Kidney anatomy refers to all the tissue components of the kidneys. They have a distinct anatomy. Kidneys are bean-shaped organs and dark red in color

1. Presented by: Nesar Ahmad
Moderator: Dr Raghib Hussain
Aktc. d/o jarahat
10/07/2017
ANATOMY of
kidney

2. Introduction
• Urinary system comprises the kidneys, ureters,
urinary bladder, and urethra.
• The structures of kidney precisely maintain the
internal chemical environment of the body—perform
various excretory and regulatory functions.

4. EMBRYOLOGY
• Development starts at 4th week
• The urogenital glands and ducts develop from the intermediate
mesoderm.
• primordial components ----pronephros ,mesonephros,metanephros ,
and the mesonephric and paramesonephric ducts.
• pronephros :appear as solid cell groups in cervical region ,which then
regresses
• mesonephros : forms glomerulus bowman’s capsule, which opens
into mesonephric duct
• except mesonephric duct rest of these structures regresses
• mesonephric duct forms internal genitalia in males , an out growth
from it forms ureteric bud

5.  metanephros forms excretory part of
definitive kidney upto DCT
 ureteric bud forms the rest, from collecting
tubules upto trigone of the bladder
 interaction between metanephros and ureteric
bud initiates development of kidney

6. Kidneys
LOCATION:
 The Kidneys (renes) are a pair of excretory organs situated
on the posterial abdominal wall, one on each side of
vertebral column, covered by the peritoneum and
surrounded by a mass of fat and loose areolar tissue.
 The kidneys occupy the epigastric, hypochondriac, lumbar
and umblical regions
 Vertically they extend from the upper border of twelfth
thoracic vertebra to the center of the body of third lumbar
vertebra.

8. The right kidney is usually slightly lower than the left,
and the left kidney is a little nearer to the median plane than
the right.
The tranpyloric plane passes through the upper part of the
hilus of the right kidney, and through the lower part of the
hilus of the left kidney.
The long axis of each kidney is directed downwards and
laterally.
The upper poles of kidneys are more medial and posterior
than the inferior poles.

9. Kidneys
COLOUR AND SHAPE:
Reddish brown in colour and bean shaped.
HEIGHT & WEIGHT:
• Each kidney is about 11cm long, 6 cm wide, and rather
more than 2.5 cm thick. The left is somewhat longer and
narrower than the right.
• In the adult male, the kidney weighs 125 to 170 gm; in the
adult female, 115 to 155 gm.
• The combined weight of the two kidneys in proportion to
that of the body is about 1:240.
• The newborn kineys in proportion to the body weight are
about three times larger than the adult kidneys.

10. 11 cm
6cm
3cm
10

11. Surface marking
The kidney can be marked both on the back as well as
on the front.
On the back: it is marked within Morris
parellelogram which is drawn in the following way.
2 horizontal lines-T11 & L3 spine
2 vertical lines- 2.5 & 9cm from median plane
Hilum 5cm from median plane,near the level of
transpyloric plane,
Little above it in the left
Little below it in the right

13. On the front: the bean shaped kidney is marked
with the following specifications:
1) On the right side the center of the hilum lies
5cm from the median plane, a little below the
transpyloric plane.
On the left side it lies 5cm from the median plane,
a little above the transpyloric plane.
2) the upper pole lies 4 to 5cm from the midline,
halfway between the xiphisternum and the
transpyloric plane right one, a little lower.
3) The lower pole lies 6 to 7cm from the midline
on the right side at the umblical plane and on the
left side at the subcostal plane.

15. CAPSULES OR COVERINGS OF
KIDNEYS• Fibrous capsule –
– Thin membrane, covers the kidneys, may be separated from them
• Perirenal fat –
– Layer of fat surrounding the fibrous capsule and also filling up area in
the renal sinus
• Renal fascia of Gerota-
– Fibroareolar sheath surrounding the kidney and perirenal fat
– helps maintain organ position
– superiorly, is continuous with fascia of inferior diaphragm
– medially the left and right fascia blend with each other anterior to
abdominal aorta and IVC
– posterior layer of fascia blends with fascia overlying psoas
Anterior layer– fascia of Toldt
Posterior layer – fascia of Zucherkandl
• Pararenal fat –
– Fat that surrounds the renal fascia, more abundant posteriorly and at
lower pole
– Fills up paravertebral gutter and forms a cushion for the kidney

18. Relations of kidney with other
organs and structures
kidney has :
Two poles (extremity) –
– Upper/cranial extremity – broad due to presence of adrenal
glands
– Lower/caudal extremity – pointed
Two borders
– Lateral – convex
– Medial – concave with hilum in the middle
Two surfaces
– Anterior – irregular
– Posterior - flat

19. Surfaces
Ventral/anterior surface:
The ventral surface of each kidney is convex and
faces ventralward and slightly lateralward

20. Anterior surfaces right kidney
It’s relations
Upper part
With right suprarenal glands
With the visceral surface of the liver
With second part of duodenum
Lower part
Laterally With right colic (hepatic) flexure of
ascending colon
Medially With small intestine

21. Anterior surface of left kidney
It’s relations:
Left suprarenal gland
Spleen
Body of pancreas
Left renal vessels
Posterior surface of stomach
Splenic flexure
jejunum
Peritoneum of omental bursa
Peritoneum of the greater sac

22. The ventral surfaces of the kidneys, showing the areas of contact of neighboring viscera

23. Posterior/Dorsal surface
The posterior surface of each kidney is directed dorsalward and
medialward.
It is embeded in areolar and fatty tissue and entirely devoid of
peritoneal covering.
It’s relations
Diaphragm
Medial and lateral lumbocostal arches
Muscles: psoas major, quadratus lumborum, tendon of
transversus abdominis
Arteries: subcostal and one or two of the upper lumbar arteries
Nerves: subcostal, iliohypogastric and ilioinguinal nerves
On the right side: 12th rib
On the left side: 11th & 12th ribs both

24. The dorsal surfaces of the kidneys, showing areas of relation to the parietes

26. Borders
Kidney has two borders
1. Lateral border (external border): is convex and and
directed towards the posterolateral wall of the
abdomen. On the left side it is in contact with the
spleen.
2. Medial border (internal border): is concave in the
center and convex toward either extremity; it is
directed anteriorly and a little downward. Its central
part has a deep longitudinal fissure. This fissure
named the Hilum, transmits the renal vessels, renal
nerves and pelvis. Above the hilum the medial border
is in relation with the suprarenal gland; below the
hilum, with the ureter.

27. The medial border

28. Extremities
1. Cranial extremity (upper pole): is thick and round and
is nearer the median line than the caudal extremity. It is
surrounded by suprarenal gland.
2. Caudal extremity (lower pole): is smaller and thinner
than the superior and farther from the median line.

29. General structure of the kidney
The kidney is invested by a fibrous tunic or capsule that forms a
firm, smooth covering to the organ. The tunic can be stripped off
easily, so the surface of the kidney becomes smooth and deep
red.
If a vertical section of the kidney were made from its convex to
its concave border, it would be seen that the hilum expands into
a central cavity, the renal sinus; this contains the renal pelvis
and the calyces, surrounded by some fat in which the branches
of the renal vessels and nerves are embedded.
The minor renal calyces, numbering 4 to 13, are cup shaped
tubes. They unite to form two or three short tubes, the major
calyces, and these in turn join to form a funnel-shaped sac, the
renal pelvis.
As the pelvis leaves the renal sinus, it diminishes rapidly in
caliber and merges insensibly into the ureter, the excretory duct
of the kidney

30. The kidney is composed of an internal medullary and an
external cortical substance.
The medullary substance consist of a series of striated
conical masses, termed the renal pyramids, of which there
are 8 to 18. Their bases are directed toward the
circumference of the kidney, while their apices converge
toward the renal sinus, where they form prominent papillae
projecting into the lumen of the minor calyces.
The cortical substance is reddish brown, soft and granular.
It lies immediately beneath the fibrous tunic, arches over the
bases of the pyramids, and dips in between adjacent
pyramids toward the renal sinus. The parts dipping between
the pyramids are named renal columns, while the portions
that connect the renal columns to each other and intervene
between the bases of the pyramids and the fibrous tunic are
called the cortical arches.

32. GROSS STRUCTURE OF THE KIDNEY
Longitudinal section there are 3 areas.
I. Fibrous capsule
II. Cortex
III. Medulla

33. 33
RENAL FIBROUS CAPSULE: surrounds the kidney,
made of dense fibrous connective tissue.

34. 34
CORTEX: A reddish brown layer of tissue
immediately below the capsule and out side the
pyramids.

35. 35
MEDULLA: the inner most layer consisting of pale
conical shaped striations called renal pyramids.

36. Surface anatomy of the Kidney
• Hilum is located on
the medial surface
HILUM: it is the concave medial border or deep
fissure of the kidney where the renal blood & lymph
vessels , urater & nerve enters.
Renal Sinus:
Space within hilus.
Kidneys receive
blood vessels and
nerves.

37. 37
RENAL PELVIS: it is the funnel shaped structure
which acts as a receptacle of the urine formed by
the kidney.

38. Renal Vasculature
• Renal arteries branch from the abdominal aorta
laterally between L1 and L2, below the origin of the
superior mesenteric artery
• The right renal artery passes posterior to the IVC
• There may be more than one renal artery (on one or
both sides) in 20-30% cases

39. Renal Vasculature
• Renal veins drain into inferior vena cava
• Renal veins lie anterior to the arteries
• Left renal vein is longer and passes anterior to the
aorta before draining into the inferior vena cava.

40. Aorta
Renal artery
Segmental artery
Interlobar artery
Arcuate artery
Interlobular artery
Afferent arteriole
Glomerulus (capillaries)
Nephron-associated blood vessels
Inferior vena cava
Renal vein
Interlobar vein
Arcuate vein
Cortical radiate
vein / interlobular vein
Peritubular
capillaries
and vasa recta
Efferent arteriole
Path of blood flow through renal blood vessels

42. Regulates blood flow to the kidney by
causing vasodilation or vaso constriction of
renal arterioles.
Autonomic plexuses in the abdomen and pelvis

43. Renal Lymphatics
The lymphatics of the kidney drain into the lateral
aortic nodes located at the level of origin of the
renal arteries

44. Histological structures of the kidney
Histologically each kidney is composed of 1-3
million uriniferous tubules. Each tubule consists of
two parts.
1) The secretory part, called the nephron, which is
the functional unit of the kidney. It comprises two
parts.
a) Renal corpuscle or Malphigian corpscle; made up
of glomerulus and Bowman’s capsule
b) Renal tubule; made up of the proximal
convoluted tubule, loop of Henle with its
descending and ascending limbs, and the distal
convoluted tubule.

45. 2) Collecting tubule: which begins as a junctional
tubule from the distal convoluted tubule. Many
tubules unite together to forms the ducts of Bellini
which open into the minor calices through the renal
papillae.

47. Kidneys functions
• Urine formation
• Excretion of waste products
• Regulation of electrolytes
• Regulation of acid–base balance
• Control of water balance
• Control of blood pressure
• Renal clearance
• Regulation of red blood cell production
• Synthesis of vitamin D to active form
• Secretion of prostaglandins

48. Applied anatomy
Congenital anomalies of the kidney:
Agenesis of kidney: absence of kiney on one side is often
associated with absence of ureter, either one kidney is absent
with ureter or ureter and pelvis is present but the kidney is
absent. In both these cases the present single kidney
becomes hypertrophied and functions almost double the
normal
Hypoplasia and Dysplasia: when the metanephrogenic cap
fails to develop properly, such condition may develop when
one kidney becomes small and less functioning.
Supernumerary kidney: there may be more than one kidney
on one or both sides.

49. Duplex kidney & ureter: Sometimes the pelvis is
duplicated, while a double ureter is not uncommon.
Foetal lobulation: in the foetal life the kidney is lobulated
and is made up about 12 lobules, after birth the lobules
gradually fuse, however the evidence of foetal lobulation
may persists.
Fused kidney: three types are found:-
1) Horse shoe kidney is caused by fusion of lower poles of
both kidneys with a bridge.
2) Unilateral fused kidney or crossed renal ectopia: in
which both kidneys may lie on any one side of the body.
3) S-shaped kidney

50. Defect in the position of the kidney or ectopic kidney: One or both
kidneys may be misplaced congenitally and remain fixed in this
abnormal position. They may be displaced into the iliac fossa, over
the sacroiliac joint, onto the promontary of the sacrum, or into the
pelvis between the rectum and bladder.
Floating kidney: The kidney may also be displaced congenitally
but not fixed.they can move up and down within the renal fascia, but
not from side to side.
Movable kidney: The kidney may also be misplaced as an acquired
condition; in these cases the kidney is mobile in the tissues that
surround it, moving with the capsule in the perinephric tissues.
Cystic disorders of the kidney: Nonunion of the secratory and
collecting parts of the kidney results in the formation of either
polycystic kidney or medullary sponge kidney or unilateral
multicystic kidney or solitary renal cyst.
Renal arteriovenous fistula: may be congenital in 25% of cases

51. Applied anatomy cont...........
• Renal injuries
• Perinephric abcess
• Nephroptosis
• Renal cyst
• Renal calculi
• Glomerular nephritis
• Renal transplantation

52. Renal injuries
Renal injuries can be classified into slight, severe and critical.
Slight injuries comprise those where the parenchyma is
damaged without rupture of the capsule or extension of the
laceration into the renal pelvis or calyx. This produces
subscapular haematoma. This condition does not produce
haematuria but slight tenderness at the renal angle can be
elicited.
Severe injuries are those where the capsule is broken, renal
pelvis or calyx is distorted. This produces haematuria or a mass
in the loin from a perirenal haematoma. There may be leakage
of urine in the retroperitoneal tissue.
Critical injury is such when the kidney is shattered or there is a
tear in the renal artery or one of its branches. The patient rarely
survives after this type of injury.

53. Perinephric abcess
o Pus around the kidney
o The attachment of renal facia determine the path
of extension of perinephric abcess.
o The pus from abcess may force its way into
pelvis between the loosely attached anterior and
posterior attached layers of renal fascia.

54. Nephroptosis
• Because the renal fascia do not fuse firmly
inferiorly to offer resistance, abnormaly mobile
kidney may descend more than 3cm to their
normal position when body is erect.
• Distinguished from an ectopic kidney by the
length of ureter.

55. Renal cyst
• Solitary or multiple
• Adult polycystic disease of kidney is an
important cause of renal failure.
• The kidneys are markedly increased by 5 cm of
the normal size.

56. Renal calculi
• Description: common cause of urine obstruction
• Etiology: low urine volume, dehydration, UTI,
prolonged bedrest
• Four types of kidney stones:
– Calcium stones (i.e., oxalate or phosphate)
– Magnesium ammonium phosphate stones
– Uric acid stones
– Cystine stones

57. Glomerular nephritis
• Glomerular nephritis refers to an inflammation of
the glomerulas .
• Results in nephrotic syndrome.
• Oedema
• Increased protein in urine.
• decreased protein in urine.

58. Hydronephritis
• Expansion of the kidney with urine
– Increased pressure inside the renal capsule
– Compartment syndrome compresses blood
vessels inside kidney
– Renal ischemia

59. Renal transplantation
• Established operation for chronic renal failure.
• Kidney can be removed from donor without
damaging the supra renal gland because of
weak septum of renal fascia that separates the
kidney from this gland.
• Site- iliac fossa of greater pelvis.
• Renal artery and veins are joined to the external
iliac artery and vein respectively. Ureter is
sutured.

61. Questions?