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 transport1 -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) The Menstrual (Uterine) CycleCycle

- - It is the cyclic changes occurring in the It is the cyclic changes occurring in the endometrium every ~28 days. (menses = endometrium every ~28 days. (menses = months).months).

- Starts at puberty till menopause.- Starts at puberty till menopause.

It is under the control of ovarian hormones.It is under the control of ovarian hormones.

Stages

The menstrual phase (3-5 days):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)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) III. The secretory (progestational) phase (13 days)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).