The menstrual cycle involves changes in hormone levels over three stages. In the first stage (days 1-5), FSH increases and the endometrium breaks down, resulting in menstruation. In the second stage (days 6-14), FSH and estrogen rise, stimulating follicle development and an LH surge causes ovulation on day 14. In the final stage (days 14-28), progesterone rises, maintaining the thickened endometrium to prepare for implantation. If implantation does not occur, progesterone falls and menstruation begins again.

1. Roles of Hormones in
Menstrual Cycle .
By : Zulaikha Faudzi .

2. Puberty .
 The period which marks the beginning of
maturity in both males and females .
 Changes for females :
o Breast development
o Pubic and underarm hair
o Growth spurt and body shape change
o Vaginal discharge
o Skin ( oilier , acne )
o Perspiration ( body odor )
o Menstruation .
 Changes for males .
o Pubic hair
o Growth spurt
o Voice change

3. o Body hair ( face , underarm )
o Acne
Menstrual Cycle .
 Monthly cycle of changes that occurs in the
female body .
 Associated with ovulation and discharge of
blood .
 Each cycles : 28 days .
 It is important for : (a) To prepare the uterus
for the implantation of
a zygote .
(b) Occurrence of ovulation
(c) Occurrence of
menstruation

4. (d) To stimulate the
secretions of various
hormones .
Menstruation .
 Discharge of blood and tissues of the
endometrium when the uterine lining breaks
down during the menstrual cycle .
 Normally lasts for about 4 to 5 days .
Changes in the ovary during menstrual
cycle .
 Changes in the ovary associated with

5. development of follicles and ovulation .
 Changes in the thickness of the lining of the
uterus .
 Changes in the levels of hormones involved in
the menstrual cycle .

6. Importance of Menstrual Cycle .
 To prepare the uterus for the implantation of a
zygote .
 During the menstrual cycle , the lining of the uterus
becomes progressively thicker with more blood vessels .
This prepares the uterus for implantation of a fertilised
egg ( zygote ) .
 Occurrence of ovulation .
 Follicles in the ovary develop to become a mature
Graafian follicle .
 The secondary oocyte in the Graafian follicle is the
released from the ovary about halfway through a
menstrual cycle , approximately on the 14th day .
 The secondary oocyte is collected by the Fallopian tube
if sperms are present .

7.  Occurrence of Menstruation .
 If the secondary oocyte is not fertilised , it begins to
break down is discharged .
 The uterine lining also breaks down and sloughs off .
 The blood and the discarded tissue of uterine will be
discharged from the body through the vagina .
( Menstruation )
 To stimulate the secretions of various
hormones
 There are four types of hormones involved in the
menstrual cycle :
o Follicle stimulating hormone ( FSH )
o Luteinising hormone ( LH )
o Oestrogen
o Progesterone
Secreted by
pituitary gland
Secreted by
ovary

8. Roles of Hormones in Regulating the
Menstrual Cycle .
 Menstrual Cycle can be divided into three
stages .
I. Menstruation stage ( 1st day to 5th day )
II. Follicle development ( 6th to 14th day )
III. Corpus luteum stage ( 15th day to 28th day )
 The diagram shows the three stages of
menstrual cycle and the relationship
between hormonal levels with the
development of follicles , ovulation ,
formation of corpus luteum and changes
in thickness of the endometrium .

10.  Menstruation stage
 Progesterone level is at its lowest .
 The endometrium of the uterus breaks down and
sloughs off . The discarded tissue of endometrium
together with blood is discharged . Menstruation begins
.
 During menstruation , the pituitary gland is stimulated
to secrete Follicle Stimulating Hormones ( FSH) which
stimulates the development of follicles .
• Follicle development stage
 Primary follicle in the ovary develops into a Graafian
follicle .
 The development of follicles in the ovary stimulates the
secretion of oestrogen .
 Oestrogen repairs the uterine wall and causes the
endometrium to thicken in preparation for implantation .

11.  When the level of oestrogen increases and reaches a
particular level , it stimulates the pituitary gland to
secrete luteinising hormone ( LH ) . At the same time ,
it stops the pituitary gland from producing FSH causing
the of FSH become lower .
 LH causes ovulation on the 14th day . A secondary
oocyte is released from the Graafian follicle .
 Corpus luteum stage
 The Graafian follicle that remains in the ovary after
ovulation will form a corpus luteum .
 The remaining follicle cells in the ovary continue to
release oestrogen . This causes a slight increase in the
oestrogen level after ovulation . The corpus luteum
secretes progesterone .
 Progesterone thickens the endometrium and stimulates
more blood vessels to develop in it . The thick
endometrium is ready for implantation of fertilised egg .

12.  If fertilisation occurs .
 The corpus luteum remains and continues to secrete
progesterone that will maintain the thickness of the
endometrium .
 Progesterone also inhibits the secretion of FSH and LH ,
thus preventing further development of follicles and
ovulation during pregnancy .
 If fertilisation does not occur .
 The corpus luteum will degenerate .
 Progesterone level and oestrogen level become lower .
 The endometrium of the uterus begins to to break
down slough off , resulting in menstruation .

14. Effects of Hormonal Imbalances in
the Menstrual Cycle on Woman .
 Premenstrual Syndrome ( PMS )
 A combination of physical and emotional symptoms
that are related to the menstrual cycle .
 Occurs in the week before menstruation starts .
 May effect woman emotionally , mentally and
physically .
o Irritability
o Tension
o Depression
o Confusion
o Anxiety
o Oversensitivity
o Mood swings
o Low self-esteem
o Lack of concentration
Common emotional
and mental symptoms

15. o Headaches
o Fatigue
o Feeling bloated
o Breast tenderness
o Abdominal pain
o Sleep disturbances
o Appetite changes
 Miscarriage
 Progesterone maintains the thickness of the
endometrium for implantation of a zygote.
 Failure in the production of progesterone cause the
thickness of the endometrium to be reduced .
 The embryo cannot be embedded securely in the
endometrium .
 Miscarriage occurs .
Physical symptoms

16.  Menopause
 Occur between the ages of 45 and 55 .
 The ovary becomes inactive and stops producing ovum .
 Less FSH and LH is produced .
 The ovaries produce less progesterone and oestrogen
due to the limited development of follicles .
 Ovulation and the menstrual cycle become irregular and
finally stop .
 A woman is said to have reached menopause when she
has not had menstruation for 12 months in a row .
o Hot flushes
o Night sweats
o Sleeping disorders
o Osteoporosis
o Mood changes
o Weight gain
o Hair loss
Symptoms woman may
experience due to the
changes in hormone levels

17. Summary .
 Day 1-5
 Hormone : Follicle stimulating hormone ( FSH )
 Hormone level : FSH increase .
 Follicle development : FSH develops the
development of one primary
oocyte .
 Thickness of endometrium : Endometrium of
uterus breaks down .
 Day 6-14
 Hormone : (i) FSH
(ii) Oestrogen
(iii) Luteininsing hormone ( LH )

18.  Hormone level : (i) FSH continues to increase until
the 6th day and then stops .
(ii) FSH stimulates the ovary to
secrete oestrogen . The level
oestrogen increases until 12th
day . The high level of oestrogen
stimulates the secretion of LH .
(iii) The level of LH begins to
increase on the 10th day until
the 14th day .
 Follicle development : (i) The follicle continues to
develop until it becomes a
matured Graafian follicle .

19.  Follicle development : (ii) The matured Graafian
follicle bursts on the 14th
day and releases the
secondary oocyte . The
remaining Graafian follicle in
the ovary becomes the
corpus luteum .
 Thickness of endometrium : Oestrogen repairs and the
thickens the endometrium .
 Day 14-28
 Hormone : Progesterone .

20.  Hormone level : The level of progesterone begins to
increase on the 14th day until the
25th day . Then it begins to decrease
as progesterone inhibits the
secretion of FSH and LH .
 Follicle development : Corpus luteum remains but
begins to degenerate on the
25th day if fertilisation does
not occur .
 The thickness of endometrium : Maintained until
the 25th day if
fertilisation does
not occur .