Female reproductive system
140
Course 5: Cells and tissues
development
Ontogenesis begins by fertilisation oocyte and sperm - zygote
Female genital system
Female reproductive system
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ovary - female gonad
oviduct
uterus
vagina
external genitalia
• integrated and regulated by
nerve and hormonal
regulation
• ovary: gametogenesis with
reducing chrosome
number/ meiosis and
cytodifferentiation to
complete their maturation
Ovary
• function: oogenesis and sex hormones secretion
Germinal cells – female – oogonia and oocyte
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primordial germinal cell – initially!- in the wall of yolk sac
migrate into the anlage of gonads – mitotic division under
control of medullary rete ovarii (from mesonephros) – till 5th
fetal month oogonia
primary oocytes – meiosis - stoped in diplotene of prophase
(during 7th month) – they are surrounded by follicular cells –
primordial follicles in the cortex
atresia – programed cell death
at time of the birth there are approximately 400 000 oocytes
together in both ovaries
Only 400 can be fertilized (will reach maturity)
Mesonefros a gonads
Indiferent stage of gonad - 6 week
Indiferent gonad: primitive sex cord
Male : seminiferous ducts
Žena : ovarian folicles
male embryo in 8 week
and 4 month
female embryo in 8 week
and 4 month
Germinal cells – female – oogonia and oocyte
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oogonia – primordial germinal cell – in the wall of yolk sac –
migrate into the anlage of gonads – mitotic division under
control of medullary rete ovarii (from mesonephros) – till 5th
fetal month
primary oocytes – meiosis - arrest in diplotene of prophase
of meiosis I (during 7th month) – they are surrounded by
follicular cells – primordial follicles in the cortex
atresia – programmed cell death/ apoptosis
at time of the birth there are approximately 400 000 oocytes
together in both ovaries
Only 400 can be fertilized (will reach maturity)
Ovary – prenatal period
histologically different in week 10
• primordial follicle - oogonia
oogonia + flattened epithelial cells
oogonia – oogonie
– primary oocyte (block in prophase of I.meiotic division, until
puberty, when the meiosis I is completed- during ovulation
• 7 000 000 oogonia – 5 month
• 700 000 oocytes – birth
• 400 000 onset of puberty
• 400 reach maturity/ ovulation
• no oogonia formation after birth!
Ovary - puberty + reproductive period
• regulated by hypothalamus-pituitary system (FSH, LH)
• ovarial cycle - growth and maturation of ovarian follicles: oocyte and
follicular cells
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primordial follicle
growing follicle - primary
growing follicle - secondary (antral, with antrum)
Graafian follicle
Ovulation
Fertilisation + : corpus luteum graviditatis (from the wall of
Graafian f., regulated by LH until 3 month, HCG, then corpus
albicans
• Fertilisation - : corpus luteum menstruationis several days,
then corpus albicans
Ovarian and menstrual cycle
Follicular phase – growth of
follicles from primordal to
mature Graafian follicle –
under control of FSH
Ovulatory phase
Luteal phase - development
of corpus luteum – luteal
cells produce steroids –
progesteron and estrogen
Ovary
Ovary
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Superficial epithelium –
simple cuboidal - „germinal“
Tunica albuginea
Cortex – follicles (primordial,
primary, secondary, Graafian)
corpus luteum, corpus
albicans
Medulla - vessels
Ovarian follicles
Primordial – squamous
follicular cells
Primary – growing –
cuboidal cells one or
more layers
Secondary – growing
with cavity
Mature Graafian follicle
Graafian (mature) follicle
Size: 15-20 mm
Oocyte is located excentrically on the wall in cummulus
oophorus. Oocyte is surrounded by zona pellucida and
corona radiata – one layer of follicular cells
Oocyte is detached and float free within antrum surrounded
by zona pellucida and corona radiata
Firts meiotic division is completed – secondary oocyte and
first polar body
Follicular cells express LH receptor
Follicular cells (corona radiata) and oocyte detail
Zona pellucida and corona radiata
Gap junctions enable communication between follicular
cells and oocyte
OMI -protein produced by follicular cells – through gap
junctiones – prevents the preterm maturation of oocyte
– completion of meiotic division
Just before ovulation, the oocyte activates itself (MPF
=cdk2 and cyclinB), and finishes the meiosis
Zona pellucida contains ZP1,ZP2 and ZP3 glycoproteins
Cortical granules from oocyte -changes in structure of ZP2
and ZP3. It prevents polyspermy, block binding of
additional sperm during fertilisation
Graafian (mature) follicle
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Zona pellucida and
corona radiata
Membrana granulosa –
cumulus oophorus
Liquor folliculi
Basement membrane Slavjansky
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Theca folliculi interna
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Theca folliculi externa
Ovulation
Ovulation
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Rupture of mature Graafian follicle -14th day of
menstrual cycle – stigma
Corpus luteum – membrana granulosa (granulosafollicular lutein cells 80%) and theca interna (thecalutein cells) – secretion of progesteron and estrogen
Vessels ivade through basement membrane
Corpus luteum menstruationis, c. luteum graviditatis
(HCG)
Corpus albicans
Differentiation of Graafian follicle into corpus
luteum
Follicular atresia
Development of 6 to 12 follicles
Degeneration of follicles (in every stage) is
called atresia
Atretic follicles are identified by thick folded
membranous material (glassy membrane),
intact zona pellucida, and remnant of
degenerated cells
Lutein phase
Basement membrane of follicle is penetrated by vessels
Follicular cells and thecal cells develop into follicular lutein
and thecal lutein cells
Follicular lutein cells - synthesis of progesteron and
estradiol after stimulation of FSH and LH receptors –
lacking enzymes for complete synthesis require the
cooperation with theca-lutein cells producing
androstenedion and progesteron (LH)
Estradiol stimulates the intake of cholesterol from blood
for progesteron synthesis within mitochondria
Hormonal control
development of follicle and synthesis of steroid hormones is
under control of FSH and LH, partially also under control
of autocrine and paracrine secretion of follicular cells
theca folliculi interna produces androstenedion – precursor
with androgen activity – follicular cells (aromatase) –
estradiol synthesis
synthesis is under control of LH and FSH (FSH receptors are
expressed by follicular cells and LH receptors expressed
on both follicular and thecal cells)
Ovarian and menstrual cycle