2. Definition: The visible manifestation of
cyclic physiologic uterine bleeding due to
shedding of the endometrium.
Due to invisible interplay of hormones
through hypo-thalamo-pituitary-ovarian axis.
For menstruation to occur axis should be
active , endometrium should be receptive
and outflow tract should be patent.
3. The period extending from first day of period
until the 1st day of next period.
Normal length of a cycle is between 28-32
days. Mean – 28 days.
It occurs cyclically between 21-35 days.
Menarche: First menstruation
Age of onset – 11-15 years &average is 13
years
4. Ovaries
Reproductive tract
Other targets
Steroids
Feedback
Hypothalamus
GnRH (gonadotrophin
releasing hormone)
Pituitary
LH
FSH
+ (“gonadotrophins”)
Menstruation is an
external indicator of
ovarian events
controlled by the
hypothalamic-pituitary
axis
Roles of the ovary
1. Gametes (ova)
2. Hormones
MENSTRUATION
(oestradiol,
progesterone).
5. Menstruation ceases between 45-50 years.
Duration – 4-5 days
Amount – 20-80 ml
Menstrual discharge consists of blood,
mucus,
epithelial cells, fragments of endometrium,
prostaglandins, enzymes and bacteria.
6. Menstrual cycle is divided into
1] Ovarian
2] Endometrial cycle
7. 0 4 8 12 16 20 24 28
Day 1
Menstruation
Day 1
LH
OVULATION
Days before Days after
Follicular
phase
Luteal
phase
8. Development and maturation of a follicle,
ovulation and formation of corpus luteum
and its degeneration
All these events occur in 4 weeks
1] Recruitment of group of follicles
2] Selection and maturation of dominant
follicle
3] Ovulation
4] Corpus luteum formation and
degeneration
9. Out of many primordial follicles only 20
antral follicles are developed in each cycle.
All these follicles from 2-5 mm size are
influenced by FSH.
Those follicles not influenced by FSH will
become atretic.
Oocyte of each follicle grow out of
proportion.Oocyte is surrounded by acellular
glycoprotein from follicular cells called Zona
pellucida
10. Flattened outer pregranulosa cells will
become Granulosa cells. These cells contain
FSH receptors.
11. Dominant follicle is called as Graafian
Follicle out of 30-50 follicles from many
primordial follicle.
Starts from 5-7 days
Follicle with high oestrogen and with
maximum FSH receptors in granulosa cells
will become a dominant one.
Rest of follicles will become atretic by 8th
day.
12. 0 4 8 12 16 20 24 28
LH
Day 1
Menstruation
OVULATION
Animated ovarian events
Oestradiol
1. Follicular
growth
Key events in the ovarian
cycle
17. Cumulus oophorus or Discus proligerous
anchors the ovum to to the wall of follicle
Corona radiata – radially arranged cells around
the ovum
At this stage FSH induces LH receptors in
granulosa cells of dominant follicle
LH receptor induction is essential for mid cycle
LH surge for ovulation and lutenisation of
granulosa cells to form corpus luteum and
secretion of progesterone
18. Graafian follicle measures 20 mm before
ovulation
It has following layers from outside inward
1] Theca externa
2] Theca interna
3] Membrana granulosa
4] granulosa cell layer
5] discus proligerous
6] corona radiata woth ovum inside
And 7] antrum with fluid
21. Total duration - 3 months
Upto antral stage of 1mm – 2months
Upto 5 mm stage – 2 weeks
Upto 20 mm – 2 weeks
22. Causes:
1] LH surge – secondary to sustained peak
level of estrogens in the late follicular phase.
This will cause completion of reduction
division in the oocyte and lutenisation of
granulosa cells, synthesise progesterone
andprostaglandins.
2] FSH rise- leads to plasminogen and it
helps in lysis of follicle.
23. 3] Stretching factor – Necrobiosis of wall due
to passive stretching
4] Contraction of micromuscles in theca
externa
24. Following ovulation the follicle is changed to
corpus luteum.
Ovum will be picked up by fallopian tube and
may fertilise or degenerate.
25. Life cycle is divided into 4 stages:
1] stage of proliferation
2] stage of vascularisation
3] stage of maturation and
4] stage of regression
26. Stage of Proliferation:
Granulosa cells will become polyhedral and enlarged and
with lipids –looks greyish yellow called granulosa lutein
cells
Stage of vascularisation: small capillaries grow towards
granulosa layer.
Stage of maturation:
After 1 week reaches 1-2cm and a carotene pigment will
give a yellow color
Stage of regression: on 22 -23 day regression starts.Lutein
cells become atrophic and will become white called
Corpus Albicans / if pregnancy occurs it will become
Corpus luteum of pregnancy.
27. 1] FSH induces LH receptors and LH surge
causes lutenisation of granulosa cells and
progesterone secretion.LH scretion should be
continuous for function of corpus luteum
2]17 alfa–OH–progesterone and estradiol
3] Low level of prolactin
Life span of Corpus luteum is 12-14 days.
28. 1] Progesterone
2] Oestrogen
3] Inhibin
4] Relaxin
In absence of pregnancy levels of O+P+I
decreases leading to rise in FSH and this in
turn leads to recruitment of new follicles
29. At 7- 10 weeks corpus luteum function will
be taken up by Placenta
31. 0 4 8 12 16 20 24 28
Menstruation
OVULATION
Oestradiol
causes an
increase in
thickness (the
“proliferative
phase”)
More secretion
from the glands –
hence the term
“secretory phase”
Endometria
l depth
32. 0 4 8 12 16 20 24 28
Menstruation
Characteristic “spiral
arteries”
Terminal differentiation of
stromal cells –
“decidualisation”
Optimal time for
implantation
33. Stratum Basalis:[ 1mm ]
Ocupies 1/3 of endometrium – basal arteries+
Not influenced by hormones
Regeneration occurs from it.
Functional zone:
Responds to hormones like O+P
In an ovulatory cycle four stages are seen.
34. 1] Stage of regeneration
2] Stage of Proliferation
3] Secretory phase
4] Menstrual phase
35. Stage of regeneration:
Starts before menstruation and completes after 2-3
days after periods. Measures 2mm.
Glands are lined by cubical cells
Stage of Proliferation:
Extends from 5-6th day to 14th day due to
Estrogens.Glands are tubular and perpendicular to
surface.
Epithelium is columnar with nuclei at base, stromal
cells are spindle shaped with spiral vessels upto
epithelium. Subepithelial congestion +. Measures 3-
4 mm.
36. Secretory Phase:
Effects of O+P
Oestrogen induces Progesterone receptors and
progesterone is responsible for secretory phase.
Starts at 15th day to 5-6 days prior to
menstruation.
Epithelium is more columnar and ciliated.
Glands increase in size with taller epithelium
with vacuoles formation- subnuclear
vacuolation.
37. First and earliest effect of progesterone is
appearence of subnucleolar vacuolation.It will
persist upto 21 days.
Saw toothed glandular epithelium, glands
become corkscrew shaped with marked spiralling
of vessels.
Measures 6-8 mm.
Regresssion of endometrium starts 24-48 hrs
prior to periods.
Marked spiralling of vessels and withdrawl of
hormones causes tissue hypoxia and anoxia.
38. Degeneration and casting off endometrium
due to regression of corpus luteum with fall
in level of O+P.
Degeneration is due to stasis of blood and
spasm of vessels leading to damage of vessels
with escape of blood.
Proteolytic enzymes from lysosomes causes
local damage.[ Enzymatic autodigestion ]
42. At menstruation Oestrogen and inhibin are at low levels and high
FSH.
Oestrogen increases gradually and FSH decreases and remains
static at day 5.
O+ LH and androgen increases.
Matuaration of follicle is combined effect of FSH and LH/
Peptides –Inhibin, Activin and Follistatin
Growth Facors – IGF, EGF from theca cells – modulate FSH,LH and
peptide actions.
IGF stimulates aromatase activity and progesterone synthesis.
Progesterone will increase in secretory phase until 5 days before
periods.
LH will start declining
43. It occurs after 10-12 hrs following LH surge.
It occurs after 24-36 hrs following Oestradiol
peak of 200 pg/ml
Progesterone peaks at 8th day after LH surge.
44. Datting of endometrium – Examination of
endometrium
Luteal phase defect – A discrepancy of more
than 2 days in the postovulatory phase when
endometrium is examined
A woman can have periods without ovulation.
45. 0 4 8 12 16 20 24 28
Menstruation
OVULATION
Cervical
mucus
Variable
number of
“dry” days
Production
of low
viscosity
mucus
increases
Abundant mucus -
like “raw egg white”
Thick, rubbery, high
viscosity - impenetrable
to sperm.
46. With increasing oestradiol:
1. The mucus becomes more abundant - up to
30x more and its water content increases.
2. Its pH becomes alkaline.
3. Increased elasticity – ("spinnbarkeit test")
5. “Ferning pattern” caused by the interaction of
high concentrations of salt and water with
the glycoproteins in the mucus.
Characteristic fernlike pattern as
the mucus dries on a glass slide.
47. 0 4 8 12 16 20 24 28
Menstruation
OVULATION
LH
36
36.2
36.4
36.6
36.8
37
37.2
37.4
37.6
37.8
38
A small (0.5 oC) rise in BBT
typically follows
ovulation.
Basal body temperature
48. Basal body temperature
Plasma oestradiol
Plasma progesterone
Volume of cervical mucus – and
sperm penetration
Uterine endometrium
49. a) Calendar Method - which is essentially based on
the previous menstrual history.
b) Temperature method - using a midcycle rise in
body temperature as a sign when ovulation has
occurred.
c) Cervical changes - which can be detected by
feeling the cervix and cervical mucus.
d) Hormonal methods - using over-the-counter "kits"
to assess urinary hormone levels.
There are a number of potential ways of trying to
identify the “fertile” period..: