Transcript 08. female genital system

DIFFERENTIATION OF THE
OVARY
The ovarian development
is controlled by the X
chromosome .
The ovary can be 
differentiated starting
about the 10th week.


PRIMARY SEX CORDS
They dissociate into 
irregular cell clusters
Which extend into the
medulla where they
form the rete ovarii.
Normally, the cords 
and the rete ovarii
degenerate and
disappear.


SECONDARY (CORTICAL) SEX
CORDS
They are formed from
the proliferating
surface epithelium.
They penetrate the 
mesenchyme but they
still close to the
surface epithelium.

SECONDARY SEX CORDS
In the 4th month
(16 weeks) the
secondary sex
cords split into
isolated cell
clusters
(primordial
follicles).

PRIMORDIAL FOLLICLES
Each follicle contains
oogonium ( from the
primitive germ cells )
It is surrounded by a
single layer of
flattened cells
(follicular cells)
derived from the sex
cords.
Active mitosis of 
oogonia produces
thousands of the
primordial follicles.

PRIMORDIAL FOLLICLES
No oogonia form 
postnatally.
Before Birth: 
The oogonia 
enlarge to form the
primary oocytes.
PRIMORDIAL FOLLICLES
After birth ,the 
surface
epithelium
becomes
flattened into a
single layer.
It is separated 
from the follicles
in the cortex by a
thin tunica
albuginea.
OVARY
DESCENT OF THE OVARIES
The ovaries descend 
from the posterior
abdominal wall into
the pelvis.
The Gubernaculum is 
attached to the uterus
near the attachment
of the uterine tubes.
DESCENT OF THE OVARIES
The cranial part of the
Gubernaculum
becomes the ovarian
ligament.
The caudal part 
becomes the round
ligament of the
uterus.
The round ligament 
passes in the inguinal
canal and terminates
in the labia majora.

PARAMESONEPHRIC DUCTS
They form most of the
female genital tract.
They develop because
of the absence of
MIS.
They are formed from
longitudinal
invagination of
epithelium lateral to
the mesonephroi.



PARAMESONEPHRIC DUCTS
Cranially: 
Their funnel shaped ends 
open into the peritoneal
cavity.
Caudally : 
They run lateral to the 
mesonephric ducts.
They Cross them ventrally. 
They descend caudo
medially and approach each
other in the median plane.
They form the y- shaped 
uterovaginal primordium.
UTEROVAGINAL PRIMORDIUM
It opens in the dorsal
wall of the urogenital
sinus and produces
sinus (mullerian)
tubercle.

DERIVATIVES OF
PARAMESONEPHRIC DUCTS
1. UTERINE TUBES 
They develop from the
cranial un fused parts
of the
paramesonephric
ducts.

DERIVATIVES OF
PARAMESONEPHRIC DUCTS
2. 
UTEROVAGINAL
PRIMORDIUM
It differentiates 
into
uterus (body and 
cervix) and
superior part of
the vagina.
PARAMESONEPHRIC
REMNANTS IN (MALES)
Its cranial end 
may persist as
the appendix of
the testis
(attached to the
superior pole of
the testis).
The prostatic 
utricle is
homologus to the
vagina.
PERITONEUM
Movement of the 
paramesonephric ducts
mediocaudally shifts the
urogenital ridges to lie
in a transverse plane.
Fusion of the caudal 
ends of the ducts brings
(1) Two peritoneal 
pouches:
Rectouterine. 
Vesicouterine.
PERITONEUM
(2) Two 
peritoneal folds:
Right and Left
Broad ligaments.
STRUCTURE OF UTERUS
The endometrial 
stroma and
myometrium of the
uterus are derived
from the adjacent
splanchnic
mesenchyme.
The mesenchyme 
differentiate between
the layers of the
broad ligament to
form the
VAGINA
The vagina has a 
dual origin :
(1) upper portion 
from the
uterovaginal
priordium.
(2) lower portion 
from the urogenital
sinus.
VAGINA
The solid tip of the 
paramesonephric ducts
at the urogenital sinus
(sinus tubercle)
produce two solid
evaginations
(SinoVaginal Bulbs)
they grow out from the
pelvic part of the sinus.
VAGIN (LOWER PART)
The bulbs will 
proliferate and fuse
to form a solid
Vaginal Plate.
The Proliferation 
continues and it
increases the distance
between the
urogenital sinus and
the uterus.
VAGINAL PLATE
The central cells of
the vaginal plate
break down to
form the lumen of
the vagina.
The lining of the 
entire vagina is
from the vaginal
plate.

VAGINAL FORNICES
They are the 
wing like
expansions of
the vagina
around the end
of the uterus.
They are of 
paramesonephric
origin.
HYMEN
It is a thin plate of 
tissue that separates
the lumen of the vagina
from that of the
urogenital sinus.
It is formed from 
invagination of the
posterior wall of the
urogenital sinus due to
expansion of the
caudal end of the
vagina.
HYMEN
It usually 
ruptures during
the perinatal
period.
It remains as a
thin fold of
mucous
membrane just
within the
vaginal orifice.

URETHRAL & PARAURETHRAL
GLANDS
They grow from the 
urethra into the
surrounding
mesenchyme.
They are 
corresponding to the
prostate gland of the
male.
GREATER VESTIBULAR
(BARTHOLIN)
They are outgrowths
of the urogenital
sinus.
They are 
corresponding to the
bulbourethral glands
of the male.

REMNANTS OF MESONEPHRIC
DUCTS
They degenerate 
because of lack of
testosterone.
They are represented
by:
1. Epoophoron : 
Efferent ductules and
duct of epididymis in
male.
2. Paroophoron : 
Rudimentary tubules
closer to the uterus.

REMNANTS OF MESONEPHRIC
DUCTS
3. Duct of 
Gartner :
It lies between 
the layers of the
broad ligament.
It correspondes 
to the ductus
deferens and
ejaculatory duct
of male.