let's think about the blood supply to
and from the kidney there's a very
intricate arrangement of arterial and
venous vessels within the kidney forming
really quite a beautiful intricate and
somewhat complexed vasculature but if we
think about it in simple terms it's got
some fairly basic components so let's
think first of all about a kidney so
here we have a kidney let's say that's
the the right kidney and we have the
structure of the kidney round there and
the hilum which is the entrance where
things get into and out of the kidney
and you probably know that the renal
parenchyma consists of the renal cortex
and the renal medulla
pyramids so here we have a medullary
pyramid with a base and an apex you
maybe got eight nine ten of these in
your kidneys just draw a few today to
keep it simple so these are the renal
medulla and pyramids round about the
outside is the renal cortex the renal
caption on the outside of that's of
course and these are the cortical
columns projecting down between the
individual renal pyramids now then we
have the aorta carrying blood down from
the left ventricle so as we know the a
or two originates in the left ventricle
arches round you have the thoracic aorta
goes through the diaphragm into the
abdominal aorta and here we have the
abdominal aorta there's a branch going
to the left kidney that will be the left
renal artery
and here we have a branch go to the
kidney I'm thinking about now go to the
right kidney and of course the air you
want to carries on further down to
supply the lower half of the body so we
have a renal artery entering through the
hilum of the kidney
now the kidney is essentially hollow in
a sense because it contains the renal
sinus so here we have the renal sinus
then the renal sinus is this hollowed
out area in the middle of the kidney and
it's through the renal sinus that the
arteries pass and the veins pass
carrying blood in the opposite direction
and also those lymphatic vessels and
nervous vessels in the renal sinus and
of course the calluses and the renal
pelvis are also located in this area and
any spare space in there is filled up
with protective and in first issue now
the renal artery divides into segmental
arteries so here we up some segmental
arteries carrying blood off to segments
of the kidney and then the segmental
artery will divide and smaller arteries
will carry the blood through the
individual renal columns the cortical
colonists and these are the inter Loba
artemis so one lobe of the kidney will
be like one section like this that would
be one lobe that would be another loan
so a lobe is one renal pyramid and the
cortex a book that we know pyramid so
these are inter Bomba
artists can be blown up that way now
the interloper artists go up the green
or column and then they Bend sideways
and they go along like this and these
arteries that go along the basis are
called the arcuate arteries the arcuate
because the kind of arc over the top of
one of the bases like this the arcuate
artists it actually derives from a word
which means bowgasm bow in arrow they
are they are arcuate so we have the
inter lobo arteries turning into the
arcuate arteries now from the arcuate
arteries numerous slaughter arteries are
going to branch of the way like this
it's going to be the same all the
arcuate arteries so they're going to be
small arterial vessels branch off the
arcuate arteries and these are called
the internal mobula arteries so this was
the interloper artery
and these are into lobular artemis
obviously much smaller now from the
inter lobular arteries numerous
individual arterioles branch off and
these are the efferent arterioles so the
afferent arterioles are branching off
the intima Beulah arteries and of course
the afferent arterioles take blood into
the individual renal corpuscles
you might have half a million individual
renal corpuscles you might have a
million and a half some people even have
two million or slightly more the average
is about 1 million per kidney and these
are supplied with blood by the
individual afterwards arterioles the
afferent arterioles now the athlete
arterioles pass into the glomerulus the
Camela light the kidney and from the
Gamaliel Asst the blood drains into
efferent arterioles and the efferent
arterioles themselves break up into
smaller capillaries and the capillaries
in the cortex surrounding the upper part
of the renal tubules we can't see it
here because they're microscopic these
are the peritubular capillaries so there
are peritubular capillaries and in the
medulla the efferent arterioles break up
and branch into the Bastyr rector blood
supply and blood drainage system so the
vast erector are going to draw the
venous system on the lower the W pyramid
so we don't get to cluttered up so the
bus director are going to be coming up
here and they're going to form larger
venous vessels like this
so these are the bass director capillary
systems and small venules leaving the
renal medulla to Pyramus and the
situation is similar the in the cortex
here the peritubular capillaries drain
into in somewhat below Venice
so the peritubular pillar is their
venous blood is going to go into these
intima Beulah vents so we see here that
good is coming back up from the medulla
and back down from the cortex and in the
same way there are arcuate arteries over
the basis of the pyramid in the same way
there are arcuate veins so these all
drain into arcuate parents I was a
little misshapen but I think you get the
idea
the arcuate vein arching around the base
of the medullary pyramid and in the same
way this bends around the corner and the
blood goes back in a vein here the
interloper they've and there be another
interloper vein coming from this one as
well
and then the interloper veins are going
to go back into the renal sinus and
they're going to join together into
segmental veins
now it's interesting a lot of the
Nathalie books don't mention segmental
veins but they have to exist to get the
blood from the interloper veins back
into the larger renal babe so here we
have the segmental veins draining blood
back into the larger single renal vein
and of course the renal veins drain
blood back directly into the inferior
vena cava so here we have the inferior
vena cava and as you know that's towards
the right side of the body PA water is
on the left there's another branch here
going to the other near the vein near
the renal very much would be under that
go too near the kidney so we see that
the blood is entering via the aorta
going through the renal artery from the
renal artery it's going up the renal
columns in the interloper artery into
the acute artery from the acute it's
going into the inter mobula artery into
the efferent arterioles through the
glomerulus into the efferent arterioles
into the peritubular and vastus rector
capillaries from here the vastus rector
are draining up the
in some Bob Vila veins are draining down
taking the blood back into the accurate
vein taking blood back to the segmental
vein back to the renal vein where it's
going to start its journey back to the
right atrium so the blood supply through
the kidney and it's interesting to note
that even though the kidneys are only
nought point five percent of body mass
20 to 25 percent of cardiac output is
going to the kidneys they are remarkably
vascular organs and this is very
important if they're traumatized because
there can be to rental hemorrhage as a
result of renal Troy because it's a very
vascular but in health
lots of arterial blood needs to go
through it because of course the kidney
is filtering this blood removing
impurities homeostatic lis regulating
the constituents of the blood and
returning it to the venous system
you