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FEMALE
REPRODUCTIVE
SYSTEM
Prof.Dr. Huda Al-Khateeb
Lec.9
The female reproductive system consists of
(1) Two ovaries
(2) Two oviducts (or uterine tubes)
(3) One uterus
(4) One vagina
(5) One external genitalia
Functions
1.produce female gametes (oocytes)
2.provide the environment for fertilization
3. hold the embryo during its complete development through
the fetal stage until birth.
4.produce steroidal sex hormones that control organs of the
reproductive system and influence other organs of the body
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Menarche: the first menstrual cycle. It occurs at 11-13 years.
then reproductive system undergoes cyclic changes in
structure and functional activity
Menopause is a variable period during which the cyclic
changes become irregular and eventually disappear. It
occurs at 45-55 years.
Reproductive life: period between menarche and menopause
In the postmenopausal period there is a slow involution of
the reproductive organs.
Although the mammary glands do not belong to the genital
system, yet they are included here because they undergo
changes directly connected to the functional state of the
reproductive system
ovaries
They are almond-shaped bodies (3 x1.5x1 cm).
Each ovary is covered by a simple cuboidal epithelium, the
germinal epithelium, continuous with the mesothelium and
overlying a layer of dense connective tissue capsule the
tunica albuginea, responsible for the whitish color of the
ovary
It consists of the cortex (stroma) a region filled with a highly
cellular connective tissue stroma and many ovarian follicles.
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The internal part is the medulla, which contains loose
connective tissue blood vessels entering the organ through
the hilum from mesenteries suspending the ovary.
Early Development of the Ovary
In the first month of embryonic life, a small population of
primordial germ cells migrates from the yolk sac to the
gonadal primordia.
In the gonads these cells divide extensively and differentiate
as oogonia.
In the third month, oogonia begin to enter the prophase of
the first meiotic division but arrest and called primary
oocytes.
Each primary oocyte becomes surrounded by flattened
supportive cells called follicular cells forming primordial
follicle.
No. of primordial follicles
In developing ovaries of a two-month embryo there are
600,000 oogonia
Five month embryo 7 million oocytes.
At birth 2 million oocytes.
At puberty the ovaries contain 300,000 oocytes.
Because generally only one oocyte resumes meiosis with
ovulation during each menstrual cycle (average duration, 28
days) and the reproductive life of a woman lasts about 30–40
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years, only about 450 oocytes are liberated from ovaries by
ovulation.
All others degenerate through atresia
Ovarian Follicles
They consist of an oocyte surrounded by one or more layers
of epithelial cells.
They are embedded in the cortex of the ovary
Types
1.Inactive – Primordial follicles
2.Growing follicles – include
Unilaminar primary follicle
Multilaminar primary follicle
Secondary (Antral) follicle
3.Mature (Graafian) follicle
(1)primordial follicles
(1)consist of a primary oocyte enveloped by a single layer of
the flattened follicular (granulosa) cells
(2)They are inactive follicles.
(3)These follicles are found in the superficial areas of the
cortex (under tunica albugenia).
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(4)The oocyte in the primordial follicle is a spherical cell
about 25 micrometer in diameter, with a large nucleus and
in the first meiotic prophase
Follicular Growth
Beginning in puberty with the release of follicle-stimulating
hormone (FSH) from the pituitary, a small group of
primordial follicles each month begins a process of follicular
growth
2)Growing follicles
(A) unilaminar primary follicles
(1) Oocyte is larger
(2) Follicular (granulosa) cells become cuboidal then
columna
(B) Multilaminar primary follicles
1.The follicular cells continue growth, forming a stratified
epithelium, termed granulosa cells
2.the follicle is surrounded by basement membrane
3.Between the oocyte and granulosa cells, a layer of
extracellular material called the zona pellucida develops,
consist of glycoprotein secreted by the oocyte. Zona
pellucida
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4. the stromal cells immediately around the follicle
differentiate to form the follicular theca.
5.This layer subsequently differentiates further as two
layers: a well-vascularized endocrine tissue, the theca
interna, and a more fibrous outer theca externa
containing smooth muscle and fibroblasts
(C)Secondary (antral) follicles
1.They move deeper in the ovarian cortex.
2.Small spaces develop within the granulosa layer as the cells
secrete follicular fluid (or liquor folliculi). This fluid
accumulates, the spaces gradually coalesce, and the
granulosa cells reorganize themselves around a larger
cavity, the antrum.
antrum formation pushes oocyte and the surrounding
granulosa cells to one side of follicle forming, the cumulus
oophorus.
The remaining granulosa cells are called membana granulos
(3) Mature (graafian) follicles
During each menstrual cycle, usually one follicle grows
much more than the others and becomes the dominant
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follicle, while many of the other follicles eventually enter
atresia.
The dominant follicle usually reaches the most developed
stage of follicular growth and may undergo ovulation
1.reaches a diameter of 20-30 mm or more prior to
ovulation,
2.large enough to protrude from the surface of the ovary
and be detected by ultrasound imaging.
3.The antrum increases greatly in size by accumulating
follicular fluid
4.the oocyte adheres to the wall of the follicle through the
cumulus oophorus of granulosa cells
5.The membrana granulosa layer becomes thinner.
6.The granulosa cells immediately around and linked to the
oocyte make up the corona radiata and accompany the
oocyte when it leaves the ovary
Folliculogenesis
It is a process by which primordial follicle grow on to
develop e a mature follicle
Follicular Atresia
It is adegenerative process of ovarian follicles at any stage of
development, including nearly mature follicles
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Although follicular atresia takes place from before birth
until a few years after menopause, it is most prominent just
after birth, when levels of maternal hormones decline
rapidly, and during both puberty and pregnancy, when
qualitative and quantitative hormonal changes occur again
Atresia of primary follicles (uni- and multi-laminar).
First – oocyte degenerate
Followed by follicular (granulosa) cells degeneration
Atresia of secondary (antral) follicles
1.starts by apoptosis (programmed cell death) and
detachment of the granulosa cells
2.macrophages invade the degenerating follicle and
phagocytose the debries
3.autolysis of the oocyte and collapse of the zona pellucida.
4.Later fibroblasts occupy the area of the follicle and
produce a collagen scar that may persist for a long time.