going to look at the rotation of the stomach
and its consequences for the dorsal mesentery
and the development of the spleen.
In this view, we can see the dorsal mesentery suspending
the gut and the ventral mesentery attaching
it to the body wall. I’ve sketched in the
greater curvature of the stomach in this view.
We can now also see the spleen developing
in the dorsal mesentery. As the stomach rotates
through 90 degrees clockwise as seen from
above, this dorsal mesentery is thrown over
to the side. We can see the spleen has shifted
markedly to the left hand side of the body.
In this position, it will attach to the back
of the abdominal cavity and adhere there.
What will happen next is the stomach will
rotate again, but in this case, so as it comes
to lie transversally across the body axis
with the gut entering from the left and exiting
on the right you will note that the greater
curvature now comes to lie downwards pointing
towards the feet. You can also see that this
has enclosed a space, and the space inside
behind the stomach is known as the lesser sac
of the peritoneum. The part which is hanging
down in front is reminiscent of an apron and
will cover the remainder of the gut. And from
that, is known by the Latin word for apron,
the omentum. So together, that forms the omental
bursa and space behind and inside it is the
lesser sac of the peritoneum. The spleen remains
attached to the inside of the abdominal cavity
further up but on the left-hand side.