Genetic development and anatomy of female reproductive organs

1. Ms. Santosh Kumari

2.  Genotype of embryo 46XX or 46XY is established at
fertilization.
 At 1-6 wks it is sexually indifferent or
undifferentiated stage; that is genetically female and
male embryos are phenotypically indistinguishable.
 AT Week 7 begins phenotypic sexual differentiation.
 Week 12 female or male characteristics of external
genitalia can be recognized.
 Week 20 phenotypic differentiation is complete.

3. In utero photograph of a 56-day embryo showing continued
growth of the genital tubercle and elongation of the urethral
folds that have not yet initiated fusion. The genital swellings
remain indistinct.

4.  Both male and female embryos have two pairs of genital
ducts
 The mesonephric ducts (wolffian ducts) play an important
role in the development of the male reproductive system
 The paramesonephric ducts (mullerian ducts) have a
leading role in the development of the female
reproductive system
 Till the end of sixth week, the genital system is in an
indifferent state, when both pairs of genital ducts are
present

6.  Mullerian ducts form as buds of coelomic epithelium .
 Grows downward & lateral to corresponding wolffian
ducts.
 Turn inwards & crosses anterior to it joining its fellow
from opposite side.

7. Consists of
• Upper vertical part lateral to
wolffian duct → fallopian
tube.
 Middle horizontal part
crossing walffian duct →
remaining part of fallopian
tube.
 Lower vertical part fusing to
opposite part → uterus,
cervix, upper 1/3rd of vagina.
 In forming the uterus, the
mullerian ducts fuses from
below upwards

8. REABSORPTION OF SEPTUM
After the lower Mullerian ducts fuse, a central septum
is present, which subsequently must be reabsorbed to
form a single uterine cavity and cervix. Failure if
reabsorption between 14th and 18th week is the cause of
septate uterus.

9. VAGINA
 Develops in 3rd month of embryonic life.
 From lower end of uterovaginal canal (mullerian duct)
& urogenital sinus.
 Uterovaginal canal fuses with sinovaginal bulb
(develops from posterior aspect of urogenital sinus)
forming vaginal plate.
 Later canalizes to form vaginal canal.

11.  Upper 1/3rd develops from mullerian duct –
mesodermal.
 Lower 2/3rd develops from vaginal plate –
endodermal.
 Incomplete breakdown of the junction between the
bulbs and the urogenital sinus proper leaves the
hymeneal membrane.

13. By the fourth month:
 Each germ cell, now become known as Oogonia, is
surrounded by a single layer of epithelial cells
 The oogonia are transformed into primary oocytes as
they enter the 1st meiotic division and arrest in
prophase until puberty and beginning of ovulation.
 Around the 20th week of gestation the ovary contains
about 7 million germ cells.
 Degeneration and atresia begins around 20 weeks and
by birth approximately 2 million germ cells remain.

14.  The human female reproductive system is divided
into two :- internal genital organs and external genital
organs.
 Internal genital organs are
 Vagina
 Cervix
 Uterus
 Fallopian tubes
 ovaries

16.  The external genital organs are
 Mons pubis
 Labia majora
 Labia minora
 Clitoris
 Hymen
 Vestibular gland (Bartholin’s glands)
 Urethral orifice
 Vaginal orifice
 Perineum
 Anus

18. INTERNAL GENITAL ORGANS

19.  The vagina is a canal that joins the cervix (the lower part of
uterus) to the outside of the body. It also is known as the birth
canal. The diameter of the vagina is about 2.5 cm and the
length of vaginal wall at anterior is 7 cm and posteriorly 9 cm.
it is also looks like ‘H’ shape.
Relations with other pelvic organs, muscles, fascia and tissues
 Anterior- Upper 1/3rd is related with base of the bladder and
lower 2/3rd are with the urethra, the lower half of which is
firmly embedded with its wall.
 Posterior- upper 1/3rd is related with pouch of Douglas, middle
third with the anterior rectal wall separated by rectovaginal
septum and lower third is separated from the anal canal by the
perineal body.

20.  Lateral walls - upper 1/3rd is related with pelvis cellular tissue
at the base of broad ligament in which the ureter and the
uterine artery lie approximately 2 cm from the lateral fornices,
lower third is related with the bulbocavernosus muscles,
vestibular bulbs and bartholin’s glands.

21. Structures
 Four layers are – inner most is mucus coat which is lined by
stratified squamous epithelium without any secreting glands.
Submucous layer of loose areolar vascular tissues. Muscular
layer consisting of inner circular and outer longitudinal
muscles. Fibrous coat derived from endopelvic fascia and is
highly vascular.
Vaginal Secretion
 The vaginal pH from puberty to menopause is acidic because of
the presence of Doderlein’s bacilli which produce lactic acid
from the glycogen present in the exfoliated cells.
 pH varies with the estrogenic activity and ranges between 4 and
5.

22. Blood Supply
 Arteries involved are- cervicovaginal is the branch of the
uterine cavity. Vaginal artery- branch of anterior division of
internal iliac, middle rectal, internal pudendal.
 Veins drain into internal iliac veins and internal pudendal vein.

23. Lymphatics
 On one side the upper 1/3rd – internal iliac group, middle 1/3rd
up to hymen- internal iliac group, below hymen- superficial
inguinal group.
Nerve supply
 The vagina is supplied by sympathetic and parasympathetic
from the pelvis plexus. The lower part is supplied by the
pudendal nerve.

24.  Womb: The uterus is a hollow, pear-shaped organ that is the
home to a developing fetus.
 The uterus is mainly divided into two parts: the cervix, which
is the lower part that opens into the vagina, isthmus is also
consider as the lower part of uterus and the main body of the
uterus, called the corpus. The corpus can easily expand to hold
a developing baby.
 A channel through the cervix allows sperm to enter and
menstrual blood to exit.

26.  Corpus (5cm) is further divided into fundus and body.
 Fundus lies above the openings of the uterine tube. Its length
is about 1.5 cm.
 Body is triangular and lies between the openings of the tubes
and the isthmus. Its length is about 3.5 cm.
 The superolateral angles of the body of the uterus project
outwards from the junction of the fundus and body is called
the cornua of the uterus.

27.  Isthmus is a constricted part measuring about 0.5 cm situated
between the body and the cervix.
 Cervix is cylindrical in shape and measures about 2.5 cm. it
extends from the isthmus and ends at the external os which
opens up into the vagina after perforating its anterior walls.
 The normal length of the uterine cavity is usually 6.5-7cm
consists uterine body, isthmus and cervix.

30. Relations
 Anteriorly - Above the internal os, the body forms the
posterior wall of the uterovesical pouch. Below the internal
os, it is separated from the base of the bladder by loose
areolar tissues.
 Posteriorly - It is covered with peritoneum and forms the
anterior wall of the pouch of Douglas containing coils of
intestine.
 Laterally – The double fold of peritoneum of the broad
ligaments are attached between which the uterine artery
ascends up.

31. Structures
 Body- the wall of uterus consider three layers from
outside to inwards
 Parametrium – it is the serous coat which invests the
entire organ except on the lateral borders.
 Myometrium –it consists of thick bundles of smooth
muscle fibers held by connective tissues and are
arranged in various directions. During pregnancy, three
distinct layers can be identified -outer longitudinal,
middle interacting and the inner circular.

32.  Endometrium – the mucus lining of the cavity is called
endometrium. It consists lamina propria and surface
epithelium. The surface epithelium is a single layer of
ciliated columnar epithelium. The lamina propria
contains stromal cells, endometrial glands, vessels,
nerves. During pregnancy it will change into decidua.

33.  Cervix- the cervix is composed mainly of fibrous connective
tissues. The smooth muscle fibers average 10-15%. Only the
posterior surface has got peritoneal coat. The squamocolumnar
junction is situated at the external os.
 Secretion – the endometrial secretion is scanty and watery.
Secretion of the cervical glands is alkaline and thick, rich in
mucoprotein, fructose and sodium chloride.
Peritoneum in relation to the uterus
 Traced Anteriorly – the peritoneum covering the superior
surface of the bladder reflects over the anterior surface of the
uterus at the level of internal os. The pouch so formed is
called uterovesical pouch.

34.  Peritoneum is firmly attached to the anterior and posterior
walls of the uterus and upper one-third of the posterior
vaginal wall where it is reflected over the rectum. The
pouch so formed is called the pouch of Douglas.
 Traced Laterally- the adherent peritoneum of the anterior
and posterior walls of the uterus is continuous laterally
forming the broad ligament.
 On its superior free border fallopian tubes lies and on the
posterior border ovary attached by mesovarium. The lateral
one fourth of the free border is called infundibulopelvic
ligaments.

35. Blood Supply
 Arterial supply is from the uterine artery on the each side.
 Veins supply drain into internal iliac veins.
Lymphatics supply
 Body- drain from fundus and upper part of the uterus --- into--
-preaortic and lateral aortic groups of glands.
 Cornu – drain --- into--- superficial inguinal glands.
 Lower part of the body - drain --- into--- external iliac group.
In cervix- on each side drain into external iliac, internal iliac and
sacral group.

36. Nerve Supply
By both sympathetic and parasympathetic nerve system.
 Sympathetic components are from T5 and T6 (Motor) and T10
to L1 spinal ligaments (sensory).
 parasympathetic nerve system which consists both motor and
sensory fibers from S2,S3,S4 and ends in the ganglia of
Frankenhauser.
 The cervix is insensible to touch, heat and also when it is
grasped by any instrument. The uterus, too is insensible to
handling and even to incision over its wall.

37.  The ovaries are small, oval-shaped glands that are located on
either side of the uterus. The ovaries produce eggs and
hormones.
 It measures about 3 cm in length, 2 cm in breath and 1 cm in
thickness.

38. Relations
 Anterior border - A fold of peritoneum from the
posterior leaf of the broad ligament is attached to the
anterior border through which the ovarian vessels and
nerves enter the hilum of the gland.
 Posterior border - is free and is related to the tubal
ampulla. It is separated by the peritoneum from the
ureter and the internal iliac artery.

39.  Medial surface – is related to fimbrial part of the tube.
 Lateral surface – is in contact with the ovarian fossa on
the lateral pelvic wall.
 The fossa is related superiorly to the external iliac vein,
posteriorly to the ureter and internal iliac vessels and
laterally to the peritoneum separating the obturator
vessels and nerves.

40. Structures
 Ovary is covered by single layer of cubical cell known
as germinal epithelium. The substance of the gland
consists of outer cortex and inner medulla.
 Cortex – it consists of stromal cells which are
thickened beneath the germinal epithelium to form
tunica albuginea. During reproductive period the cortex
is studded with numerous follicular structures i.e. the
functional unit of the ovary, in various phases of their
development.

41. These are related to sex hormone production and ovulation.
The structures includes
 Primordial follicles, maturing follicles, graafian follicles
and corpus luteum. Atresia of the structures results in
formation of atretic follicles or corpus albicans.
 Medulla – it consists of loose connective tissues, few
unstriped muscles, blood vessels and nerves. There are
small collection of blood cells called “ hilus cells” which
are homologous to the interstitial cells of the testes.

42. Blood supply
 Arterial supply from the ovarian artery, a branch of the
abdominal aorta.
 Venous drainage is through pampiniform plexus, to form
the ovarian vein which drain into inferior vena cava on the
right side and left renal vein on the left side.
 Lymphatic – through ovarian vessels drain to the para aortic
lymph nodes.
 Nerve supply – Sympathetic supply comes down along the
ovarian artery from T10 segment. Ovaries are sensitive to
manual squeezing.

43. Development
 From the cortex of the undifferentiated genital ridges
by about 9th week, the primary germ cells reaching the
sites migrating from the dorsal end of yolk sac.

44.  These are narrow tubes that are attached to the upper part
of the uterus and serve as tunnels for the ova (egg cells)
to travel from the ovaries to the uterus.
 Length of the fallopian tube is about 10 cm and diameter
is about 2 cm.
 4 parts from medial to lateral - Intramural or interstitial
lying in the uterine wall and measures 1.25 cm in length
and 1 cm in diameter, isthmus is almost straight and
about 3-4 cm in length and 2 cm in diameter, ampulla is a
tortuous part and measures about 5 cm in length and ends
in infundibulum, and infundibulum measuring about 1.25
cm long with a maximum diameter of 6 mm

45.  Conception, the fertilization of an egg by a sperm, normally
occurs in the fallopian tubes at the part of ampulla. The fertilized
egg then moves to the uterus, where it implants into the lining of
the uterine wall.

46. Structures
 Serous – It consists of peritoneum on all sides except along
the line of attachment of mesosalpinx.
 Muscular – it arranged in two layers outer longitudinal and
inner circular.
 Mucous membrane has three different cell types and is
thrown into longitudinal folds.
Mucous membrane is lined by-
• Columnar ciliated epithelial cells that most predominant
near the ovarian end of the tube. It consists 25% of the
mucosal cells.

47. • Secretory columnar cells are present at the isthmic
segment and compose 60% of epithelial cells.
• Peg cell are found in between the columnar and
secretory cells . They are the variant of secretory cells.
Functions
 Transport of the gametes.
 To facilitate fertilization and survival of zygote through
its secretion.

48. Blood Supply
 Arterial supply is form the uterine and ovarian.
 Venous drainage is through the pampiniform plexus into the
ovarian veins.
Lymphatics
 The lymphatics run along the ovarian vessels to para- aortic
nodes.
Nerve Supply
 It derived from the uterine and ovarian nerves. The tube is
very much sensitive to handling.

56. •These are collectively called levator ani.