THE FEMALE REPRODUCTIVE CYCLES
These are the rhythmic changes in the ovary and uterus
during the female fertility period (from 15 – 45 years).
These cycles occur approximately every 28 days.
They include the menstrual and ovarian cycles
OVARIAN CYCLE
- It is a regular monthly cycle occurring in the ovary
starting at puberty.
Stages of the ovarian cycle:
I- The Follicular phase:
Growth of 1ry follicle to mature follicle by FSH
II. Ovulation = Rupture of the Graffian follicle with liberation of the
secondary oocyte out of the ovary (day 14)
Factors causing ovulation
1- The sharp increase in LH from ant. pituitary.
2- Local weakness and degeneration of the ovarian surface.
3- The increased intrafollicular pressure.
4- Muscular contraction of the ovarian wall.
III. The Luteal phase (days 15 to 28):
Fate of corpus luteum
If fertilization does not occur:
corpus luteum of menstruation ---------------› corpus albicans
If fertilization occurs:
corpus luteum of pregnancy
Oocyte transport
1- sweeping movements of the fimbriae of the uterine tube.
2. In the uterine tube: the oocyte is pushed towards the uterine lumen by
contractions of the muscular wall and the action of the cilia of its mucosa .
(Fertilization takes 24 hours to occur)
In human, the fertilized ovum reaches the uterine lumen 3-4 days after
ovulation.
The Menstrual (Uterine)
Cycle
- It is the cyclic changes occurring in the
endometrium every ~28 days. (menses =
months).
- Starts at puberty till menopause.
It is under the control of ovarian hormones.
Stages
The menstrual phase (3-5 days):
- No fertilization -----> spasm in the uterine
arterioles ---- > cracks and fissures in the
spongy layer of the endometrium - --- >
shedding + haemorrhage.
- Menses occurs 14 days after ovulation.
Contents of the menstrual flow:
- Non-clotted blood
- Desquamated endometrium, cervical
mucus, vaginal cells.
II. The Follicular (Proliferative) phase (9 days)
- Occurs after the menstrual phase.
- Under control of estrogen secreted by the
Graffian follicle.
The endometrium ↑ in thickness (up to 3 mm),
epithelium  columnar,
uterine glands -- tortuous & rich of
mucin, glycogen.
III. The secretory (progestational)
phase (13 days)
- Starts 2-3 days after ovulation.
- Under the effect of progesterone of the
corpus luteum.
- Endometrium --- thick, soft, velvet in nature.
- Uterine glands --- more tortuous, full of
mucin, glycogen, and water.
- The ischemic phase: It is day 14 (day 28 of the
whole period) of the secretory phase where
estrogen and progesterone levels fall (due to
degeneration of the corpus luteum).