If we look at the segments of the kidneys, then this isn't
indicating the relations they have with other organs.
This is actually just indicating
the various segments.
And each kidney is divided into five
segments. So we have one here in blue
and then we have 2, 3, 4 and 5.
We can't see these both on
each side. But on anteriorly we
can see we have got 1 here
and then anterior superior and
anterior inferior segments here.
We can't see those on this one; because,
this is more posterior view.
And this posterior view let us see
the posterior segments which is here.
The both of the superior and inferior
segments are viewable on both this
anterior and posterior view anterior here. And
we can see the inferior segment here and here.
So these 5 segments are important; because, each
segment of the kidney is supplied by a specific
segmental artery. And these
are segmental end arteries
which means they don't
have any anastomoses.
Like the anastomoses we saw between
the left gastric, right gastric,
left gastroomental, right gasroomental
we don't have that here for the kidneys.
We have these end arteries. So one branch
of the renal artery will go and supply
its specific segment.
One of these 5 segments.
So let's carry on looking
at the kidney. And let's
just have a brief little look at its
some external features. Appreciate this
kidney has been sectioned. So
we can see into the hilum
But let's have a look at some of these external
features. We can see we have a superior pole up here
and we have inferior pole
down here. We have a nice
convex lateral surface around
here and we have an indented
kind of a concave medial surface
and this is the renal hilum.
This space here is the renal hilum. The
renal hilum marks the entrance to a space.
I have indicated earlier located within
the kidney and that is the renal sinus.
So this space here is the renal sinus.
We can see it's covered with
it's filled with fat. Also
running within the renal sinus
through the renal hilum are the
renal veins, the renal arteries
and the renal pelvis. We'll see the formation of the renal
pelvis which is continuous inferiorly with the ureter
we will see the renal pelvis
is formed via major and minor
calices. And these drain the renal
pyramids, we will speak about these later on.
Also passing through the renal
hilum within the renal sinus
are going to be various nerves that
control the activity of the kidneys.
So make sure we are happy with the superior pole
and inferior pole, a nice curved lateral convex
surface and an indented medial
surface which is the renal hilum.
Each of these minor calices are going
to be formed via the renal pyramid.
And we can see these renal
pyramids indicated here.
And renal pyramids are where
the nephrons are located.
They do this water exchange
that control the
water content that control the salt
content and produce urine within the kidney.
And they pass these,
this fluid passes
through what's know as the renal papilla
and it opens up into a minor calyx.
So each of these renal pyramids, which we
can see here, separated by a renal column.
The renal column being an extension of
the cortex in between the pyramids.
These will give rise to a minor
calyx and the minor calices
are going to form a major calyx. So here
we have a number of minor calices
forming a major calyx. And you
may have 2 or 3 minor calices
merging to form a major calyx.
And 2 or three major calices
forming the renal pelvis.
So here we can have a minor, minor, minor
forming this major one here.
There are few more minor ones, here and
here, and they going on to form another
major one here. And a few more majors
receiving the minor calices
here. And ultimately these are all
coming in to form the renal pelvis.
This dilated kind of triangular shaped arch
within the renal hilum passes through
the renal hilum and it is then
continuous with the ureter.
We can see in this case that we have
may be a couple of renal pelvis
that kind of split. And we can also see
we have kind of a large renal pelvis here
there hasn't been split and it's receiving
those minor and major calices.