The kidneys are paired retroperitoneal organs located in the posterior abdominal cavity. Each kidney is reddish-brown and ovoid in shape, measuring approximately 10-12 cm long. The kidneys receive blood supply from the renal arteries and drain into the renal veins. The internal anatomy of the kidneys includes the renal cortex, medulla, pyramids, calyces and pelvis which collect urine drained from nephrons. Variations can occur in the number and branching pattern of renal vessels.

1. ANATOMY OF KIDNEY
1
DR.MANOJ ARYAL
DM RESIDENT NEPHROLOGY
NAMS BIR HOSPITAL

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ANATOMY OF
KIDNEY
• Paired ovoid, reddish-brown retroperitoneal organs
situated in the posterior part of the abdomen on each
side of the vertebral coloumn
• Lie on the psoas muscles; thus the longitudinal axes
of the kidneys are oblique .
• The upper poles more medial and posterior than
the inferior poles.
• The medial aspect of each kidney is rotated anteriorly
at an angle of approximately 30 degrees.

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• The exact position of the kidney within
the retroperitoneum varies
The kidneys move inferiorly approximately
3 cm (one vertebral body) during
inspiration and during changing body
position from supine to the erect.

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DIMENSIO
NS
• Length- 10 to 12 cm
• Width- 5.0 to 7.5 cm
• Thickness- 2.5 to 3.0 cm.
Weight of kidney = approx. 125-170
gm. ( 10- 15 gm lighter in females).

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Right kidney vs left
kidney
Right kidney Left
kidney
• Reside betweenthe top
of the 1st lumbar
vertebra to the bottom
of the 3rd lumbar
vertebra.
• The right kidney is
slightly shorter and
wider because of
downward
compression by the
liver.
• The right kidney is
related to the 12th
• Between the 12th
thoracic vertebra and
the 3rd lumbar
vertebra.
• Left kidney is related
to the 11th and 12th
ribs

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RELATIO
NS
• Surfaces of kidney are -
anterior and
posterior.
• Borders are - medial and lateral.
• Poles of kidney are – superior and
inferior.
• Anteriorly kidney is related -
abdominal viscera
• Posteriorly - osteomuscular area

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ANTERIOR
RELATIONS
RIGHT KIDNEY LEFT
KIDNEY
• right adrenal gland
• liver
• second part of
duodenum
• ascending colon
• hepatic flexure of colon.
• Left adrenal
• Pancreas
• splenic vessels
• Stomach
• Spleen
• Dj flexure
• Ligament of trietz
• Descending colon
• Splenic flexure of
colon
• Loops of jejunum.

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POSTERIOR RELATIONS OF
KIDNEY
LEFT KIDNEY RIGHT
KIDNEY
• Projection of 11th rib
• Area for diaphragm
• Projection of 12th rib
• Area for aponeurosis
of transversus
abdominis muscle
• Area for
quadratus
lumborum
muscle
• Area for psoas major
• Area for diaphragm
• Projection of 12th rib
• Area for aponeurosis
of transversus
abdominis muscle
• Area for quadratus
lumborum muscle
• Area for psoas major
muscle

11. LEF
T
RIGH
T
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APPLIED
ANATOMY
• Posterior reflection of the pleura
extends inferiorly to the 12th rib
• Lung edge lies above the 11th rib (at the
10th intercostal space)
• Risk of injury to the lung from a 10th
intercostal percutaneous approach to
the kidney

14. Relationship to ribs and
pleura
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MEDIALBORD
ER
» In medial border of each kidney there is a vertical fissure
called renal hilum/porta
• Renal vessels, nerves, lymphatics, enter and exit through
through hilum
• Concavity of hilum is continous with deep declivityin
medial border of kidney called renal sinus
• Within renal sinus is renal pelvis, a funnel shaped sac
formed by widely expanded portion of proximal ureter and
by junction of major calices

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• Intra renal pelvis denotes the pelvis
that is almost covered by renal
parenchyma.
• Renal pelvis almost bifurcates or
trifurcates within the sinus producing
2/3 major calyx.
• Each major calyx again divide into 5-14
minor calyxes receiving collecting ducts (
500).
• Renal pelvis commonly lies posterior to
renal vessels.

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• LATERALBORDER :
Related to perirenal fascia, gerota’s fascia,
para renal fascia.

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GEROTA’S FASCIA
• Encloses the kidney & perirenal fat
and adrenals.
• Anatomic barrier to spread of
malignancy
• Superiorly and laterally it is closed
• Medially it crosses the midline to fuse
with the fellow of opposite Side
• Inferiorly it remains open- perinephric
fluid can track into pelvis

19. RENAL
FASCIA
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• Two distinct regions :-
Cortex - pale outer region
Medulla - darker inner region
• Renal medulla - 8 to 18 striated, distinct, conically shaped
areas called renal pyramids.
• The apex of the pyramids forms the renal papilla, and each
papilla is cupped by an individual minor calyx.
• The base of the pyramids is positioned at the corticomedullary
boundary.
• Renal cortex is approximately 1 cm in thickness and covers
the base of each renal pyramid peripherally and extends
downward between the individual pyramids to form the
columns of Bertin .

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• Interlobar arteries traverse these
columns of Bertin
• Therefore percutaneous access to the
collecting system is usually performed
through a renal pyramid into a calyx to
avoid these columns of Bertin containing
larger blood vessels
• The functional unit of the kidney is the
nephron. Approximately 0.4 to 1.2 million
nephrons are found in each adult kidney.

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• The cortex made up of the glomeruli with
PCT & DCT.
• The renal pyramids are made up of
loops of Henle and collecting ducts.
• Ducts join to form the papillary ducts (about
20), which open at the papillary surface
(area cribosa) and drain urine into the
collecting system(into the fornix of a minor
calyx).

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MINOR
CALYX
• The renal papillae drain into the minor
calyces, (the most peripheral portions of
the intrarenal collecting system).
• Range in number from 5 to 14 (mean- 8)
• Simple (drains one papilla)
• Compound (drains two or three papillae)

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• Three calyceal groups: upper, middle, and lower.
• Minor calyces, either directly or after coalescing
into major calyces, drain by infundibula into the
renal pelvis
• Compound calyces of the poles of the
kidney are oriented facing their respective
poles.
• Simple calyces usually come in pairs, with one
facing anteriorly and one facing posteriorly

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• Drainage of the upper pole into the renal pelvis is
by a single midline infundibulum in the majority of
kidneys.
• Drainage from the lower pole is via a single
infundibulum in about half of human kidneys.
• The middle calyces are typically arranged in a
series of paired anterior and posterior calyces.
• In about two thirds of kidneys, there are two major
calyceal systems—an upper one and lower one—and
the middle calyces drain into either or both systems

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RENAL
VASCULATURE
• The renal arteries arise from the aorta at the level of the intervertebral
disk between the L1 and L2 vertebrae.
• Each artery divides into five segmental end arteries that do not
anastomose significantly with other segmental arteries.
• The renal artery usually divides to form anterior and posterior divisions.
• The anterior division supplies anterior two thirds of the kidney, and the
posterior division supplies the posterior one third of the kidney.
• Typically, the anterior division divides into four anterior segmental
branches: apical, upper, middle, and lower.
• The posterior segmental artery - first and most constant branch, which
separates from the renal artery before it enters the renal hilum

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SEGMENTAL
BRANCHES
• End arteries- so injury lead to segmental infarction.
• First and most constant branch POSTERIOR
SEGMENTAL BRANCH
• Four anterior branches
• APICAL
• UPPER
• MIDDLE
• LOWER
• Posterior segmental artery passes posterior to renal
pelvis

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• In the renal sinus, the segmental arteries branch into lobar
arteries, which further subdivide in the parenchyma to form
interlobar arteries.
• The interlobar arteries progress peripherally within the
cortical columns of Bertin, avoiding the renal pyramids
but in a close association with the minor calyceal
infundibula.
• At the base (peripheral edge) of the renal pyramids, the
interlobar arteries branch into arcuate arteries.
• Instead of moving peripherally, the arcuate arteries parallel
the edge of the corticomedullary junction and move
radially, where they eventually divide to form the afferent
arteries to the glomerulus.

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ANOMALIES OF RENAL
ARTERY
• Multiple renal arteries- kidney supplied by more
than one artery. MC on left side.
• Accessory renal artery – 2 or more branch
supply the same renal segment. MC on left side
30 to 35%
• They enter either in upper pole/ lower pole of
kidney.
• Such accessory artery can cause ureteric
obstruction lead to secondary HUN..
• But ligation of accessory renal artery result in a
portion of infarction
• Arterial anomalies are more common on left
and venous anomalies are more common
on right.

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COMMON ANATOMIC
VARIANTS OF
VESSEL
• Occurs in 25- 40%
• M.C is supernumery arteries- More
common on Left side.
• Lower pole arteries can cross ant to
collection system and cause PUJ
obstruction

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RENAL
VEIN
• The vein is located directly anterior to
the renal artery.
• This position can vary up to 1-2 cm
cranially or caudally relative to the artery

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LEFT RENAL
VEIN
• The left renal vein - 6 to 10 cm in length
and drains into IVC after passing posterior
to the superior mesenteric artery and
anterior to the aorta
• Left renal vein enters the IVC at a slightly
more cranial level and a more
anterolateral location
• The left renal vein receives the left
adrenal vein superiorly, lumbar vein
posteriorly, and left gonadal vein
inferiorly

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RIGHT RENAL
VEIN
• The right renal vein is generally 2 to 4
cm in length and enters the right lateral
to posterolateral edge of the IVC
• Right renal vein enters the IVC at a
slightly more caudal level.
• The right renal vein typically do not
receive any branches

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• Unlike the arterial supply, the venous
drainage communicates freely through
“Venous Collars” around the infundibula,
• Extensive collateral circulation is
present in the venous drainage of the
kidney.
• Surgically, this is important, because unlike
the arterial supply, occlusion of a
segmental venous branch has little effect
on venous outflow

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BRODEL’SLINE/AVASCULAR
PLANE
• Slightly behind the convex border at the
posterior half of kidney (approximately 2/3
rd way from lateral border ).
• Incision in this area will permit to
remove stone within renal calices
with minimal damage.

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LYMPHATI
CS
• Largely follow blood vessels through the
column of bertin.
• Lymphatics empty to LN near renal hilum
• L KIDNEY:-
-Lt lateral para- aortic LN
• R KIDNEY:-
-Rt inter aortocaval and Rt lateral
para caval LN and anterior and posterior
inferior venacaval nodes.

45. LYMPHATICS OF RIGHT
KIDNEY
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46. LYMPHATICS OF LEFT
KIDNEY
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NERVE
SUPPLY
• SYMPATHETIC - From T8 to L1 through
celiac and aortico renal ganglion
- Vasoconstriction
• PARA SYMPATHETIC- From vagus
- vasodilatation

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