This lecture is giving a detailed overview of the step by step development of the human reproductive system during the intrauterine life.

1. Development of the Female
Reproductive system
Dr. Sahar Hafeez – MD
drsaharhafeez@yahoo.com
2017

2. Learning Objectives
At the end of this lecture, the students should be able to;
• Discuss the process of differentiation of indifferent gonad into Ovaries and source
of origin of the elements of ovarian follicles.
• Elaborate upon the account of descent of Ovaries and formation of ‘round
ligaments of ovary & uterus’.
• Comprehend the process of formation of different regions of the female tract by
the paramesonephric/Mullerian ducts.
• Elucidate upon the formation of ‘broad ligament’
• Enumerate the common congenital malformations of Uterus
• Correlate between the development of Vagina with its common malformations .
• Discuss the formation of female external genitalia

3. • Absence of SRY gene
• No TDF
• Development of ovaries
• female duct system

4. Degeneration of the medullary sex cords & development of cortex
1. Mesonephric duct (Wolff)
2. PGC
3. Peritoneal cavity
4. Aorta
5. Mesonephric tubule
6. Degenerated gonadal cords
7. Thickened Coelomic epithelium
8. Intestine
9. Mesentery
10. Paramesonephric duct (Müller)
11. Atrophy of mesonephric
nephron

5. Formation of the Secondary Cortical cords
• The surface epithelium continues to
proliferate. In the 7th wk, it gives rise
to a second generation of ‘cortical
cords’.
• In the 4th month of IUL, these cords
split into isolated cell clusters, each
surrounding one or more primitive
germ cells.
• The primordial germ cells develop
into ‘oogonia’.
• The surrounding surface epithelial
cells form the ‘follicular cells’.

6. 1.Mesonephric duct (Wolff)
atrophying
2.Primordial follicle in the ovarian cortex
containing primary Oocyte
3.Aorta
4.Paramesonephric duct (Müller)
5.Mesonephric tubules atrophying
6.Degenerated Gonadal cords
7.Mesothelium of the ovary

7. • Number of Primary Oocytes at 20 wks of IUL
• 7 million
• Number of Primary Oocytes at Puberty
• 400,000

8. Descent of ovaries & the fate of Gubernaculum
The ovaries are also pulled down
from the lumbar region to the Pelvic
cavity.
They settle down slightly below the
level of pelvic brim.
Cranial end of Gubernaculum
attached b/w the lower pole of ovary
& side of uterus becomes the ‘round
ligament of ovary’.
While, the portion crossing the sides
of uterus till the caudal end attached
on the Labia majora becomes the
‘round ligament of uterus’

9. Development of the Uterus & Fallopian tubes
PARAMESONEPHRIC / MULLERIAN DUCTS
• Fallopian tubes
• Uterus
• Fundus
• Body
• Cervix
• Vaginal fornices

10. Parts of the Paramesonephric ducts
Initially three parts of the Paramesonephric duct
are recognizable;
• Cranial vertical part which opens with in the coelomic
cavity.
• Mid horizontal part which crosses the mesonephric duct.
• Caudal vertical part which fuses in the midline with its
partner from the opposite side.

11. Formation of the uterus (7th – 8th wks of IUL)
1a. Paramesonephric duct (Müller), 2a. Mesonephric duct (Wolff)
3a. Lower gubernaculum, 4a. Utero-vaginal canal, 5a. Urogenital sinus

12. Formation of the Fallopian tubes & Uterus
• With the descent of ovaries into the pelvic inlet, the first two
parts of the duct on each side will develop into the
Fallopian/Uterine tube.
• The caudal fused parts will become the Uterine canal.
• The fused paramesonephric ducts will give rise to the fundus,
body, and cervix of the uterus as well as the upper part of the
vagina.
• The surrounding mesenchyme will form the ‘myometrium’ &
‘perimetrium’.

13. 1b. Fallopian tube
2b. Atrophied mesonephric duct
3b. Ovarian ligament
3c. Round ligament of uterus
4b. Uterus
5b. Vagina

14. • As the 2 paramesonephric ducts fuse in the midline, a broad transverse
peritoneal fold establishes on each side, the Broad Ligament.
• Each ligament extends from the side of the uterus towards Pelvic walls .
• The Fallopian tubes are located in the upper border of each ligament & the ovary
lies behind it.
Formation of Broad Ligament of Uterus

15. Congenital malformations of the Uterus
Lack of fusion of Paramesonephric ducts in a localized area or
throughout the length results in different types of duplication of
uterus.
• Uterus didelphys results from failure of fusion of the inferior parts of
paramesonephric ducts. The uterus is entirely double and each one
enters a separate vagina .
• Uterus arcuatus is the least severe form in which there is malfusion in
the upper region of the vertical parts of paramesonephric ducts & is
represented by a slight indentation in the middle of the fundus of
uterus.
• Uterus bicornis is one of the more common anomalies in which the
malfusion involves only the superior part of the paramesonephric ducts
resulting in a double-horned uterus entering a single vagina.

16. Anomalies of Uterus

17. Development of the Vagina
(during 7th wk of IUL)
• The solid tip of fused paramesonephric ducts reaches the dilated
pelvic part of UG sinus.
• This solid part of UG sinus is known as ‘sinovaginal bulb’ or
vaginal plate
• The plate keeps on proliferating (thus increasing the distance
b/w the uterus & UG sinus).
• Four wing-like expansions of the fused paramesonephric duct
will encircle the cranial part of the vaginal plate. They will
become the ‘vaginal fornices’.

19. Canalization of the Vagina & formation of Hymen
• The central cells of the vaginal plate break down (by the process
of apoptosis) and a canal is formed which is continuous cranially
with the uterine canal.
• But, caudally it is separated from the cavity of the UG sinus by a
transverse membrane, the ‘hymen’.
• At the time of birth (perinatal period), this hymen usually ruptures
in the middle & remains as a thin fold of mucous membrane just
within the vaginal orifice.

20. Uterine canal & Vagina (at the time of birth)
2.Vaginal vestibule
3a. Uterine cavity
3b. Uterine cervix (neck)
6a. Vagina: The lower fourth out of
endoderm
6b. Vagina: The upper 3/4 out of
mesoderm
9. Hymen

21. Anomalies of the Vagina
Vaginal Atresia:
• Failure of canalization of the
vaginal plate will lead to vaginal
atresia.
Imperforated hymen:
• If the middle portion of the
hymen fails to get thin down
during the last weeks of IUL,
there would be failure of
rupture of hymen during the
time of birth resulting in an
imperforate hymen.

22. Formation of Female external genitalia
• The genital tubercle (GT)
elongates only slightly and forms
the clitoris
• The urethral folds (UF) do not fuse
and develop into Labia minora.
• The genital swellings enlarge
greatly and form the labia majora.
• The urogenital groove is open to
the surface & forms the vestibule
of vagina.

23. Function and purpose of the female reproductive system