The menstrual cycle is regulated by hormones from the hypothalamus, pituitary gland, and ovaries. It involves both the ovarian cycle and uterine cycle. The ovarian cycle consists of the follicular phase leading up to ovulation on day 14, and the luteal phase after. The uterine cycle involves the menstrual, proliferative, and secretory phases. Hormones like FSH, LH, estrogen, and progesterone are involved in a feedback loop to regulate the cycle. Disorders of the menstrual cycle can cause problems like painful periods or abnormal bleeding.

1. MENSTRUAL CYCLE REGULATION
Misbah Akram

2. Menstruation???
 Natural changes that occur in the uterus and ovary as
an essential part of making sexual reproduction
possible.
 Essential for the production of eggs, and for the
preparation of the uterus for pregnancy.

3.  Average length= 28
days
 Ages of 11 and 14
 Controlled by
hormones
 Interaction between
hypothalamus,
pituitary, ovaries &
uterus.
 Each cycle divided into
phases

5. Each female reproductive cycle has two
components:
 Ovarian cycle
 Uterine cycle

7. Ovarian Cycle
 Ovulation occurs at 14th day of 28-days ovarian cycle.
 14 days prior to ovulation are called follicular phase.
 While 14 days after ovulation constitute luteal phase.

8. Uterine Cycle
 Ovulation occurs at 14th day of 28-days uterine cycle.
 14 days prior to ovulation are subdivided into menstrual phase
(day 1-5) and a proliferative phase (6 -14) .
 While 14 days after ovulation constitute secretory phase.

9. In the first 5 days, GnRH stimulates anterior
pituitary to increase production of FSH and
LH.
Day 1-5: Primordial follicle matures to primary
follicles each containing a diploid primary
oocyte.
Day 6-13: Primary follicles form secondary
follicles.
After 16 hours: FSH & LH
Maturation of follicle called graafian follicle.
Just prior to ovulation, primary
oocyte complets meiosis
1 to form secondary
haploid oocyte.
Follicular Phase

10. Ovulation
• Release of secondary
oocyte from mature
follicle.
• Guided by high level of
LH.
Luteal Phase
•Days: 15-28
•Remaining ovarian follicular cells
form a yellowish structure called
corpus luteum.
•Production of progesterone and
estrogen by corpus luteum

11. Menstrual Phase
• Progesterone Shedding of endometrial
lining.
• Woman’s period.
Proliferative Phase
• Estrogen produced by follicular cells
endometrian begins to reform

13. Secretory Phase
• Days: 15-28
• Progesterone and estrogen from corpus luteum
stimulates further thickening of the
endometrium.
In case of no fertilization:
• Corpus luteum becomes corpus albicans.
• Decreased level of progesterone and estrogen
• Leads to menstruation.

15. Gonadotr
ophin
releasing
hormones
Follicle
stimulatin
g
hormones
Leuteinizi
ng
hormones
estrogen
progester
on

16. *Gonadotropin-releasing
hormone
Five hormones
involved in an
elaborate
scheme
involving both
positive and
negative
feedback
Cyclic secretion of GnRH* from the hypothalamus
And of FSH and LH from the anterior pituitary
orchestrates the female reproductive cycle

17. ROLE of GnRH IN THE MENSTRUAL CYCLE
• The hypothalamus secretes GnRH in a pulsatile fashion
• GnRH activity is first evident at puberty
• Follicular phase GnRH pulses occur hourly
• Luteal phase GnRH pulses occur every 90 minutes
• Loss of pulsatility down regulation of pituitary receptors  
secretion of gonadotropins
• Release of GnRH is modulated by –ve feedback by:
 steroids
 gonadotropins
• Release of GnRH is modulated by external neural signals

18. 1. High levels of estrogens suppress the release of GnRH (bar) providing a negative-
feedback control of hormone levels.
2. Secretion of GnRH depends on certain neurons in the hypothalamus which
express a gene (KISS-1) encoding a protein of 145 amino acids. From this are cut
several short peptides collectively called kisspeptin. These are secreted and bind
to G-protein-coupled receptors on the surface of the GnRH neurons stimulating
them to release GnRH. However, high levels of estrogen inhibit the secretion of
kisspeptin and suppress further production of those hormones.

19. Follicle
Stimulating
Hormone
(FSH)
Site of Secretion
Pituitary gland
Target Organ
Ovary
Function
stimulates the
growth &
development of the
follicle
stimulates
secretion of
oestrogen
effect of LH in
stimulating
ovulation
Oestrogen
Ovary
Endometrium
(lining of the uterus)
stimulates repair of
uterine lining
at high conc.
inhibits FSH,
however during
'pituitary hormone
surge' it stimulates
further FSH
production
as conc. peaks
stimulates release
of LH
Lutenising
Hormone (LH)
Pituitary
Ovary
stimulates the final
development of the
follicle
stimulates
ovulation
stimulates the
development of the
corpus luteum
stimulates
production of
progesterone
Progestrone
Corpus luteum
Uterus
maintains uterine
lining
endometrium)
inhibits release of
FSH
inhibits release of
LH
fall in conc. results
in menstruation
fall in conc.
removes inhibition
of FSH and a new
cycle begins.

20. Found in follicular fluid
Stimulates FSH induced
estrogen production
 gonadotropin receptors
androgen
No real stimulation of FSH
secretion in vivo (bound to
protein in serum)
Local peptide in the
follicular fluid
-ve feed back on
pituitary FSH secreation
Locally enhances LH-
induced
androstenedione
production
ACTIVINS
INHIBINS

22. Hormonal feedback control of menstrual
cycle

24. Hormones of Placenta
 The placenta forms large quantities of human chorionic gonadotropin,
estrogen, progesterone and human chorionic somatomammotropin,
which are all essential to a normal pregnancy
 HUMAN CHORIONIC GONADOTROPIN (HCG)
 HCG is a glycoprotein with a molecular weight of 39,000.
 It is secreted by the syncytial trophoblast cells and can be measured in
the blood 8 to 9 days after ovulation.
 The rate of secretion rises rapidly to reach maximum bout 10 to 12
weeks after ovulation and decreases to much lower value by 16 to 20
weeks after ovulation.
 It continues at this level for the remainder of pregnancy.

25. • This hormone is identical to LH in its effect and
therefore is able to maintain the corpus luteum
past the time when it would otherwise regress.
• The secretion of estradiol and progesterone is
thus maintained and menstruation is normally
prevented.
• Diagnosis of the early pregnancy

26. MENSTRUAL DISEASES
DYSMENORRHEA (PAINFUL CRAMPS)
MENORRHAGIA
AMENORRHEA/OLIGOMENORRHEA
PREMENSTRUAL SYNDROME

27. UTERINE FIBROIDS
ENDOMETRIOSIS
POLYCYSTIC OVARIAN SYNDROME
DYSFUNCTIONAL UTERINE
BLEEDING (DUB)

28. OTHER RISK FACTORS
INCLUDE:
 Weight.
 Smoking and Alcohol Use.
 Stress.
 Menstrual Cycles and Flow.
 Chronic Pelvic Pain
 Diet
 Too much exercise
POSSIBLE
COMPLICATIONS
 anemia
 osteoporosis
 infertility
 quality of life

29. DIAGNOSIS
 first the patient history
 blood and hormonal tests
 ultrasound
OTHER DIAGNOSTIC PROCEDURES
 Hysteroscopy
 Laparoscopy
 Endometrial Biopsy
 Dilation and Curettage (D&C)
MEDICATIONS
 Nonsteroidal Anti-inflammatory Drugs (NSAIDs)
 levonorgestrol, drospirenone, norgestrol, norethindrone, and
desogestrel.
 PROGESTINS
 Gonadotropin releasing hormone (GnRH) agonists