hello everyone this is dr fox let's talk about the locations and positions
of the kidney in this video we'll discuss the location of the kidneys within the abdomen
and relate the basic superficial features of the kidney to their positions with respect
to the entirety of the urinary system there are paired kidneys within the retroperitoneal space
that are lying lateral to the spinal column and aorta and inferior vena cava these kidneys are
dynamic filters for the blood and any of the filtrate which becomes urine is then drained
through ureters that descend the abdomen and enter into the pelvis to drain into the urinary
bladder and that urinary bladder is then drained to the external environment by means of a urethra
the kidney itself has two borders and two poles uh laterally there are the convex
lateral borders and medially the borders are
convex superiorly and inferiorly and concave in a region known as the hilum the hilum is where the
neurovasculature and the renal pelvis which is the structure that drains the urine from the kidney
exists there are also superior and inferior poles the superior poles tend to be in association
with the supra renal glands or adrenal glands and the inferior poles tend to be
about two and a half to three and a half centimeters superior to the iliac crest
sometimes there are special types of accessory renal arteries which can be found
serving the regions of the poles that are called polar arteries so keep your eyes out for those
the hilum of the kidney a hilum is an area where neurovasculature enters and exits the hilum
of the kidney includes several major elements there's the renal artery and that renal artery
is going to divide into various segmental arteries within the the hilum there may also be accessory
renal arteries that serve the hilum are the renal vein within the hilum and the renal pelvis which
is contiguous with the ureter within the hilum of the kidney that hilum of the kidney if we move
more laterally is going to be continuous with a space called the renal sinus which
is surrounded by the parenchyma of the kidney as we'll see in terms of their relative positions
the left kidney tends to be a little higher than the right kidney although that's not evident in
in this particular photograph the left kidney tends to have its superior pull out at about the
t 11 vertebral level in its inferior pole down to the l2 level so t11 through l2 whereas the
right kidney tends to be a little lower and that's because we have a very large liver occupying that
right upper quadrant the superior pole of the right kidney tends to be at about the t12 level
and its inferior pole tends to be at the l3 level we say that the kidneys are within the
paravertebral gutter that's a difficult space to really appreciate looking at a frontal view but
when we see more of a transverse section this will become more evident to uh to really understand
that we need to understand that deep to these vessels here deep to this neurovasculature is the
vertebral column and so the kidneys are lateral to the vertebral column in this space that that
we call the pair of vertebral gutters the hilah of the kidneys are at approximately
the l1 level and that l1 level anatomically is oftentimes referred to as the trans pyloric
plane uh the transpyloric plane if you were to to think of this from superficial landmarks
if you were to go from the the sternal or the uh the jugular notch down to the pubic symphysis um
the the transpyloric plane would be approximately the midpoint of those those two palpable landmarks
it corresponds with where the stomach which i'm kind of crudely drawing in here where
the pyloric part of the stomach is going to feed into the duodenum of the of the small intestines
now the hila of the kidneys and this is an important thing to note these hila
are actually situated anterior medially so um they're not perfectly medial and that's because
the lateral borders of the kidneys are situated posterior laterally
these kidneys even within the retroperitoneum which we'll discuss uh may change their position
depending on what an individual is doing so if they are standing or or sitting upright gravity
may act upon them as an individual breathes and their diaphragm depresses they may move inferiorly
slightly with uh with that movement and to really appreciate what we're seeing here
you would you would have to understand that all of the gi organs would be removed and that's why we
see the the kidneys or we encounter them through dissection typically with our gi sessions once
we are able to remove a lot of those organs and the organs which typically obscure the kidney
are those that are derived from the embryonic foregut so the the stomach
the the duodenum pancreas things such as that so within the abdomen the the kidneys exist
in the retroperitoneal space uh we'll get into the granular details of the peritoneum in the gi
sessions but your short preview of it is that it is a serous membrane
which lines the abdominal pelvic cavity so that serous membrane
will be both on the walls as well as on the viscera
and so we'll have both parietal and visceral components and then
we'll have the cavity between those parietal and visceral
components well the retroperitoneal space is everything which is posterior to that
peritoneal membrane and we can subdivide it a number of ways let me erase all of this
first let's orient ourselves so anterior is there posterior is there here is the midline
and this is the right side and i can tell that because the the liver is here so this is a
inferior view of what's going on let me just outline the the kidney
for us because this is sort of the the star of the show
so that is the the kidney and we can see that it is in the retro retroperitoneal space
here is that parietal peritoneum
that i'll outline and that retroperitoneal space is divided um into subspaces by various fascia um
there there is um there are a number of ways that we can conceptualize
um this fascia but if we if we look surrounding the uh the kidney
is the peri-renal fascia
that perirenal fascia may be conceptualized a number of ways
so it might be considered one contiguous layer of fascia or it may be conceptualized
separately as an anterior layer of fascia and this would be called Gerota's fascia
and there's also a posterior layer of fascia called zucker candles fascia
which is there and these two layers of fascia meet laterally to form the lateroconal fascia
and that lateroconal fascia goes out to blend with the parietal peritoneum so that's that's another
way that we can conceptualize this space so regardless of what we want to call uh these fascia
or these these foshi uh for our purposes we'll refer to everything as peri renal or renal fascia
we can see that there are para-renal spaces so there is an anterior peri-renal space in a
posterior peri-renal space that anterior perirenal space will often times especially more anteriorly
and immediately envelop various property neal gi elements so sometimes it's referred to as
the the gi space whereas the posterior perirenal space typically only contains
adipose connective tissue or or fat now within this perirenal fascia is the peri renal
with an "I" peri-renal space and that peri-renal space is going to contain the
kidneys the suprarenal glands the proximal ureters and a copious amount of peri-renal adipose
connective tissue and this space also includes or invades the renal sinus which we can see here
so very frequently um the the entirety of the peri-renal fascia is referred to as
garrotus fascia even though in the the technical sense of the term corrodus fascia is only the
anterior aspect of that peri-renal fascia it's very dense yet elastic we can conceptualize it
as kind of an inverted cone that is largest superiorly and is very variable in its course
and its extent inferiorly it tends to uh to end at the uh at the common iliac
vessels we can see there's the common iliac artery and the common iliac vein would be there and it's
surrounding we can't see it here because it's not pierced but it's surrounding the suprarenal glands
the kidneys and the uh the ureters as they descend down in that that retroperitoneal space
so here we can see that uh that goro's fascia removed and we can see the suprarenal
gland we can see the the right kidney there we can see the various hylar contents so a renal
artery a renal vein and an accessory renal artery we can also see the hilum there going into the
ureter and we can see the peri-renal fat much of which has been removed in order for us to see this
so it's it's probably good to keep these contents in mind if you ever hear the the terminology of
a simple versus a radical nephrectomy a nephrectomy is the removal of a kidney
a simple nephrectomy usually happens with some benign disease process that might
necessitate the removal of the kidney whereas a radical nephrectomy involves the removal
classically of at least the kidney and oftentimes the super renal gland the ureter
and all of the peri renal fat so generally the entire contents of the peri renal space
so we've discussed the uh the superficial features of the kidney the various borders and poles
the hilah and how they are situated and their relative relationships to various vertebral levels
we've also discussed the spaces which surround the kidneys so the anterior and posterior
para-renal spaces superficial to the peri-renal fascia
the peri-renal space deep to the perirenal fascia this is your summary slide thank you for your time