The menstrual cycle involves cyclical hormonal changes coordinated by the hypothalamus, pituitary gland, and ovaries. During the follicular phase, follicle stimulating hormone (FSH) causes follicle development in the ovaries. Near mid-cycle, luteinizing hormone (LH) triggers ovulation. After ovulation, the corpus luteum forms and secretes progesterone to thicken the uterine lining. If implantation does not occur, progesterone levels drop and menstruation begins. Estrogen and progesterone levels fluctuate monthly to regulate the development and shedding of the uterine lining, resulting in periodic menstrual bleeding.

1. MENSTRUAL
CYCLE
PREPARED BY:
MS. GIRLIE MANNPHY A. LACAMBRA RN, RM, MAN

2. Menstrual Cycle
OFemale reproductive
cycle
OPeriodic uterine
bleeding in response to
cyclical hormonal
changes

3. BODY STRUCTURES
INVOLVE IN THE
MENSTRUAL CYCLE

4. 1. Hypothalamus
2. Anterior pituitary gland
(APG)
3. Ovary
4. Uterus

5. Hormone Feedback Controls in the
Female Reproductive Cycle

6. HYPOTHALAMUS
OThe ultimate initiator of the menstrual cycle
by secreting Gonadotropin Releasing
Hormones (GnRH) that governs the PG by
hormonal pathways, w/c in turn governs
the ovary in the same manner.
OTHE GnRH are:
OA. Follicle Stimulating Hormone
Releasing Hormone (FSHRH)
OTriggered by ↓ serum estrogen level, it
stimulates the APG to release FSH

7. HYPOTHALAMUS
OB. Luteinizing Hormone Releasing
Factor (LHRF)
OTriggered by ↓ serum progesterone level
OStimulates APG to release Luteinizing
hormone (LH)

8. ANTERIOR PITUITARY GLAND (APG)
OIn response to stimulation from the
hypothalamus and ↓ serum Estrogen and
Progesterone levels, the APG releases the ffg
Gonadotropin hormones (GRH)
OA. Follicle Stimulating Hormones (FSH)
OThis is triggered by FSHRF and ↓ E level,
it stimulates the development of several
graafian follicles in the ovary and the
production of Estrogen.
OIt is inhibited by high serum estrogen level

9. ANTERIOR PITUITARY GLAND (APG)
OB. Luteinizing Hormone (LH)
OTriggered by ↓ serum
progesterone and LHFH
OIt stimulates the corpus luteum
to produce progesterone and
some estrogen.
OResponsible for ovulation

10. Ovary
OKnown as female gonad
OProduces estrogen during the first half of
the cycle and progesterone during the
second half of the cycle.
 Within the cortex of the ovary
 The follicles at the different phases of the dev’t
are found:
Primodial follicles
Graafian follicles
Corpus luteum
Corpus albicans

13. Primodial Follicles
OFormed during intrauterine
life
OMost of them regress before
birth
OImmature follicles inside the
ovary that contain immature
ova
ODuring a menstrual cycle,

14. Graafian Follicles
ODerived from the name of
Regner de Graaf, the Dutch
anatomist who 1st described it
in 1672.
OAfter puberty, several follicles
develop under the influence of
FSH
OThis developng promodial

15. Graafian Follicles
ODescribed as a blister like
structure barely visible to
the naked eye. As it
develops, the oocyte
within it matures
OSecret large amount of
estrogen and under the
influence of FSH.

16. Corpus Follicles
OAfter ovulation, the Graafian
follicles undergoes certain
changes.
OCells inside, now empty follicle
proliferate and enlarge until it
becomes a dense mass of cells
about 1 to 3 mm in diameter
that produce a yellow fluid
called lutein.

17. Corpus Follicles
OLutein fills the space that was
once occupied by the ovum
giving it a yellow coloration.
This is why the follicle is termed
corpus luteum after ovulation
w/c means yellow body
OThe primary hormone produced
is progesterone, although seret
some estrogen.

18. Corpus Follicles
OHas life span of 7-8 days only.
After which it regresses
OIf fertilization occurs, the
trophoblast cells of the zygote
secret HCG w/c prolongs the life
of corpus luteum & stimulates it
to continue producing
progesterone.

19. Corpus Follicles
ONot only secrets progesterone
durin pregnancy but also,
relaxin, activins, inhibins and
sometime oxytocin.
OProduce P until 8 - 12 wks
gestation
OIt usually regresses after 6
months

20. Corpus Albicans
OComplete regression of the
corpus luteum occurs before
menstruation, later it will be
seen as a white fibrous tissue,
called corpus albicans or
corpus albicantia.

21. Hormones of Ovaries
OEstrogen
OProgesterone

22. Estrogen
O FSH stimulates the Graafaian follicle to
produce Estrogen
O3 kinds of Estrogen:
OEstradiol
OEstrone and
OEstriol
OEstradiol is the most potent
OEstriol is the one found in urine
OE is metabolized by the liver and
excreted in the urine

23. Effects of Estrogen
Oinhibits FHS
OKnown as the “Hormone of Women”
bcoz it is the hormones that stimulates
the devt of the female 2º characteristics
OCauses mucus to be thin transparent
and highly stretchable
OStimulates the growth of ductile
structure of the breasts
OMenarche and menstruation

24. Progesterone
OLH stimulates the corpus
luteum to produce
progesterone.
OIts by product found in the
urine known as pregnanediol
OKnown as the “Hormone of
Pregnant Women”

25. Effects of Progesterone
OThermogenic effect: body
temperature drops by 0.5 to 1 º F a
day before ovulation because of
the very low progesterone level
at this time, and rises 1º F once
progesterone increase in level
ORemains elevated for the next 8-
10 days.

26. Effects of Progesterone
ORelaxes uterine muscles
OPromotes growth of the acini cells of the
breast
OCauses weight gain by promoting fluid
retention
OCauses tingling sensation and feeling
fullness in the breast
OStimulates endometrium glans to secret
mucin and glycogen in preparation for
implantation.

27. Uterus
OChanges occurs in the uterine
endometrium are due to the influence of
the ovarian hormones: E & P
O1st half of the cycle, proliferation of the
endometrial glands and blood vessels is
due to the influence of estrogen
O2nd half of the cycle, mucin and glycogen
secretion of endometrial glands is due to
influence of the progesterone.

28. Menstrual cycle & hormones
OA. Menarche
OOnset or the very 1st menstruation
OAn event that signifies the end of
puberty & the beginning of the
reproductive years of a woman
OTypically occurs bet 9-17 years old
(average age of onset 12 or 13
years)

29. MENSTRUAL CYCLE &
HORMONES
O B. Menstrual cycle
O rhythmic reproductive cycle in
females extending from the onset
of a period of uterine bleeding to
the onset of the next period of
bleeding
OMean cycle length is 28 days
ONormal range is 20 to 45 days per
cycle

30. MENSTRUAL CYCLE &
HORMONES
O B. Menstrual cycle
O the rhythmic menstrual cycles
begin at puberty and cease at
menopause
Ois a monthly pattern of ovulation
and menstruation

31. MENSTRUAL CYCLE &
HORMONES
O B. Menstrual cycle
Ois a monthly pattern of ovulation
and menstruation
OOvulation
ODischarge of a mature ovum
from the ovary

32. OMenstruation
OThe period of uterine bleed & shedding of
the endometrium & lasts an ave of 4-5 days
OOften referred to as menstrual phase,
bleeding, menses or a period
OPeriodic shedding of:
OBlood
OMucus
OEpithelial cells from uterus
Average blood loss is 30-80 mL

33. OOvaries
OProduce mature gametes &
secrete the ffg hormones:
OEstrogen
OProgesterone

34. Functions of estrogen:
OHormone of the woman
OPrimary function is the dev’t of 2° sexual
characteristics in female
OInhibits production of follicle stimulating
hormone (FSH)
OResponsible for hypertrophy of
myometrium
OResponsible for spinnbarkeit & ferning
(cervical mucus or Billing’s ovulation
method)

35. Functions of estrogen:
OSpinnbarkeit
OClear
OSlippery texture (like
uncooked egg white
OTypical of cervical
mucus during
ovulation

36. CLOUDY - CLEAR

37. CLEAR

38. CLEAR - STRETCHY

39. Spinnbarkeit Test

40. Spinnbarkeit Test

41. Functions of estrogen:
OFerning
OTest for the presence of
estrogen in the cervical
mucus
OEstrogen causes cervical
mucus to dry on a slide in a
fernlike pattern
OIn pregnancy testing, the
fern pattern does not appear

42. Functions of estrogen:
ODev’t of ductile structure of
the breast
O↑ osteoblastic activity of long
bones causing an ↑ in height
OAt 12 years old, female taller
than male
OEarly closure of epiphysis of
long bones

43. Functions of estrogen:
O↑ sexual desire in
female
O↑ vaginal lubrication
OResponsible for Na
retention therefore
causing wt. gain

44. Functions of progesterone
OHormone of the Pregnant
O1° function:
Oprepares the endometrium for
implantation of fertilized ovum
making it thick.
O2° function:
Oinhibits uterine contraction
OInhibits prod’n of Luteinizing
hormone (LH)

45. Functions of progesterone
O↓ GIT motility leading to
constipation
ODev’t of mammary gland
O↑ permeability of kidney to
lactose & dextrose causing (+) 1
sugar in urine.
O↑ basal body temperature
OMood swing of the woman

46. Systems responsible for
menstruation
O1. CNS
O2. Endocrine system
O3. Reproductive
system

47. CNS response
OHypothalamus
O Stimulates the anterior pituitary gland
“master clock of the body” (APG) by
secreting gonadotropin-releasing hormone
(GnRH)
O APG secretes 2 gonadotropins:
OFSH
Oprompts the ovary to develop ovarian
follicles
OThe developing follicles secrete
estrogen w/c feeds back to APG to
supress FSH & trigger a surge of LH
OLH
OActs w/ FSH to cause the ovulation &

48. Ovarian response
OAn oocyte grow w/in the primodial follicle
in 2 phases
O2 PHASES
O1. Follicular phase
ODays 1-14
OThe follicle matures as a result of
FSH.
O2. Luteal phase
Odays 15-22
OCorpus luteum develops from
ruptured follicle

49. Endometrial response
O4 PHASES
O 1. Menstrual phase
O Days 1-5
O Estrogen level is ↓
O Cervical mucus is scanty
O 2. Proliferation (Follicular) phase
O days 6-14
O Estrogen level is ↑
O Endometrium and myometrium thicken
O Cervical mucus changes
Note: average ovulation 14-28 days cycle

50. Endometrial response
O4 PHASES
O3. Secretory phase
O Days 14-26
O After release of the ovum, Estrogen level
drops
O Progesterone level ↑
O ↑ uterine vascularity
O4. Ischemic phase
O days 27-28
O Estrogen & progesterone levels recede
O Endometrium prepares to shed
O Menstruation begins

51. Cervix & cervical response
O Before ovulation
O Estrogen levels ↑
OCausing cervical os dilation
OAbundant liquid mucus
OHigh spinnbarkeit
OExcellent sperm penetration
O After ovulation
O Progesterone levels ↑
OResulting cervical os constriction
OScant viscous mucus
OLow spinnbarkeit
ONo ferning
OPoor sperm penetration

52. Cervix & cervical response
ODuring pregnancy
OCervical circulation (blood supply)
increases & a protective mucus plug
forms

53. Climacteric period & menopause
OClimacteric is a transitional
period during w/c ovarian fxn &
hormones prod’n decline
OMenopause refers to woman’s
last menstrual period
OAve age 51 with ave range 40-55

54. MS IS DIVIDED INTO 3
MENSTRUAL STAGES

55. MS IS DIVIDED INTO 3
MENSTRUAL STAGES
STAG
ES
DURATI
ON
CHARACTERISTICS HORMONES
FIRST
(MEN
STRU
ATION
OR
MENS
ES)
-LASTS
FOR 4-6
DAYS
-ENDOMETRIAL BLEEDING AND
FLOWING OUT THRU VAGINA
-E & P BLOOD
LEVELS ARE LOW
-FSH LEVEL IS
ELEVATED
COMBINED W/ LOW
LEVEL OF LH
SECRETION
SECO
ND
(FOLL
ICULA
R OR
PROLI
FERA
TIVE
-LASTS
8-10
DAYS
-ENDOMETIUM REGENERATES &
PROLIFERATES IN PREPARATIONS
FOR POSSIBLE IMPLANTATION &
SINGLE OVARIAN FOLLICLE
APPROACHES FULL MATURATION AS
THE CONCENTRATION OF ESTRADIOL
(THE PRINCIPAL ESTROGENIC
HORMONE) IN THE BLOOD RISES;
ESTRADIOL EXERTS AS A NEGATIVE
FEEDBACK ON FSH SECRETION AND A
POSITIVE FEEDBACK ON THE LH
SECRETION (THE LATTER HORMONE
INDUCES OVULATION; ESTRADIOL’S
EFFECTS ARE EXERTED ON THE
HYPOTHALAMIC SECRETION OF FSH-

57. MENSTRUAL DISORDER
VOCABULARY
• meno = menstrual related
• metro = time
• oligo = few
• a = without, none or lack of
• rhagia = excess or abnormal
• dys = not or pain
• rhea = flow

58. Amenorrhea
Dysmenorrhea
Metrorrhagia
Menorrhagia
Polymenorrhea
Hypomenorrhea
hypermenorrhea