00:01
So now let's have a look at the actual
stomach itself. We've concentrated on the
esophagus, so now let's have a look at the
stomach. The stomach is a strange-looking
organ. It's very much like a bag which is
being filled with food that's passing down
from the esophagus and you can see actually
the bit that's projecting above the esophagus
is known as the fundus. This is often filled
with air. And then the region immediately at
the entrance of the esophagus is the cardia
region, which you can see there. Here, we
then have the main substantial part of the
stomach which is the body. We then have an
indentation and a region known as the lesser
curvature. This is known as the angular
incisure. And that separates the body from
the pyloric antrum, which you can see there.
00:45
The pyloric antrum then tapers into the
pyloric canal which will eventually go on to
form the duodenum.
00:50
So there are some K-line marks there on this
anterior surface of the stomach. We also have
this short edge of the stomach which is going
from the esophagus all the way through to the
pyloric region. That's the lesser curvature.
And then we have a much greater curvature,
which is taking this longer course around
this perimeter aspect of the stomach. You can
see that on the greater curvature there.
Here, we can see the indentation between the
esophagus and the fundus of the stomach
around the greater curvature where it starts
and that is known as the cardiac notch. If we
were to look at the anterior surface of the
stomach, there's a slightly different tilt on
here. We can actually see here is the
anterior surface, that it has some
relationships with various organs and other
structures in the region. So here on the
lateral aspect of the stomach we can see
where it comes into contact with the
diaphragm. Here is where the left lobe of the
liver touches on to its more medial surface.
01:47
And here we can see it has a connection with
the anterior abdominal wall. So the stomach
is quite superficial and it's touching the
anterior surface of the abdomen. It's also
touching the diaphragm and it has a
connection with the left lobe of the liver.
02:01
If we were to spin the stomach right to look
at its posterior surface, then actually its
contact with lots of other organs as well.
We'll come to how it's related to the
transverse colon in a moment. The transverse
colon is part of the large intestine. We can
see that's associated with the greater
curvature of the stomach. It's associated
with the spleen and important blood vessel
runs along the posterior stomach body. This
also supplies the spleen, the splenic artery.
We also have the pancreas that runs alongside
it as well. We have various kidneys, adrenal
gland, all associates it with the stomach
posterior aspect. So the fact that you've got
lots of these structures sitting and touching
its posterior surface does let you know that
the stomach is relatively anterior within the
abdomen. And by moving the stomach away,
lifting the stomach up, moving it to the
side, you will reveal structures that lie
underneath. So let's have a look at the
surface of the stomach. The inner surface of
the stomach is highly rough.
03:01
It's got lots and lots of elevations, there's
lots of contours within the inner surface of
the stomach and that helps it to expand and
change in size as we ingest food. It also
helps to increase the surface area which is
important. But what we can see if we go back
to that region where the esophagus joined the
stomach.
03:20
We can see we have this cardiac orifice.
This opening between the esophagus and the
stomach. And here we have a Z line and that
really demarcates some histological
differences between the esophagus and the
stomach as a whole. So we can see the
esophagus is now entering into the stomach.
03:39
Again, looking at the stomach, you can see
its wall, we've got these gastric folds or
rugae. And these are those undulations giving
increased surface area to the stomach helping
it to expand with size but also increasing
its surface area. As we have a look at the
outer wall and various aspects of the stomach,
you can see just running along the lesser
curvature we have these longitudinal folds of
gastric canals and they help to channel food
down towards the pylorus. So once the stomach
is churned, they help food to pass in the
right direction down to the pylorus. Here,
we're specifically looking at the pyloric
sphincter. So this is the very end of the
stomach. So food is entered, chew in,
esophagus, is passed into the stomach whereas
digestive processes have occurred and then
the food is channelled all the way down to
this pyloric sphincter. Now this is a very
hot anatomical sphincter. It has
specializations of circular muscle, meaning
is under constant control and regulation. So
where food can naturally flow from the
esophagus into the stomach, there's more of a
physiological sphincter. Here, guarding the
stomach from the duodenum we have a pyloric
sphincter and that has clearly lots of
circular muscle that helps to regulate the
flow of food from the stomach into the duodenum.