Menstruation is the visible manifestation of Cyclic physiologic uterine bleeding due to shedding of the endometrium following invisible interplay of hormones mainly through hypothalamo-pituitary-ovarian axis.
The first Menstruation (Menarche) occurs between 11-15 years and it ceases between the ages 45-50 when Menopause sets in.
The Menstrual Cycle is divided in four phases–
- Menstruation / Menstrual phase
- Follicular phase
- Ovulatory phase
- Secretory / Luteal phase
Menstruation :-
- The duration of Menstruation (menses) is about 4-5 days.
- The amount of blood loss is estimated to be 20 to 80 ml with an average of 35 ml.
- Nearly 70 per cent of total menstrual blood loss occurs in the first 2 days.
- The menstrual discharge consists mainly of dark altered blood, mucus, vaginal epithelial cells, fragments of endometrium, prosta- glands, enzymes and bacteria.
Follicular phase :-
- It starts immediately after menstruation or menstrual phase.
- The follicle from the ovary starts developing and becomes mature by the end of follicular phase.
- The estrogen level increases during this phase.
- The follicles develop into primary, secondary and tertiary follicles, then into secondary oocyte.
- After completion of first meiotic division, it get surrounded by a layer of zona pellucida.
Ovulatory phase :-
- Ovulation is a process whereby a secondary oocyte is released from the ovary following rupture of a mature graffian follicle and becomes available for conception.
- This even occurs 14 days prior to the expected period.
- It’s causes include LH surge ( rise in Leutinising hormone level) and FSH rise.
- The FSH rise releases plasmin which help in lysis (breaking) of follicle.
Luteal / Secretory phase :-
- Corpus luteum- After ovulation, the ruptured graffian follicle develops into corpus luteum.
- This phase begins on 15th day and ceases 5-6 day prior to menstruation.
- The corpus luteum secretes large amount of progesterone which is essential for maintenance of endometrium.
- Such an endometrium is necessary for implementation of fertilized ovum.
In the absence of fertilization, corpus luteum degenerates marking a new cycle.
Best way to study a menstrual cycle =
The best way to study a menstrual cycle is the graphical representation of all the events in with respect to days, given in NCERT. If you are able to decode the graph, you can understand the cycle in one go.
*Decoding the NCERT graphical representation –
- During Menstruation or menstrual phase, the inner uterine wall breaks and you can see the wall decreasing during 1- 7 days. Hormones remain constant.
- During Follicular phase (before 14th day), you can see the development of follicle and a little rise in estrogen level.
- During Ovulatory phase (14th day), you can clearly see the rise in LH and FSH and rupture of graffian follicle. These is rise in estrogen as well.
- During Secretory phase (After 14th day), there is marked increase in progesterone level (as is secreted by corpus luteum) and decrease in progesterone level. Also you can see the endometrial growth in Uterine events.
Hence, you can draw your own graph, like we have shown above.
Wish To Read The Ayurvedic Version Of Menstrual Cycle i.e. Aartav Chakra, CLICK HERE.