radiological and gross anatomy of genitourinary system

1. Anatomy of genitourinary system
Dr. Kishor Bhattarai
1st year resident
Department of Radiodiagnosis,NAMS

2. Overview
• Anatomy renal system and
common variants
• Anatomy of male and female
reproductive organs and
common variants

3. Kidney,ureter,bladder and urethra
• The kidney functions to maintain
electrolyte homeostasis and waste
excretion
• empty medially into ureters,which
courses inferiorly into the pelvis
and enter the bladder
• urine is temporarily stored in
bladder till it is cleared via urethra

4. Kidneys
• on either side of lower thoracic and
upper lumbar spine
• usual location - upper border of 12th
thoracic vertebra and lower border of
3rd lumbar vertebra
• right is slightly lower than the left
(2cm)
• long axis is directed downwards and
laterally-upper poles lie nearer to the
median plane
• lower pole is 2-3 cm anterior to the
upper pole

5. kidneys
• bean shaped
• poles
upper-broad due to adrenal gland
lower -pointed
• borders
lateral- convex
medial-concave with hilum
• surfaces
anterior- irregular
posterior - flat

6. • normal size in adults : 10-15 cm
• right kidney is shorter than the
left normally but not by more
than 1.5cm
• size is approximately three and a
half lumbar vertebra and their
associated discs on a radiograph

7. Anterior relations of kidney
• right
 right adrenal gland
 liver
 2nd part of duodenum
 hepatic flexure of colon
 small intestine
• left
 left adrenal gland
 spleen
 stomach
 pancreas
 splenic flexure
 jejunum

8. Posterior relations of kidney
• right
-diaphragm
- medial and lateral arcuate ligaments
muscles
psoas major
quadratus lumborum
transvese abdominis
blood vessels
subcostal vessels
iliohypogastric nerve
ilioinguinal nerve
12th rib
• left
-diaphragm
- medial and lateral arcuate ligaments
muscles
psoas major
quadratus lumborum
transvese abdominis
blood vessels
subcostal vessels
iliohypogastric nerve
ilioinguinal nerve
 11th and 12th rib

10. Fat and fascia surrounding the kidney
• fibrous capsule
covers the kidney
• perirenal fat
layer of fat surrounding the fibrous
capsule and also filling up areas in
renal sinus
• renal fascia
fibroareolar sheath over the
condensed fat
• pararenal fat
surrounds the renal fascia,more
abundant posteriorly

11. Internal structure
• outer cortex
cortex arches over the bases of
pyramids and renal column of
bertin that separates medulla into
pyramids
• inner medulla
consists 8-16 pyramids
the apex of each pyramid projects
into a calyx as a renal papilla

12. Renal collecting system
• pappilae positioned in the apex
of pyramids drains into the
fornix of minor calyces
• they join to form 3 -4 major
calyces
• major calyces join to form renal
pelvis
• the renal pelvis drains into the
muscular tube called ureter

13. Extrarenal pelvis
• normal variant of pelvis having
pelvis outside the confinement
of renal hilum
• more distensile than the
intrarenal pelvis thus it may be
confused for proximal
hydroureter

14. Retroperitoneal space
• lies between the posterior
parietal peritoneum and anterior
to the transversalis fascia
• divided into three spaces by the
perirenal fascia
anterior pararenal space
perirenal space
posterior pararenal space

15. Anterior pararenal space
• it is bounded by
anteriorly: posterior parietal
peritoneum
posteriorly: Gerotas’fascia
laterally: lateral conal fascia
superiorly:diaphragmatic fascia
inferiorly:pelvic brim

16. Contents
• pancreas and retroperitoneal
portion of duodenum centrally
• ascending colon on right
• descending colon on left

17. Perinephric space
• space between anterior Gerota’s and posterior Zuckerandal fascia
• laterally fuse to give lateral conal fascia
• superiorly anterior fascia blends with right inferior coronary ligament
near bare area of liver while posterior fascia blends with diaphragmatic
fascia
• medially blends with the connective tissue surrounding great vessels
• inferiorly relatively open to retroperitoneal space of abdomen and pelvis

18. Contents
• The perinephric space contains
kidneys
adrenal gland
proximal collecting system
renal vasculature
perirenal vascular network
lymphatics
prominent amount of fat which are septated
The largest fat accumulation in perirenal space is medial to the lower pole
of the kidney,this is the preferential location where abscesses,hematomas
and urinomas may accumulate

20. Posterior pararenal space
• space between the posterior
perinephric fascia and adjacent
transversalis fascia
• contains only fat

21. Renal vasculature
• renal venous drainage
renal veins drain into inferior
venacava
they lie anteriorly to arteries in
renal pelvis
left renal vein is longer and passes
anterior to aorta before draining
into the inferior venacava
the left gonadal vein drains into left
renal vein while right gonadal vein
drains directly into the inferior
venacava

22. Renal arteries
• branches from abdominal aorta laterally between L1 and L2 below
the origin of superior mesenteric artery
• right renal artery is longer, higher/same level compared left renal
artery and passes posterior to ivc
• both renal arteries usually have two divisions
one passes posterior to renal pelvis and supplies posterior upper part of the
kidney
another anterior branch supplies upper anterior and entire lower kidney
• within the hilum ,devide into five segmental branches as interlobar
arteries (in between the lobes/pyramids)-arcuate arteries( at CMJ and
the base of pyramids)-interlobular arteries(run into capsule)

24. transverse image of right renal artery as it
extends from the aorta on longitudinal scan of the ivc and aorta , the right renal artery can
be seen as a circular structure posterior to the inferior venacava

26. Accessory renal artery
• initially the kidneys are suplied
by lateral sacral branches of
aorta
• during ascent from pelvis they
acquire successively higher
lateral branches of aorta upto
the definitive renal arteries at
the level of L1-L2
• failure of regression of inferior
arteries give rise to accessory
renal arteries

27. Brodel’s avascular plane
• The avascular plane of of brodel is the section of renal parenchyma
between 2/3rd anterior and 1/3rd posterior kidney on cross section
• the reason for its relative avascularity is that it represents the plane
where the anterior and posterior segmental renal artery branches
meet
• it is located just posterior to lateral convex border of the kidney and
permits a relatively safe access route to the pelvicalyceal system for
nephrostomy

29. Renal anatomical variation
• persistent fetal lobulations
due to incomplete fusion of
developing renal lobules
seen as smooth indentations of
renal outline

30. • Dromedary hump
local bulge /covexicity along
lateral border of the left kidney
it is due to impression of spleen or
fetal lobulation

32. Junctional parenchymal defect
• due to due to incomplete fusion
of renal lobes
• located between upper and mid
poles of the kidney
• typically triangular in shape

33. • Hypertrophied column of Bertin
Columns of Bertin represent the
extension of renal cortical tissue
which separates the pyramids
 They become of radiographic
importance when they are
unusually enlarged and may be
mistaken for a renal mass.

34. Ureters
• 25-30 cm and 2-8 mm in in
diameter
• it has 4 parts
pelvis
abdominal
pelvic
intravesical

35. Pelvis course
• passes behind the second part of
duodenum

36. Abdominal Course
• retroperitoneal
• right and left ureter lie laterally
to ivc and aorta respectively
• it passes vertically anteriorly on
medial edge of the psoas muscle
which separates it from
transverse process of lumbar
vertebra (L2-L5)

37. Pelvic part of ureter
• ureter crosses the front of
bifurcation of common iliac
artery to reach the pelvis
• descends downward and
backward along the lower
border of internal iliac artery
• then it curves forward and
medially to reach the bladder

38. Close to the bladder
• male
passes above
seminal vesicle
and crossed by
vas deferens
• female
passes under
uterine artery in
the base of
broad ligament
close to the
lateral fornix

39. Areas of constrictions
• Ureteropelvic junction(PUJ)
• Bifurcation of common iliac
artery
• Ureterovesical junction(VUJ)

40. Vascular supply of ureter
• receives from different arteries along its
descending course
 renal artery branches
 gonadal artery branches
 abdominal aorta
 internal iliac
 superior vesical
 uterine
 middle rectal
 vaginal
 inferior vesical
• venous drainage is via corresponding
renal,gonadal and iliac veins

41. Lymphatic drainage

42. Urinary bladder
• hollow muscular vesicle for storing urine temporarily
• higher in position in children and slightly higher in males than females
• pyramidal shaped organ when empty and oval when filled
• triangular base posteriorly,an apex behind the symphysis pubis ,one
superior and two posterolateral surfaces
• separated from the pubic symphysis by the retropubic fatty space of
Retzius

45. Peritoneal reflection
• located only on superior surface of the bladder
males:entire superior surface is covered by peritoneum
females:
anterior 2/3rd covered
posterior 1/3rd uncovered,related to supravaginal part of cervix

46. Mobility and support of bladder
• bladder is usually free to move except in neck region which lies 3-4
cm from pubic symphysis due to ligaments
males : puboprostatic ligments
females: pubovesicle ligaments

47. Blood supply and lymphatics of bladder
• arterial suppy via
superior and inferior vesicle artery
• venous drainage via
 vesical venous plexus to internal iliac vein
• lymphatics
along the blood vessels mainly via external iliac and then para-aortic
nodes

48. Male urethra
• approx. 20 cm in length
• from internal urethral spincter at the neck of bladder to the external
urethral orifice at the tip of penis
• divided into
posterior urethra- prostatic and membranous part
anterior urethra-penile urethra/spongy urethra
• protatic urethra is the widest part appx. 3cm in length and receives
ejaculatory duct
• membranous urethra is the shortest and narrowest part appx 1.5cm
• penile urethra is the longest (14-15 cm)

51. Female urethra
• 4cm long
• from internal urethral spincter at
bladder of neck through the
urogenital diaphragm ending at
the external urethral meatus in
the vestibule of external
genitalia
• multiple tiny urethral glands
open into the lower
urethra(homologus to the
prostate in males)

52. Spincters in female urethra
• no true spincters( prone to
incontinence)
internal urethral spincters: due to
decussation of vesicle muscle at
urethrovesical junction
involuntary muscles of urethral
wall
inner longitudinal
middle circular
outer striated(rhabdospincter)
external urethral spincter at
urogenital diaphragm ,less
developed as compared to male

53. The male reproductive organs
• consists of
prostate
seminal vesicle
testis, epididymis, vas deferens and spermatic cord
penis

54. Prostate
• it is shaped like upside down
truncated cone and surrounds the
base of the bladder and proximal
urethra, extending inferiorly to the
urogenital diaphragm and external
spincter
• it has
a base related to the bladder
above
an apex inferiorly sitting on the
pelvis (urogenital diaphragm)

55. anterior wall which is separated from the pubic symphysis by
retropubic fatty space of retzius
posterior wall related to the rectum
2 inferolateral walls related to the muscles of pelvic sidewalls

56. • fascia known as denoviller’s fasccia separates prostate and seminal
vesicle from rectum
• puboprostatic ligament provides support
• fibrous sheath derived from the pelvic fascia surrounds the prostate
gland

57. Zonal anatomy of the prostate
• peripheral
• central
• transition
for radiological purpose central
and transitional zone cannot be
distinguished so entire inner gland
is usually referred to central gland

58. transrectal usg image showing
prostate gland

59. Seminal vesicle
• paired sacculated divertiicula
that lie transversely behind the
prostate and store seminal fluid
• these convulated tube narrow at
their lower end to fuse with the
vas deference to become
ejaculatory duct.

60. Blood supply of prostate and seminal vesicle
• arterial supply:
from internal iliac arteries via inferior vesicle artery
• venous drainage
via prostatic venous plexus
prostatic venous plexuses communicates with the internal vertebral
venous plexuses providing a potential route for spread of prostatic
cancer

61. lymphatic drainage
• accompany blood vessels to internal illiac and sacral nodes

62. The testis, epididymis and spermatic cord
The testis
• oval sperm producing gland
having upper and lower pole
• size: adult dimension
approximately 5*3*2cm
• suspended by spermatic cord in
scrotal sac
• covered by fibrous capsule called
the tunica albuginea

63. • tunica is thickened posteiorly and
forms a fibrous septa known as
mediastinum testis
• fibrous septa divides the testis
into lobules
• 200-400 lobules contain sperm
producing cells which are drained
by seminiferous tubules
• seminiferous tubules converge
into mediastinium testis forming
20-30 larger ducts

64. • larger ducts forms a network of
channel within the stroma known
as rete testis
• from here 10-15 efferent ductules
convey sperm to the head of
epididymis
• testis and epididymis are
invaginated anteiorly into double
layered serous covering, the tunica
vaginalis
• tunica vaginalis is continuous with
peritoneum during development
via the processus vaginalis which is
obliterated at birth

65. Blood supply
• artery: via testicular artery
which arises directly frrom the
aorta below the level of renal
arteries
• venous drainage: via
pampiniform plexus
• lymphatic drainage: para-aortic
nodes

66. The Epididymis
• convulated sperm duct
intimately related to testis
having
 head: lying on upper pole of
testis
body: along posterolateral
aspect of testis
tail: lying inferiorly

67. The Vas Deferens
• sperm duct extends from tail of
the epididymis through scrotum,
inguinal canal and pelvis to fuse
with the duct of seminal vesicles
to form ejaculatory duct in
prostate gland

68. Spermatic cord
• it is the bundle of
nerves, duct and
blood vessels
connecting testicles
to the abdominal
cavity

69. Contents
• 3 arteries
testicular artery
artery to ductus deferens
cremasteric artery
• 3 nerves
genital branch of genitofemoral
cremasteric
autonoic nerves
• 3 other structures
ductus deferens
pampiniform plexus
lymphatics

70. The penis
• comprises of 3 cylinders of
endothelium lined erectile tissue
arising from the perineum
a ventral corpus spongiosum
surrounding urethra
paired dorsal corpora cavernosa

71. Blood supply
• arteries
via paired deep dorsal and
cavernosal artery arising from
pudendal artery
• venous drainage
via paired dorsal vein

72. The female reproductive tract
• Consists of
Vagina
Uterus
Uterine tubes
Ovaries

73. Vagina
• it is a musular canal extending from uterus to the vestibule
• the cervix invaginates the upper vagina and arbitarily divides it into
shallow anterior, deep posterior and lateral recesses or fornices

74. Blood supply
• arterial supply: via vaginal
branch of internal iliac and
uterine artery
• venous drainage: via plexus in
lateral wall to the internal iliac
vein
• lymphatic drainage
upper 2/3rd: via internal and
external iliac nodes
lower 1/3rd: via superficial
inguinal nodes

75. Uterus
• pear shaped muscular organ lying
between the bladder and rectum
• it has
fundus
body
cervix
• the uterine tubes open into cornua
of the uterus superolaterally
• the uterus leads to vagina via the
cervical canal
• internal os: is at upper end of the
cervical canal
• external os: at its lower end

76. Peritoneal reflections
• peritoneum covers the fundus body and
upper part of the vagina posteriorly and
reflected on anterior surface of the
rectum forming the pouch of douglas
• anteriorly peritoneum is reflected from
upper part of the body to the superior
surfae of the bladder
• on either side of the uterus the
peritoneum is reflected to the lateral
pelvic walls covering the fallopian tubes.
the folds of peritoneum so formed is
called the broad ligament

77. Ligamentous support of uterus
• these condensations of
endopelvic fascia anchor the
cervix to the walls of pelvis and
comprise of
pubocervical ligament
transverse cervical ligaments
uterosacral ligaments

78. Normal variants of uterus
• retroverted uterus
uterus axis lie in posterior plane
with the axis of cervix directed
upward and backwards.
• retroflexed uterus
cervix bears the usual relationship
with vagina but the uterus is bent
backward on the cervix

79. MR image depicting the retroverted uterus

80. The uterine tubes
lies in upper free edge of the
broad ligament and covey ova
from the ovaries to the uterus
• 4 parts
infundibulum
isthmus
ampulla
intrauterine part

81. Blood supply of uterus and uterine tubes
• arterial supply
 via uterine artery,a branch of
internal iliac runs medially in the
base of broad ligament
ascends tortuously within the
broad ligament to supply the
uterus and tubes
• venous drainage
via plexus in base of broad
ligament to internal iliac vein

82. Lymphatic drainage
• uterine fundus
para-aortic nodes
• uterine body
via broad ligament to external iliac
nodes
• cervix
external and internal iliac nodes

83. Ovaries
• paired oval organ measuring
appx. 3 x 2 x 2 cm
• oriented vertically on posterior
surface of broad ligament in
close contact with infundibulum
• surface is not covered by
peritoneum
• has tough outer layer: tunica
albuginea

84. supports of ovary
• mesovarium
attaches anterior surface of the
ovary to posterior surface of broad
ligament
• ovarian ligament
attaches lower pole of ovary to
the uterus
• suspensory ligament of ovary
attaches upper pole of ovary to
pelvic side wall

85. Blood supply and lymphatic drainage
• arterial supply via ovarian artery
arises directly from aorta at L2
• venous drainage
via right ovarian vein into ivc
via left ovarian vein into left renal
vein
• lymphatic drainage
along the ovarian vessels to
paraaortic nodes

86. References
• Anatomy for Diagnosting Imaging 3rd edition: Stephanie Ryan
• Textbook of Radiology and Imaging 7th edition: David Sutton
• www.radiopedia.org
• Various internet resources for images

87. Thank you