Okay, let's explore the lesser
sac in a little bit more detail.
Here we can see the liver
and we can see the stomach
and we can see the membrane between the
liver and the stomach: the lesser omentum.
So here we can see the
lesser omentum running here.
Remember the lesser
omentum, its free edge
epiploic foramen allowing
the greater sac and the
lesser sac to communicate.
If we were to look at the boundaries of the
lesser sac then to do that we have opened up
this lesser omentum here. And we can see posteriorly
we have this organ which is the pancreas.
Now if you are standing on the
pancreas and you are looking forwards
the anterior boundary is going to be
the stomach in the lesser omentum, obviously.
You have got the pancreas behind you
You have got the stomach in front of you. So
the anterior and posterior boundaries are those two.
Laterally, so over in this direction
we have got the spleen.
In the lesser sac here now with
the stomach being lifted up.
So anteriorly it's being removed to see in
the lesser sac. Posteriorly got the pancreas.
Laterally, we have got the spleen
over here and medially
we have got the caudate lobe of the liver. And
these are the boundaries of the lesser sac.
Remember the lesser sac can communicate with
the greater via the epiploic foramen.
Let's concentrate on
the lesser omentum.
The lesser omentum this
double layer of peritoneum
extending from the lesser
curvature of the stomach.
to the liver. It also extends
from this first bit
of the first part of the
duodenum. So we can see
the lesser omentum extends the
lesser curvature of the stomach.
And the first bit, the
first of the duodenum
so it's extending here and its going to
the liver, and that's the lesser omentum.
Because it is coming from the stomach
and the duodenum to the liver
it's got two peritoneal
ligaments within it.
The lesser omentum can be divided
into two peritoneal ligaments.
The heptograstric ligament, liver
stomach connection so this be here.
This will be your
And the remaining part that is going from the
liver to the duodenum, so this portion here
is the hepatoduodenal ligament.
The hepatoduodenal ligament is
really important. It contains
what's known as the portal
triad. It's three structures.
Portal triad that pass
towards and from the liver.
It contains the
hepatic portal vein
taking venous blood from the
GI tract to the liver.
It contains the heptaic artery
providing the liver with oxygen
and nutrient rich blood for it to function.
It also contains the bile duct
which is bile produced in the liver;
the way for it to pass into the duodenum.
So it's three structures. Deep to it
this is the hepatoduodenal ligament
and then we can see the omental foramen again
this little aperture just underneath.
That communicate as I have said,
the lesser and greater sacs.
If you were to insert a finger in this
foramen then you would have four boundaries.
Your finger in this foramen, then posteriorly
it find your inferior vena cava.
Anteriorly, you would find your hepatoduodenal
ligament and the portal triad.
Superiorly you would have the
caudate lobe of your liver
and inferiorly you would have your
duodenum, the first part of the duodenum.
With your finger communicating between
the greater and the lesser sacs
they are the boundaries of the
epiploic or the omental foramen.