peritoneum for a moment
and then come back
to our GI tract.
We've had
the pericardial sac with
parietal and visceral
pericardium.
We've had the pleural sac in
the thoracic cavity, the pleura,
with parietal and
visceral pleura--
and now we have the peritoneum
for our abdominal wall
and viscera.
So, the abdominal wall, what
are you going to line it with?
You're young anatomists,
you've got to give it a name.
What are you going to
name the peritoneum lining
the abdominal cavity?
Can't hear you.
STUDENT: Parietal.
PROFESSOR: Parietal--
parietal peritoneum--
right.
So the abdominal wall is lined
with parietal peritoneum.
And the organs, the viscera,
are covered with what?
Visceral peritoneum.
So what do we call the
space between the two?
STUDENT: [INAUDIBLE] cavity.
PROFESSOR: Peritoneal cavity.
So, in here, we have
the peritoneal cavity.
So, obviously, you
don't see much of it
because the organs are
all piled on each other,
but it does exist.
The simplest way to do this
very, very simple cartoon
is to make this our
abdominal cavity.
And we've got the abdominal
viscera going through it,
in just this form,
and we'll find then
that the parietal peritoneum--
I'm going to get
different colored chalk--
would be lining the cavity.
That's our parietal--
and the visceral,
we'll just leave as
green, because that's
lining the viscera.
But the point is
that I've just done
this in very
cartoonish fashion--
because when you've got 20
feet, this whole thing is
wound in here, and you certainly
don't have a cavity like this.
But I wanted you to
see, accentuated,
that it does exist so that,
if I get a burst appendix--
that can happen--
the contents can--
The contents go into
the peritoneal cavity.
And if it's not
treated immediately,
death can ensure, because
you've got feces then
in the peritoneal cavity--
an extreme case-- feces
in peritoneal cavity.
Sometimes you give
worse scenarios
because it makes it
dramatic to know that there
is a peritoneal
cavity, even though you
don't see it this way,
and this can be death.
Has anybody ever
had a burst appendix
or know anybody who did?
You did.
How long did you have it
before it was treated?
You don't know--
well, all right.
Well she's here, so it
didn't take too long, right?
[LAUGHTER]
Now, that gets us our cecum.
Let's follow our
ascending colon--
we'll take it up.
This now is ascending colon.
What we're essentially
doing with its path
is making a picture frame
around our abdominal wall.
And so we have the
ascending colon that'll
go into the transverse colon--
all continuous tube, just
different locations--
and then it will turn
and go descending.
And when it gets down to
about the crest of the ileum,
it will turn over and become
sigmoid to the midline--
it's got to reach the midline--
and then go into the
rectum and into the anus.
So we have ascending,
transverse, descending,
and sigmoid.
Just to give the
dynamics of them--
The sigmoid is coming right
below the stomach across.
And when we had one of
our guest speakers once,
he said a patient
that he saw had
the seat belt tight around the
waist when he had an accident--
and it just crushed that
whole transverse colon.
So, as an abdominal surgeon, he
just took out all the crushed,
and he just connected the
ascending to the descending.
A word about the sigmoid--
Feces are stored in
the sigmoid colon.
They're not stored
in the rectum--
feces stored in sigmoid colon.
You hear a lot about cancer
of the colon these days,
having colon cancer.
Which part do you think
cancer is most prevalent?
STUDENT: Sigmoid.
PROFESSOR: Sigmoid, right--
cancer most prevalent
in sigmoid.
All right-- What are its
functions, and then let's
look at its inner structure.
Why do we have a
large intestine?
Well, first, it
will be receiving
the undigested and
unabsorbed food--
receives undigested
and unabsorbed food.
And something that
you may not have known
is that here is where
water is absorbed.
