Asian American Pacific Islander Month DDSD 2024.pptx
The female reproductive cycle PART 8
1. Ms.Anu Sebastian: B.Pharm; M.Pharm
Assistant Professor,
Dept. Of Pharmacology
Nirmala College Of Pharmacy
Muvattupuzha,Ernakulam,Kerala
2. The female reproductive cycle includes ovarian cycle,
uterine cycles,hormonal changes regulating these cycles &
the cyclical changes in the breast and cervix.
Ovarian cycle: It is a series of events in the ovaries that
occur during & after the maturation of an oocyte.
Uterine cycle: In association with ovarian cycle the
concurrent series of changes in the endometrium of the
uterus to prepare it for the arrival of a fertilized ovum that
will develop there until birth
3. Phases of Female Reproductive cycle
The duration of female reproductive cycle ranges from
24-35 days with an average duration of 28 days.
Phases of cycle are:
Menstrual phase
Pre-ovulatory phase
Ovulation
Post ovulatory phase
4. Menstrual phase/Menstruation/Menses
It last for first 5 days of the cycle.
Events in the ovary
At 25th day onwards about 20 numbers of secondary follicles
begin to enlarge.
Follicular fluid from granulosa cells & fluid filtered from
theca folliculi capillaries accumulate in the antrum.
Events in the uterus
The progesterone level declines stimulate PGs PGs cause
contraction of arteriole Decreased blood supply to
S.functionalis cells die Shedding of this layer.
The menstrual flow (50-150ml) begins.
It includes blood,tissue fluid,mucus,epithelial cells shed from
the endometrium.
5. Preovulatory phase/Proliferative Phase/Uterine Phase
It is the time between end of menstruation & ovulation.
The length of this phase may vary.Usually in a 28 day cycle it lasts for 6-13
days.
Events in the ovary
20 secondary follicles continue to grow-start secreting estrogen & inhibin.
12th day onwards progesterone release begins.
One among the 20 follicles in either one of the ovary become dominant
follicle.
The dominant follicle(Estrogen & inhibin)inhibit the release of FSH –less
developed follicles undergo atresia.
6. Dominant follicle matures to graafian follicle.
The antrum in the graafian follicle enlarges & graafian follicle
becomes ready to rupture.
Due to the high LH release-estrogen release by graafian
follicle increases.
Events in the uterus
Growing follicle release estrogen stimulate mitosis in S.
basalis Formation of a new S.functionalis Thickening of
endometrium.
Development of blood vessels & endometrial glands
7. Ovulation
It takes place on the 14th day of cycle.
It is the release of secondary oocyte into the pelvic cavity.
The development & maturation of secondary oocyte takes
place about 20days.
The secondary oocyte (in meosis-II)+Zona pellucida+ corona
radiata is released.
The high estrogen increase GnRH release Increase the
release of LH & FSH
In addition to that estrogen directly stimulate ant.pituitory to
release LH all these leads to LH surge rupturing of mature
graafian follicle release of secondary oocyte taken up into
fallopian tube.
As a result of follicle rupturing ,pain 7 little blood loss.
8. Post Ovulatory Phase
It is the time between ovulation & next menstruation phase.It lasts 15-28
days of the cycle.
Events in Ovary(Luteal Phase)
After ovulation the basement membrane between theca cells & granulosa
breaks collapse of follicle+ due to small bleeding blood clot
formation corpus luteum is formed by the influence of LH.
C.luteum starts secreting estrogen,progesterone,Relaxin & inhibin
If the ovum is not fertilized the C.luteum continues its secretions for 2
weeks, then degenerates into Corpus albicans GnRH,FSH increases
new ovarian cycle begins.
9. If fertilization occurs , the C.luteum does not undergo degeneration
after 2 weeks.
8th day after fertilization the chorion of the embryo release hCG.
hCG stimulate the release of hormones from C.luteum.
Events in Uterus(secretory Phase)
The secretion of C.luteum stimulate the growth & coiling of
endometrial gland,arterioles.
Vascularization increases,endometrial thickening
If no fertilization, after 2 weeks decline in progesterone level due to
degeneration of C.luteum Menstruation
