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REPRODUCTIVE
ENDOCRINOLOGY
Dr Stéphane Berneau
Lecturer in Physiology and
Pharmacology
M107A
PART. 1
sberneau@uclan.ac.uk
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FEMALE REPRODUCTIVE
BIOLOGY
Describe the female reproductive axis
Describe the stages of follicular growth
during the menstrual cycle
Describe the role of hormones involved
in the female reproductive axis.
Explain the concept of positive and
negative feedback
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Mons pubis secretion of pheromones (sexual attraction)
Labia majora role of protection and lubricating secretion
Labia minora rich in blood vessel, sensitive to stimulation
Clitoris very sensitive to sexual stimulation and can erect
Bartholin’s glands secretion of thick fluid for lubrication during intercourse
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Fertilized egg (or zygote) moves into the uterus
Fallopian tube
Oocyte
Fertilization occurs in fallopian tubes
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Uterus (Fundus)
Fallopian tube
Ovary
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 Differentiation of the ovum into a cell competent
to further develop when fertilized.
Prenatal
Follicular atresia
 Occurs in the ovary
 Primary oocytes (primordial follicles):
Childhood
 1-2 millions at birth
 300,000 to 400,000 at puberty
 10% will be release during the reproductive life
Adulthood
(until menopause)
 Atresia = 99% of oocyte reserve
 Apoptotic cell death
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 Oogonia divide by meiosis during embryonic
development and stop
 Oocytes remain arrested until ovulation
 Meiosis is not completed until after fertilization
 Lifetime supply of developing eggs at birth
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Follicles consist of a developing oocyte surrounded by
an outer layer cells
Secondary
Follicle
Primordial
Follicle
Primary
Follicle
Early
tertiary
Follicle
Tertiary Follicle
Graafian Follicle
Medcell.med.yale.edu
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Histology Guide © Faculty of Biological Sciences,
University of Leeds
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GnRH: Gonadotrophin-Releasing Hormone
LH: Luteinizing Hormone
FSH: Follicle-Stimulating Hormone
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Ovulation
Follicular Phase
1th – 14th day
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recruitment
selection
Luteal Phase
14th – 28th day
dominance
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 All follicles are in competition with each other for FSH (Follicle-Stimulating Hormone).
 In response to FSH, follicular cells synthesise oestrogen which feed back to the
hypothalamus.
 Only one or two leading follicles will form graafian follicles.
 As negative feedback is exerted, the other developing follicles undergo atresia.
Once ovulation has occurred, the Graafian follicle turns into the corpus luteum and
secretes progesterone.
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Ovulation
Follicular Phase
1th – 14th day
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recruitment
selection
Luteal Phase
14th – 28th day
dominance
Window of
Implantation
Menstruation
0 – 4th day
Proliferative
4th – 14th day
Secretory
14th – 28th day
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 Essential to ovulation
 Result of prolonged exposure of hypothalamus to high levels of oestrogen from the
follicles
 Anterior pituitary switches from FSH to LH secretion
 Usually occurs in the morning
 Ovulation occurs about some hours later
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Following ovulation, the remaining follicular tissue
transforms into the corpus luteum
Responsible for production of large quantities of
progesterone, as well as some oestrogen
Progesterone maintains the uterine lining for embryo
implantation
Progesterone and oestrogen exert negative feedback;
gonadotrophin secretion is strongly suppressed
=> No further follicular growth
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1) Fertilisation- corpus luteum is
maintained by a hormone secreted by
the embryo after implantation (human
Chorionic Gonadotropin: hCG).
2) No fertilisation (or failure of
implantation)- corpus luteum dies
after approx. two weeks. Progesterone
and oestrogen levels fall, anterior
pituitary escapes from the negative
feedback.
 Results in increase in gonadotrophin
levels and the start of the follicular
phase of the next cycle.
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 Which hormone stimulates follicular growth?
 Which hormone causes ovulation?
 Which cells of the follicle make oestrogen and progesterone?
 What is the name of the follicle that is most mature?
 What happens to the other developing follicles?
 What does the follicle become after ovulation?
 Where does fertilisation occur?
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Oogenesis:
 Variation in ovarian follicle density during human fetal
development (doi: 10.1007/s10815-012-9810-2)
Folliculogenesis
 http://medcell.med.yale.edu/histology/ovary_follicle.
php
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