You have got these
acid producing cells, these parietal cells
creating acid within the
lumen of the stomach. The problem is
that the acid could burn away
could destroy the mucosal lining
of stomach. And in the diagram
we can see what is a gastric ulcer,
an ulcer within the walls
of the stomach. So there is a balance
There is a balance to be had between the acid
in the lumen and the amount
of mucus that is produced. To
protect the lining of stomach
a carpet of alkaline mucus is
secreted by the epithelial
layer of the stomach.
So that produces mucus, that lines
the internal surface.
So the acidic lumen cannot
destroy/damage the internal surface.
So there is balance
which is depicted here.
Reduction in mucus production or
increase in the acid content of
the lumen can lead to
perforation of the walls of the stomach.
And that could be, particularly, nasty, can be
particularly, painful and
very serious. Perforation,
the content of the stomach can leak into the
peritoneal cavity leading to peritonitis
and infection. Haemorrhaging if the
perforation was to damage blood vessels
could lead to blood in your
stools or vomiting
out blood if you are to be sick.
Bleed into the gastrointestinal
tract and that is excreted, that is how
we get in our stools. Or
if the ulcer repairs and you have some
starving, this can cause a blockage.
And if the food can't progress down
the gastrointestinal tract
then that can lead to a
build up of food within the
stomach and you can have
the projectile vomiting. So with those
really important that we have this
acid production in the lumen. It’s also
important that we have this alkaline mucus
and we have this balance
to prevent the wall of the stomach
from being damaged.
Let's turn to
some of the gross anatomy,
the position of the stomach.
And here we can see really nicely
how the stomach is positioned in situ
how it's actually positioned if
you were to open up one's abdomen and view it.
The liver here is been uplifted here slightly.
But like I mentioned before we can see the lesser
curvature of the stomach here. We can see
the greater curvature of the stomach here
up here, we have got the
fundus, we have got the
body, we have got the
pylorus and we have got the
pyloric sphincter over here.
Remember me saying that the lesser
curvature was connected to the liver,
while here we have got an important membrane
that is connecting the stomach to the liver.
We will come across this in later lecture.
It's really important, it's the lesser
omentum, specifically the
hepatogastric ligament of the lesser omentum,
we will come to that later on.
So in this side of screen we can also
see the relations of other organs
to the stomach. So in this side,
we can see what is the anterior view
and here we can see the posterior view.
Now, you may not be
familiar with the position of these
organs, so it may not make a lot of sense
right now, but by the end
of the course we
spoke about these other
regions, these other organs
you will be able to imagine the
precise position of the stomach.
So we can see anteriorly and it's linked
very well to this diagram here.
We can see we have got a liver
here and so we can see the liver is having this
impression if the liver would float
down if haven't been elevated which we can
see in this diagram. It will be
lying over the stomach. Over here
we have got the diaphragm.
So in this anterior surface of the
stomach, we have got the diaphragm
which is coming down covering this region here.
So if you immediately open up the abdomen
in this region you will find the stomach.
And then down the bottom you just
have the other parts of the anterior abdominal wall
where the diaphragm is finished.
Importantly, though what does
the stomach sit on, what's
known as the stomach bag?
What lies immediately posterior
to the stomach?
So with this, we float the liver.
We float the...
stomach over, posteriorly we can
see we have relations to
spleen. So the stomach would be coming
in this kind of position here. So immediately
behind the stomach, we have the spleen,
we have the kidney, we have the pancreas
we can also see in this region
down here, we have the
transverse mesocolon. We will look on
the trasverse mesocolon in more detail
later on. So we can see
the position and relations
of the stomach to the
other abdominal organs.