These notes describes menstrual cycle changes includes endocrine changes, endometrial wall changes and changes follicles inside ovary.

1. PHYSIOLOGY OF THE
MENSTRUAL CYCLE
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2. OUTLINE:
• Introduction
• Definition
• Characteristics of Normal Menstruation
• The Hypothalamic-pituitary-ovarian Axis
• Ovarian Cycle
• Uterine Cycle
• Menstrual Abnormalities
• Comfort Measures During Menstruation
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3. INTRODUCTION
• Typically, a woman of childbearing age or
reproductive age (15-45) should menstruate every
28 days or so unless pregnant or in menopause.
• Numerous things can go wrong with the normal
menstrual cycle.
• The menstrual cycle is essential for the production
of ova, and for the preparation of the uterus for
pregnancy.
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4. DEFINITION
• Menstruation is the periodic discharge of
blood, mucus and uterine cellular debris at
cyclic intervals from menarche to menopause.
• A.K.A: Period, Menses, Menstrual bleeding.
• Exception: Pregnancy, Lactation, Anovulation,
Pharmacological Interventions e.g.
contraceptive pills.
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5. CHARACTERISTICS OF N.M
1. Menarche: 10–16 years (Average: 13 years).
2. Duration: 2–7 days.
• <2 days – Hypomenorrhea
• >7 days – Menorrhagia
3. Amount: 30–80 ml.
• Uses 3 napkins/pads per day
• <30ml – Hypomenorrhea
• >80ml – Menorrhagia
4. Cycle length: 21-35 days (Average: 28 days).
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6. CHARACTERISTICS OF N.M CONT.
5. Normal menstrual blood doesn’t coagulate as
a result of secretion of fibrinolysin enzyme
(plasmin) secreted by the endometrium.
6. Menstrual molimina refers to mild symptoms
of 7-10 days before menstruation relieved
once menstruation occurs exaggerated
condition called Premenstrual Syndrome.
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7. NOTE:
• Menopause: 45 – 55 years (Average: 51
years).
• Factors such as hereditary, diet and overall
health can accelerate or delay menarche.
• Irregular menstrual cycle is when the cycle
length is <21 days or >35 days.
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8. CHARACTERISTICS OF N.M CONT.
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9. THE HYPOTHALAMIC-
PITUITARY-OVARIAN AXIS
• The phases of the MC and ovulation are
regulated by interaction between
hypothalamus, anterior pituitary and ovaries.
• The interaction involves hormones.
ENDOCRINE GLAND HORMONES
Hypothalamus Gonadotropin Releasing Hormone
Anterior Pituitary Follicle-Stimulating Hormone (FSH) and
Hormone (LH).
Ovaries Estrogen and Progesterone
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10. 10
Female HPG axis

11. PHASES OF MENSTRUAL CYCLE
• There are two main components of the
menstrual cycle, the changes that
happens in the ovaries (Ovarian Cycle)
and the variations that take place in the
uterus (Uterine Cycle).
• The ovarian cycle is divided into three
phases; Follicular, Ovulatory and Luteal.
• The uterine cycle into three phases;
Menstrual, Proliferative and Secretory.
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12. COMPONENTS OF MENSTRUAL
CYCLE
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13. 13
A. FOLLICULAR PHASE
B. OVULATOTY PHASE
C. LUTEAL PHASE
OVARIAN CYCLE

14. A. FOLLICULAR PHASE
• Follicular phase begins with menses on first day of
the menstrual cycle and ends with ovulation( Day 1
to Day 14 of 28-days cycle) .
• At the beginning of menstrual cycle, GnRH (pulsatile
manner) ➤ FSH and LH. FSH is responsible for the
recruitment and growth of several primordial follicle.
• Only one follicle on one of the ovaries reaches
maturity (Graafian follicle) which secretes estrogen.
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15. A. FOLLICULAR PHASE CONT.
• Increase in estrogen level causes:
1. Negative feedback on the pituitary to stop
FSH
2. The uterine lining (endometrium) to grow
thicker
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16. B. OVULATORY PHASE
• The estrogen peak stimulates secretion of LH,
leading to the LH peak which leads to the
follicle to burst open, releasing the mature
ovum, a process called ovulation.
• The remaining Graafian follicle forms Corpus
luteum.
• Ovulation occurs on day 14 of a 28-day cycle.
• High estrogen also suppress FSH secretion so
no further follicles grow.
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17. C. LUTEAL PHASE
• After ovulation, LH levels remain elevated and
cause the remnants of the follicle to develop into a
yellow body called the corpus luteum.
• In addition to producing estrogen, the corpus
luteum secretes a hormone called progesterone.
• When progesterone reaches a high level it inhibits
the secretion of LH leads to degeneration of the
corpus luteum (If fertilization does not take place).
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18. C. LUTEAL PHASE CONT.
• Degeneration of corpus luteum leads decrease in
estrogen and progesterone level and separation of
the endometrium (menstruation).
• Decrease in estrogen and progesterone level
stimulates the hypothalamus to secrete more
GnRH, a new cycle is started.
• If fertilization and implantation occurs, placenta
secretes human chorionic gonadotropin hormone
(hCG) which stimulates and maintain the corpus
luteum. hCG leads to positive urine pregnancy
test.
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19. 19
A. MENSTRUAK PHASE
B. PROLIFERATIVE PHASE
C. SECRETOTY PHASE
UTERINE CYCLE

20. A. MENSTRUAL PHASE
• First day of the menstrual cycle is marked by the
onset of menstruation (period).
• During the menstrual phase of the uterine cycle,
the uterine lining is shed because of low levels of
progesterone and estrogen.
• At the same time, a follicle is beginning to develop
and starts producing.
• The menstrual phase ends when the menstrual
period stops on approximately day 5.
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21. B. PROLIFERATIVE PHASE
• When estrogen levels are high enough, the
endometrium begins to regenerate.
• Estrogen stimulates blood vessels to develop.
The blood vessels in turn bring nutrients and
oxygen to the uterine lining, and it begins to
grow and become thicker.
• The proliferative phase ends with ovulation on
day 14.
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22. C. SECRETORY PHASE
• After ovulation, the corpus luteum begins to
produce progesterone.
• This hormone causes the uterine lining to become
rich in nutrients in preparation for pregnancy.
• Estrogen levels also remain high so that the lining
is maintained.
• If pregnancy doesn’t occur, the corpus luteum
gradually degenerates, and the woman enters the
ischemic phase of the menstrual cycle.
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23. C. SECRETORY PHASE
• Ischemic Phase - on days 27 and 28, estrogen
and progesterone levels fall because the corpus
luteum is no longer producing them.
• Without these hormones to maintain the blood
vessel network, the uterine lining becomes
ischemic.
• When the lining start slough, the woman has come
full cycle and is once again at day 1 of the
menstrual cycle.
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25. OTHER PHYSIOLOGICAL CHANGE
A. CERVICAL MUCUS CHANGE
B. BASAL BODY TEMPERATURE
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26. A. CERVICAL MUCUS CHANGES
• Changes in cervical mucus takes place over the
course of the menstrual cycle.
• Some women use these characteristics to help
determine when ovulation is likely to happen.
• During the menstrual phase the cervix doesn’t
produce mucus.
• As the proliferative phase begins, the cervix begins
to produce a tacky, crumbly type of mucus that is
yellow or white.
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27. A. CERVICAL MUCUS CHANGES
• As the time of ovulation becomes near, the
mucus becomes progressively clear, thin and
lubricative, with the properties of raw egg
white.
• At the peak of fertility(i.e., during ovulation), the
mucus has a distensible, stretchable called
spinbarkheit.
• After ovulation the mucus becomes scanty,
thick, and opaque.
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28. 28

29. B. BASAL BODY TEMPERATURE
• Basal body temperature (BBT or BTP) is the
lowest body temperature attained during rest
(usually during sleep).
• It is usually estimated by a temperature
measurement immediately after awakening
and before any physical activity has been
undertaken.
• Monitoring BBTs is one way of estimating the
day of ovulation
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30. 30

31. MENSTRUAL ABNORMALITIES
• Anovulation
• Dysmenorrhea
• Hypomenorrhea
• Metrorrhagia
• Oligomenorrhea
• Amenorrhea
• Polymenorrhea
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32. MENSTRUAL ABNORMALITIES
• Amenorrhea (no periods) is the absence of
uterine bleeding for more than 6 months in non-
menopausal women.
• Dysmenorrhea (painful periods) is the painful
menstruation, typically involving cramps.
• Hypomenorrhea is the regular menstruation
occurring at normal intervals, but with minimal
blood loss.
• Menorrhagia/Hypermenorrhea is the regular
menstruation occurring at normal intervals, but
with heavy blood loss.
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33. MENSTRUAL ABNORMALITIES
• Menometrorrhagia is the uterine bleeding occurring at
irregular intervals, with heavy (>80mL) or prolonged
(>7days) menstrual flow.
• Oligomenorrhea is the uterine bleeding occurring at
intervals of 35 days or longer (every five weeks or more).
• Polymenorrhea is the uterine bleeding occurring at
intervals of 21 days or less (every three weeks or less).
• Postmenopausal bleeding is the uterine bleeding that
occurs after menopause.
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34. MENSTRUAL ABNORMALITIES
• Premenstrual syndrome (PMS) is the
physical and psychological symptoms that
occur before the start of a period.
• Primary amenorrhea is absence for uterine
bleeding ever starting (at puberty).
• Secondary amenorrhea is absence of uterine
for more than 3 months after menarche.
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35. CARE AND COMFORT MEASURES
Menstrual hygiene:
1. Sanitary pads and tampons:
• Wash hands before and after giving self-
perineal care.
• Washing or wiping the perineum should be
always done from front to back.
• Reduce use of tampons by substituting
sanitary pads especially at night.
• Use tampon only for heavy menstrual flow.
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36. CARE AND COMFORT MEASURES
Menstrual hygiene:
2. Vaginal spray and douching:
• Spray should be used externally only not with pads.
• Should not be applied with broken irritated or itched
skin.
• Douching washes away the natural mucus and
upsets the vaginal ecology, thus make it liable to
infection.
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37. REFERENCES
1. Dutta, D.C. and Hiralal Konar (2016). DC Dutta’s
textbook of gynecology : including contraception.
New Delhi: Jaypee
2. Hall, J. (2015). Guyton and Hall textbook of medical
physiology. Elsevier.
3. Wikipedia Contributors (2019). Menstrual cycle.
[online] Wikipedia. Available at:
https://en.wikipedia.org/wiki/Menstrual_Cycle.
4. All Image from google.com/images
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38. THANK YOU
By Free Medicine
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