MENSTRUAL CYCLE
The purpose of menstrual cycle is release secondary oocyte. this cycle is divided into two cycle .
1. Ovarian cycle - It characterise by ovulation
2. uterine cycle - It characterise by vaginal bleeding.
hormones of menstrual cycle
The complete process by hormones
Hypothalamic - GNRH
Pituitary - FSH/ LH
Ovarian - Estrogen and Progesterone .
1. GNRH { Gonadotropin-releasing hormone }.
GNRH stimulate gonads eg. Ovary and testis.
2. FSH { follicle stimulating hormone}
It responsible to develop mature follicle in ovary.
3. LH { Luteinizing hormone }
It responsible for ovulation and corpus luteum formation in ovary
4. Estrogen
Release from ovarian follicle and work upon uterine endometrium.
5. Progesterone
Release from ovarian corpus luteum and work upon uterine myometrium.
Phase of menstrual cycle
Ideal duration cycle is 28 day { 21 to 35 days} . it divided into three phase
1 to 5 days 1st phase
5 to 14 days 2nd phase
14 to 28 days 3rd phase
1. Phase first { menstrual or Bleeding phase }
* It characterised by vaginal bleeding .
* Normal amount of blood loss is 35 to 50 ml
* Vaginal bleeding is the result of damage of uterine endometrium.
* In every menstrual cycle functional layer of endometrium is damaged.
* Endometrium 🠞 Basel layer { 2- 4 mm }
🠞 Functional layer { 10-12mm}
* Menstrual bleeding is also refer as withdrawal bleeding associated with low hormonal level { both estrogen and progesterone}
2. Phase second { follicular or proliferative phase}
* 5 - 14 days
* This phase is characterised by presence of hormone.
* GNRH stimulate gonadal activities.
* FSH responsible to develop mature follicle known as graafian follicle
* Estrogen release from developing follicle and responsible for endometrium growth.
* estrogen also stimulate release of LH from pituitary .
* LH surge is define as presence of LH hormone for the ovulation .
- LH surge start 32 to 36 hours before ovulation and maximum at 10 to 12 hours before ovulation.
* 14th day of cycle ovulation occur { ovulation is define as release of secondary oocyte from graafian follicle.
* Ovulation is result of LH hormone activity and increase follicle size.
* After the ovulation
1. Secondary oocyte alive 12 to 24 hours if sperm is available conceive pregnancy if not available death of cell.
2. LH hormone develop corpus luteum. it is modification of graafian follicle.
3. Phase third { Luteal phase or secretory phase}
* 14 to 28 day of cycle.
* This phase is completely control by corpus luteum .
* Corpus luteum release both estrogen and progesterone.
* Progesterone is known as maintenance of pregnancy hormone , it responsible for increase myometrium bleeding, increase endometrium nutrition , inhibit uterine contraction.
* Progesterone prepare the uterus to receive fertilized ovum.
* In case of unfertilized condition negative feed back is activated and same reaction occur as present on first day.
* Pain during ovulation refer as mittelschmerz
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