REPRODUCTIVE CYCLE and menstrual cycle

1. PRESENTATION
REPRODUCTIVE CYCLE
Presented by:
Ms. Garima

2.  INTRODUCTION
 HORMONES INVOLVED
 PHASES OF MENSTRUAL CYCLE
 MENOPAUSE
 SUMMARY
 CONCLUSION
 BIBLIOGRAPHY

3. MENSTRUAL CYCLE
 This is a series of events, occurring regularly
in females every 26 to 30 days throughout
the childbearing process of about 36 years.
 The average length of the menstrual cycle is
28 days.
 The cycle consists of series of changes
taking place in ovaries and uterine walls,
stimulated by changes in blood
concentration of hormones.

5. The hypothalamus secretes (LHRH)
Luteinising hormone releasing hormone which
stimulates anterior pituitary to secrete:
• FSH:- Follicle stimulating hormone which
promotes maturation of ovarian follicle and
secretion of oestrogen leading to ovulation.

6. • LH:- Luteinising hormone which triggers
ovulation stimulates the development of
corpus luteum and secretion of
progesterone.
Hypothalamus responds to change in
blood vessels of oestrogen and progesterone
.It is switched off by high levels and
stimulated when they are low.

7.  MENSTRUAL PHASE: (about 4 days)
 PROLIFERATIVE/ FOLLICULAR PHASE: (
about 10 days)
 OVULATION PHASE: (14TH day)
 SECRETORY/LUTEAL PHASE: (about 14
days )

8.  It is the beginning of menstrual cycle. It lasts
upto 4 days. When the ovum is not fertilized,
corpus luteum starts to degenerate.
 Oestrogen and Progesterone levels fall, the
functional layer of endometrium which is
dependent on high levels of these hormones
, sheds in menstruation.

9.  Menstrual flow consists of secretions from
endometrial glands, cells, blood from broken
capillaries and unfertilized ovum.
 High levels of progesterone and oestrogen inhibit
anterior pituitary, blocking the release of FSH and
LH and should pregnancy occur the rising levels
of hormones prevents the maturation and release
of another ovum.
 After degeneration of corpus luteum, however
falling levels of hormones lead to resumed
anterior pituitary activity , rising levels of FSH
and initiation of next cycle.

10.  At this stage an ovarian follicle stimulated by FSH is
growing towards maturity and producing oestrogen
which stimulates proliferation of the functional layer of
endometrium in preparation for the reception of a
fertilized ovum.
 The endometrium thickens, becoming very vascular
and rich in mucus secreting glands.
 This phase ends when ovulation occurs on 14th day
and oestrogen production declines.

11.  Immediately after ovulation cells of ovarian follicle
are stimulated by LH and develop into corpus
luteum.
 Under the influence of progesterone the
endometrium becomes oedematous and the
secretory gland produce increased amount of
watery mucous, which lubricates the vagina.
 The ovum may survive in a fertilisable form for
8hours . The sperm deposited in vagina during
intercource maybe capable for fertilizing the ovum
for 24 hours.

12.  Changes in woman’s body during ovulation are:-
cervical mucus become thin, elastic and watery.
Body temperature rises.
 If ovum is not fertilized menstruation occurs.
 If ovum is fertilized endometrium will not break
so no menstruation.
 Fertilized ovum gets embedded in the uterine
walls and produce hCG , which keeps the
corpus luteum intact .

13. Menopause usually occurs at the age
between 45-55, marking the end of
childbearing process. It is caused by changes
in sex hormones levels. The ovaries
gradually becomes less responsive to FSH
and LH and ovulation and menstrual cycle
becomes irregular eventually ceasing.

15.  A menstrual cycle includes a menstrual,
follicular, ovulation and secretory phase.
After fertilization, the ovum gets implanted in
the uterine wall. The female reproductive
cycles are managed through hormones
launched from the hypothalamus and interior
pituitary and hormones from reproductive
tissues and organs.

16.  Waugh Anne Grant Allison Ross and Wilson
Anatomy and Physiology in health and
illness . 13th edition page no. 495-96