And then finally, the finally organ
I want to concentrate on, is the rectum.
Because this has quite a substantial blood
supply coming from multiple sources.
We can remember once again that the rectum
is going to be supplied by branches
from the inferior mesenteric
artery, from the internal iliac.
and that's we will explore when we look at the
perineum branches from the internal pudendal artery.
What we have got here is the posterior view of the
rectum, posterior view and here we have got our
ischial tuberosities, we can see here
moving up towards the ischiopubic rami.
moving up towards the pubic symphysis.
We can see we have got the sigmoid colon
here and we can see its bending
down to form the rectum.
And what we can see coming from the aorta just before
it bifurcates, is the inferior mesenteric artery.
The last branch really to come from the inferior
mesenteric artery, the one that kind of runs
closes down in the midline
is this one here and that is
your superior rectal artery.
We can see the superior rectal artery dividing, remember
it?s an unpaired branch, this superior rectum, it has one of them.
But it does divide, it bifurcates into lateral
branches that run down the lateral surface
of the rectum. We can then
see here, if we pick up the
internal iliac which we can see here,.
the external iliac is going forwards.
The internal iliac, we can see here, gives rise to the
obturator artery passing through the obturator canal
and it gives rise here to the...
gives rise to the internal pudendal
which we can see running down here.
That as we will come to recognize gives the series
of branches that supply the anal canal region.
But what we were concentration on is
the potential for these 60% of the people
to have this middle rectal that's
going to pass down in this direction.
You can see that there is lot of
connections between the middle rectal
and the superior rectal. And this
is supplying the superior, middle
and potentially the lower
portions of the rectum.
But within the anal canal which
we will look at in the perineum
around here, we can see that's actually supplied by
a branch coming from the internal pudendal.
But the rectum up here is supplied by superior
rectal and if present, the middle rectal.
So this will just include some of the notes of what I
have just described. You have three parts of the rectum.
This proximal part, middle
and inferior part,
all carried out by branches from the inferior
mesenteric or the internal iliac artery.
And this is anorectal junction, this division here.
Here we can see the pelvic floor
which we will look out in the next
lecture. And everything inferior
superficial to the pelvic floor is going to be
supplied by this inferior rectal artery.
which comes from the internal pudendal. And I think that's a
good place to leave it because we will look at that
in lectures to come.