The Menstrual Cycle
reproductive phase of a women’s life begins at puberty until menopause and it
is associated with regular menstrual flow. The onset of the first menstrual
period marks sexual maturity and is known as menache. It signals the
beginning of series of periodically recurrent changes in the hormonal status of
the female, which causes build up and shedding of the endometrium Menache
usually occurs between the ages 10 -16. Menstruation occurs once a month,
averagely it is taken to be every 28 days and recurs regularly from puberty
until menopause, though the length may vary with individuals, counting from day
1 of the menses. The flow last about 3-5 days with approximately 50 -100mls of
blood. Menstruation is in two cycles.
the follicular phase, FSH stimulate the primodial follicles in the ovary, which
respond by secreting oestrogen. (This prepares the uterine lining for arrival
and implantation of the ovum).
ovarian cortex contains about 200,000 primordial follicles at birth. The later
become graafian follides. From puberty onwards certain follicles enlarge and
one matures each month to librate an ovum.
increasing level of oestrogen signals the hypothalamus to stop producing FSH,
hence progesterone surge takes place which results in production of LH. This
enhances the maturation of the follicles which causes rupture of the follicle
on the 14th day results in ovulation.
followed by the luteal phase which begins with ovulation and ends with the
start of the menstrual flow. The ruptured follicle continue to produce LH, it
becomes, yellowish, increases in size to form the corpus Luteum (Yellow body).
Progesterone level remains high. If the ovum is not fertilized by 48 hrs the
hormonal levels drop and the endometrium begins to shed, this signals menstrual
flow. However if fertilization takes place, the corpus luteum continue to
secrete progesterone and oestrogen which maintain the endometrium until the
placenta takes over.
cycle is described in phases.
Proliferative Phase (Resting Stage)
phase begins immediately the menstruation stops. The first 2-3 days is a stage
of repair of the endometrium sometimes referred to as RegenerativePhase,
during this stage new endometrium is reformed. Proliferature phase last until
ovulation. The endometrium is ready to received ovum. It is under the control
of hormone, there is ripening of the granfian follicles which secrete oestrogen
in large quantity, under the influence of the FSH from the anterior pituitary
gland. The next level get to a peak it inhibit production of FSH. At the same
time one graafian follicle would have mature and moves to the surface of the
ovary. It bursts and discharges an ovum. This process is known as Ovulation, and takes place about
the 14 days before the next menses. As ovulation approaches, rising oestrogen
level causes the cervical mucus to become thin, clear and elastic, this
elasticity (spinnbarkheit) enhances the sperms motility and increases the
causes the endometrium to become thick, so at the end of this phase, the
structure of the endometrium consists of three layers:
layer, Functioning layer (surface layer), and Cuboidal ciliated epithelial
Secretory Phase: This follows ovulation and is
underthe influence of progesterone and oestrogen. Increase in the progesterone
level and development of corpus luteum further increases thickening of the
endometrium and become softer. The lining become more vascular and ready to
received fertilized ovum – layer increases to 3.5mm. If fertilization and
implantation occurs, progesterone level continues to increase. This inhibits
the maturation of another follicle. When the level of progesterone reaches it’s
peak and no fertilized ovum, production of LH is inhibited. The corpus luleum
degenerates and atrophies resulting in sudden drop in the progesterone level
which brings about menstrual flow as a reaction to shrinking and shedding from
the uterine wall.
Menstrual Phase: This phase is characterized by
uterinebleeding and shedding of the endometrial lining. After 14 days of corpus
luteum and no fertilization result in sudden drop of progesterone and
oestrogen, the functioning layer is shed off with the epithelial layer and
expelled by the muscular contraction of the uterine muscle. This tissues plus
bleeding from the ruptured blood vessels form the menstrual flow. It last for
about 3-5 days. Total blood loss 50-100 mls. The fibrinolysis present in the
blood prevents clotting.
contents of menstrual blood are endometrial lining, blood from capillaries
mucus and dead ovum. Regularity of menses depends on hormonal changes
associated with ovulation, which are under the influence of changes in the
anterior pituitary gland and some emotional factors. The life span of the ovum
is 24-48hrs. Women are in the most fertile state about 14 days before the next
menses. The secretary phase is more or less constant in length but the
proliferative and menstrual phases may vary.
women experience little or no discomfort during menstrual cycle while some
experience full blown premenstrual syndrome (PMS) which may occur several days
before the onset and last a few days after. Slight pelvic pain may accompany
ovulation, known as Mittlschemer’s
syndrome, which may be due to stretching ofthe ovarian capsule, slight
bleeding into the peritorieal cavity or peristalsis in the fallopian tubes –
char acterized by the following.
Headache, bloating, largely brought about by
relaxation of smooth muscle caused by progesterone.
Heaviness of the lower abdomen and legs.
Tenderness and swelling of the breasts nipples
fluids on the breast.
Visual disturbance, some women may become sleepy.
Impaired judgment careless mistakes especially
during secretary phase.
Increased activity of the skin
Increased amount of vaginal discharge and
Increased frequency of micturation.
Nervous tension, irritability, depression.
Craving for salty and sweet things.
Digestive disturbances e.g. epigastric discomfort,
heartburn and constipation.
reduced sodium in diet, avoidance of caffeine and stress – activities e.g.
walking, emotional support,and heat therapy, in severe cases refer (physician).