The menstrual cycle is a 28-day cycle that involves changes in the ovaries and uterus, regulated by hormones from the hypothalamus, pituitary gland, and ovaries. It includes a follicular phase where follicles in the ovaries mature, an ovulation phase where an egg is released, and a luteal phase where the corpus luteum forms and progesterone is produced. If fertilization does not occur, progesterone and estrogen levels decrease, causing the uterus to shed its lining and result in menstruation.

1. MENSTRUATION CYCLE
MR.SHYAM BHATEWARA
LECTURER AT
INDEX NURSING COLLEGE

2. DEFINITION
 Menstrual cycle is the visible manifestation
of cyclic physiological uterine bleeding due
to shedding of endometrium & blood
outflow through the vagina followed by
invisible role of hormone, known as
menstruation cycle.

3. HPO Axis
 Hypothalamus :-
GnRH (gonadotropin releasing hormone)
 Pitutary:- Anterior pituitary called adeno-hypophysis
Gn hormone (gonadotropin hormone)
 Ovary :- oestrogen & progesterone

4. GnRH
Activate anterior
pituitary hormone
Secrete hormone
FSH & LH
These hormone
are work on ovary
And ovary release
oestrogen &
progesterone
Menstruation
cycle occur

5. IMPORTANT POINT FOR MENSTRUATION CYCLE
 Duration of cycle = 28 days
 1st menstruation cycle called menarche
 Amount of blood loss during one cycle 35 ml (20-80 ml)
 Menstrual phase = 1-7 days
 Duration of bleeding = 2-7 days (3-5 days)
 Puberty = development of secondary sexual characteristics
 age of puberty -10-16 years in female
- 12-16 years in male

6. ACCORDING TO TANNER & MARSHALL 5
STAGES OF PUBERTY
1. Breast development – Thelarche (1st sign of puberty in female)
2. Axillary hair development – Adrenarche
3. Pubic hair development –pubarche
4. Increase in hight
5. 1st menstrual cycle- menarche (last sign of puberty in female)
 Peak age of menarche – 13 years
 1st menstrual cycle mostly eggless
 Last menstrual cycle is also eggless

7. REPRODUCTIVE AGE
 Reproductive age = child bearing age
 Menarche to menopause 30 years
 15 years to 45 years
 Female ovary has 13 menses in a year
 Around 400 menses in complete reproductive life

8. NO. OF FOLLICLES
 20 weeks of female fetus – 7 million on. Of
follicles(70 lacs)
 At birth – 2 million
 Reproductive age – 4 million
 After menopause – less than 10000no. Of
follicles

9. MENSTRUAL BLOOD
 Menstrual blood is totally waste & dark red blood
in colour
contain-
 Mucus
 Dead endometrial cells
 Prostaglandins
 Micro-organisms
Menstrual does not clot because of plsmin

10. CHANGES DURING MENSTRUAL CYCLE
1. Ovarian changes –
a) Follicular phase
b) Luteal phase
2. Uterine changes-
a) Bleeding phase
b) Proliferative phase
c) Secretory phase

11. OVARIAN CHANGES
1. Follicular phase-
 It is first half of the menstrual cycle
 It also called pre-ovulatory phase
 Up to 14 days
 Immature follicles become mature in the presence of FSH
2. Luteal phase-
 15 – 28 days
 2nd half of menstrual cycle
 Post ovulatory phase
 Formation of corpus luteum
 Corpus luteum is yellow colour body formation after rapture of
graafian follicle
 Function- secretion of hormone progesterone( in large amount)
& oestrogen (in small amount )

12. UTERINE CHANGES
 Bleeding phase/ menstrual phase:- (menses, periods, catamania)
 Bleeding phase 1-5 days may up to 7 days
 At the end of the bleeding phase thickness of endometrium 1-2 mm
 Normal thickness 8-10 mm

13. If fertilization
not occur
Corpus luteum
disappear at 26-
28 dyas
Decrease
progesterone &
oestrogen
Causes
vasoconstriction
Contraction of
uterine artery
Decrease blood
supply to the
uterus
Hypoxia &
ischemia occur
Endometrial
cells dead
Shedding of
Endometrial
cells
Blood vessels
open & bleeding
from uterus
Blood & dead
cells collected in
uterus
nerve
stimulation of
uterus
Posterior
pituitary release
Oxytocin
Act on
myometrium of
uterus
Causes uterine
contraction
Blood through
the vagina

14. PROLIFERATIVE PHASE
 6-14 days
Division of the endometrium cells
Increase no of endometrial cells
Due to oestrogen hormone
Growing follicles release oestrogen hormon
Division of endometrial cells

15. SECRETARY PHASE
 Also known as preparatory phase
 15-28 days
 Secretory activity of corpus luteum
 Progesterone increase size of endometrial cells
 at this phase endometrium is prepared for next M. cycle
if fertilization not occur
 Endometrium also prepare for implantation if fertilization
occur

16. HORMONAL REGULATION OF
MENSTRUATION CYCLE
 Follicle phase – FSH
 Ovulation – LH
 Luteal phase- FSH & LH
 Bleeding phase- decrease progesterone & oestrogen
 Proliferative phase – oestrogen hormone
 Secretory phase - progesterone & oestrogen