The document discusses the embryology and histology of the female pelvis. It describes the development of the paramesonephric (Mullerian) ducts and how they form the fallopian tubes, uterus, cervix, and upper vagina. The development of the ovaries, urinary system, and common congenital anomalies are also outlined. On histology, it examines the layers of the vagina, cervix, uterus, fallopian tubes, ovaries, ureters, bladder, and urethra. References are provided for further reading.

1. Female pelvis(content)
embryology and histology
Dr B.H MSUMI

2. introduction

5. Paramesonephric duct(mullerian)
• 5th
and 6th
week after oocyte fertilization,
longitudinal groove called muller groove
arises from coelomic epithelium on each side
lateral to mesonephric duct
• The edge of this groove fuse to form a canal
called a mullerian or paramesonephric duct

7. Development of ovaries
• The ovaries develop from the medial part of
genital ridge
• At about 4th
week gestation,primordial germ
cells(that give rise to ova) originate from the
primitive hindgut(yolk sac) then migrate to
the genital ridge
• Failure of its migration give rise to streak
gonads

11. • At 12th
weeks gestation,formation of the
mesentery of the ovary as the result of
projection of the ovary into the coelomic
cavity
• The ovary descends in the abdominal cavity
with the development of two ligaments
• The 1st
is the suspensory ligament attached to
the cephalic pole-infundibulopelvic ligament

12. • The other ligament is called
gubernaculum(tractor) which is attached to
the caudal end of the ovary
• Attached to the developing uterus forming the
future round ligament in its distal part ,while
its proximal part form the ovarian ligament

13. Development of fallopian tube
• The fallopian tube develop from the cranial
parts of the paramesonephric ducts,with their
cranial ends remaining open connecting the
duct with the coelomic(peritoneal) cavity and
the caudal ends communicating with the
uterine cornua

14. Development of uterus
• The uterus develop from the middle part of
the mullarian duct after their fusion and
canalization
• Failure of fusion or canalization or
disappearance of formed septum to become a
single organ give rise to many of congenital
uterine anomalies

15. Development of the vagina
• The upper ¾ to 4/5 of the vagina develops
from the fused and canalized part of the
caudal ends of the mullarian ducts
• While the lower ¼ or 1/5 formed from
urogenital sinus

16. • Note ,congenital malformation occurs when
mullerian duct fail to develop(congenital
absence of vagina) or fail to fuse(septate of
vagina) or fail to canalize(atresia of vagina)
• The caudal ends are closed by a septum which
is complete at 1st
but later become excavated
centrally to form the hymen.At least the distal
end of the vagina is formed from urogenital
sinus

17. • The urogenital fold is present in early embryo
and contain the origin of wolffian and
mullerian duct ie the primordial of both
urinary tract and genital tract
• So if there are genital tract malformation look
for associated malformation in the urinary
tract and vice versa

18. Development of urinary system
• Most of the urinary system develops from the
intermediate mesoderm(around the 4th
week) and
the caudal hindgut during embryogenesis in the
embryonic period.
• Derivatives of the intermediate mesoderm
include the nephrogenic cord and the ureteric
bud, which give rise to the kidneys and ureters,
respectively.
• The urinary bladder and proximal urethra
develop chiefly from the ventral portion of the
cloaca.

21. Congenital anomalies of urogenital
tract
• The mullerian and wolffian ducts are closely
related embryologically
• So the association between genital and
urinary system anomalies is common
• Malformation of genital tract may be
represented by,aplasia-atresia-hypoplasia-
fusion defects or duplication of accessory
organs

22. • Complete formation and differentiation of the
mullerian ducts into segments of the female
reproductive tract depend on completion of 3
phases of development as follows
i. Organogenesis
ii.Fusion
iii.Septal resorption

23. Organogenesis
• One or both mullerian ducts may not develop
fully ,resulting in abnormalities such as uterine
agenesis or hypoplasia(bilateral) or
unicornuate uterus

24. Fusion
• the process during which the lower segments
of the paired mullerian ducts fuse to form
uterus,cervix and upper vagina(lateral fusion)
• Failure fusion results to bicornuate or
didelphys uterus
• The term vertical fusion occasionally is used to
refer to fusion of the ascending sinovaginal
bulb with the descending mullerian system

25. Septal resorption
• After lower mullerian ducts fuse,a central
septum is present ,which subsequently must
be resorbed to form a single uterine cavity
and cervix
• Failure of resorption is the cause of septate
uterus

26. Mullerian duct anomalies
• Mullerian duct anomalies are categorized
most commonly into 7 classes according to
the American Fertility Society(AFS)

27. Class i(hypoplasia/agenesis)
• Uterine/cervical agenesis or hypoplasia
• The most common form is the Mayer-
Rokitansky-Kuster=Hauser syndrome
• Which is combined agenesis of the
uterus,cervix and upper portion of the vagina
• Patient have no reproductive potential

28. Class ii(unicornuate uterus)
• Complete or almost complete arrest of
development of one mullerian duct
• If the arrest is incomplete as in 90% of
patients,a rudimentary horn with or without
functioning endometrium is present
• If the rudimentary horn is obstructed it may
come to surgical attention when presenting as
enlarging pelvic mass
• Pregnancy believed to be possible

30. Class iii (didelphys uterus)
• Result from complete non-fusion of both
mullerian ducts
• The individual horns are fully developed and
almost normal in size
• Two cervices are inevitably present
• A longitudinal or transverse vaginal septum may
be noted as well
• Since each horn is almost a fully developed
uterus,patients have been known to carry
pregnancies to full term

32. Class iv(bicornuate uterus)
• Result from partial non-fusion of the
mullerian ducts
• The central myometrium may extend to the
level of internal cervical os (bicornuate
unicolis) or extend cervical os(bicornuate
bicollis)
• The latter is distinguished from didelphys
uterus because it demostrates some degree of
fusion between the two horns

33. • While in classic didelphysis uterus ,the two
horns and cervices are separated completely
• In addition the horns of the bicornuate uteri
are not fully developed typically
• They are small than those bicornuate
bicollisunicollis
• Some patients are surgical candidates for
metoplasty of didelphys uteri

35. Class v(septate uterus)
• A septate uterus results from failure of
resorption of the septum between the two
uterine horns
• The septum can be partial or complete in
which case it extends to the internal cervical
os
• Histologically the septum may be composed
of myometrium or fibrous tissue

36. • The uterine fundus is typically convex but may
be flat or slightly concave(1cm fundal cleft)
• Women with septate uterus have the highest
incidence of reproductive complications

37. • Differentiation between a septate and a
bicornuate uterus is important because
septate uteri are treated using transvaginal
hysteroscopic resection of the septum
• While if surgery is possible and/or indicated
for bicornuate uterus ,an abdominal approach
is required to perform metroplasty

40. Class vi(arcuate uterus)
• Arcuate uterus has a single uterine cavity
with the outer contour of the uterus convex
or flat
• This form is often considered a normal variant
since it is not significantly associated with
increased risks of pregnancy loss and the
other complications found in other subtypes

42. • The uterine anomaly is seen the female
offspring of as many as 15% women exposed
to DES during pregnancy
• Female fetuses who are affected have a
variety of abnormal findings that include
uterine hypoplasia and T-shaped uterine
cavity
Class vii(diethylstilbestrol related)

43. • Patients also may have abnormal transverse
ridges,hoods,stenosis of cervix and adenosis
of the vagina with increased risk of vagina
clear cell carcinoma

45. Fallopian tube anomaly
• Include aplasia,atresia,hypoplasia,accessory
horn or ostia and tubal diverticulum
• It may cause infertility or ectopic pregnancy

46. Vaginal anomalies
Longitudinal septa
• Partial or complete septa extending
antroposteriorly in the vagina results from failure
of disppearance of the fused Mullerian structure
• This may be associated with normal uterus or
duplicate uterus
• Occasionally the septum may not be in the
midline and may not communicate externally
leading to lateral pouch containing menstrual
blood

47. Transverse vagina septum
• Transverse or perforated
• Rare occurs at the junction of upper and middle
1/3 of vagina
• When there is no perforation in the septum
retention of mucoid material may occur before
puberty leading to mucocolpos
• After puberty menstrual flow becomes hidden
and accumulate in the vagina,uterus and giving
picture like imperforate hymen

49. Double or separate vagina
• Vaginal agenesis(absence)
• This could be partial or complete
• Complete vaginal agenesis may be part of
mullerian agenesis
• Here vagina is represented by small pouch
• Ovaries are normally developed
• Present usually with primary amenorhoea

50. • Treatment is usually construction of new
vagina or gradual dilatation
• A non-operative progressive larger dilators
inserted by the patient to gradually deepen
and widen the canal

51. Imperforate hymen
• The vaginal plate develops near the junction
of the lower part of the vagina and vestibule
• Canalization of this plate is generally
completed by the 6th
month of fetal life
• Failure of the final process of canalization
occurs and results in imperforate hymen
• treatment-cruciate incision of excision of
hymen

54. Abnormality of ovary
• Agenesis or complete absence
• Gonadal dysgenesis,streak gonads as in Turner
syndrome
• Failure of descent into the pelvis
• Ovotestis true hermaphrodite in which
combined ovarian and testicular tissue seen

55. Bladder exstrophy
• Bladder exstrophy, is a congenital anomality
in which part of the bladder is present outside
the body.
• It occurs due to failure of the abdominal wall
to close during fetal development and results
in protrusion of the posterior bladder wall
through the lower abdominal wall.

56. Bladder exstrophy

57. Ectopic ureter
• Ectopic ureter is an abnormally located
terminal portion of the ureter.
• Instead of the ureter opening in the bladder,
it opens in the urethra, vagina, or uterus.
• The result is constant dribbling of urine.

58. Vesicoureteric reflux
• Vesicoureteral reflux (VUR) is an abnormal
movement of urine from the bladder into
ureters and kidneys.
• It follows inadequecy of valvular mechanism
due to a congenital defect/lack of longitudinal
muscle of the intravesical ureter resulting in
an ureterovesicular junction (UVJ) anomaly.

59. Histology

60. vagina
• The mucosa:
– Non-keratinized stratified squamous epithelium
– Glycogens is deposited in the cells (estrogen)
– The mucosa is thrown into folds or rugae →allow
distended of vagina
• The submucosa
A layer of lamina propria,which is rich in elastic
fibres and does not have any gland

61. • The musculosa:
– Layer of smooth muscle,which has inner circular
and outer longitudinal layer .
• Adventitia:
– Merges with that of the bladder(anteriorly) and
rectum (posteriorly)

63. Cervix:
Endocervix:
– Is the cavity of cervix ,connect the external os with
internal os
– Is lined by tall columnar epithelium with basal nuclei and
the mucus membrane is thrown into branching crypts,
– It secrets mucous that undergo changes in response to
hormonal changes
– It is fusiform in shape and has posterior and anterior
oblique longitudinal ridges,the plicae palmatae
– They interlock like a zipper so the canal is kept closed

65. • Exocervix:
Lined by non-keratinizing stratified squamous
epithelium.
Composed of several layers divided into
basal,parabasal,intermediate and superficial
–
• Muscle layer
–outer longitudinal and inner circular

66. uterus
• The endometrium
–Single layer of columnar epithelium, tubular
glands and stroma.
–Varies during the menstrual cycle.
• The myometrium: 3 distinct layers
–The outer longitudinal layer
–The middle layer is of interlacing criss cross
muscle fibers in which lie large vessels.
(hemostasis)
–The inner circular layer (well developed over
tubal orifices and isthmus uteri)

67. uterus
Peritoneal covering or perimetrium:
• From the anterior surface of the uterus, the
peritoneum is reflected to the superior
surface of the bladder forming shallow
uterovesical pouch
• From the posterior surface of the uterus,
peritoneum is continued down it is reflected
to the anterior surface of the rectum forming
the R.V.P.
• From the lateral border of the uterus, two
layers of peritoneum of the uterus (

68. Fallopian tube
Like the wall of the uterus it is formed of 3 layers:
• The mucus membrane layer (endosalpinx):
– Forming longitudinal folds (plicae).
– The tube is lined by a single layer of columnar
epithelium, ciliated and secretory.
• The muscular layer:
– inner circular & outer longitudinal smooth muscle
layers.
• The peritoneal layer (mesosalpinx)
– Carries blood supply to the tube.
– It covers the fallopian tube except its inferior
surface.

69. ovary
• The germinal epithelium:
–Single layer of flattened cells (surface
epithelium of the ovary).
• Tunica albuginea:
–Condensed ovarian stroma beneath the
germinal epithelium (thickened in PCOD).

71. ovary (cont……)
• The ovarian cortex
– Main functional part of the ovary and surrounds the medulla .
– It contains collection of primordial follicles supported by a
stroma.
• The ovarian medulla:
– is the central core of the ovary& continuous with the hilum
– is composed of ordinary fibrous tissue.
• The hilum:
– the area of entrance and exit of vessels and nerves & the site
of attachment of the mesovarium.

72. Ureters
• The ureteric lumen is star-shaped. Like the
bladder, it is lined with transitional epithelium,
and contains layers of smooth muscle, thereby
being under autonomic control.
• There are two spiral layers of smooth muscle in
the ureter wall, an inner longitudinal and loose,
and an outer circular and tight.
• The adventitia of the ureter, like elsewhere is
composed of fibrous connective tissue, that binds
it to adjacent tissues

73. Urinary bladder
• The wall of the urinary bladder consists of three
layers, an outer adventitial layer of soft
connective tissue (which in some regions
possesses a serosal covering of peritoneum), a
smooth muscle coat (the detrusor muscle), and
an inner mucosal layer which lines the interior of
the bladder.
• The mucosa has a structure similar to that of the
ureters.
•

74. Urethra
• The wall of the female urethra consists of an
outer muscle coat and an inner mucosa, which
lines the lumen and is continuous with that of
the bladder.
• The muscle coat consists of an outer sheath of
striated muscle (external urethral sphincter or
distal sphincter mechanism) together with an
inner coat of smooth muscle fibres

75. references
• Textbook of medical embryology by
F.Fasana,pg 262-265
• Textbook of medical embryology by keith
moore,8th
ed
• DC Gutta textbook of gynaecology 6E pg 320-
335