Normal menstrual cycle and factors that affect when a woman experiences PMS
A woman’s monthly menstrual cycle can be a confusing and bewildering experience, full of highs and lows. Some women have cycles that are very regular, lasting about 28 days. Other women have cycles that can range from 21 to 35 days. Menstruation cycles can occur in a variety of ways. and there is no single answer to the question of what is the normal menstrual cycle.
1. What is the normal menstrual cycle
Menstruation is a monthly or bloody periodic discharge from the vagina. The appearance of menstruation in a woman indicates. that she has entered the period of childbearing age and her ovaries are capable of producing full-fledged female germ cells-eggs. that can be fertilized with the further development of pregnancy and the birth of offspring.
2. How many days should the Normal menstrual cycle last
The average normal menstrual cycle is 28 days (+/- 7 days), but it can vary from 21 to 35 days. In 5% of healthy women. fewer than four days pass between periods. and in another part of healthy women, menstruation lasts more than 8 days.
The occurrence of normal egg maturation is a crucial factor in the length of the menstrual cycle. During the year, a woman should have at least 9 menstrual cycles.
The cycle is considered normal. the duration of which is at least 14 days.
3. How the duration of the normal menstrual cycle changes with a woman's age
A cycle typically lasts 28 days. but this does not mean that this cycle duration is stable in all periods of a woman's life. The older a woman gets, the longer her cycle lasts. At the age of forty and older, a woman's cycle becomes longer. and by the age of 49, the average cycle length reaches 31-40 days.
About 20% of women of childbearing age may experience irregular menstrual cycles. The course can be shortened and prolonged under the influence of various factors.
For example
alcohol abuse and hard work associated with emotional or physical stress can shorten the menstrual cycle. In low-weight women (supermodels) engaged in intensive sports. the cycle length for girls under 21 years of age can be up to 40 days, which is the norm in most cases. The menstrual cycle in smoking women is generally stable. but the duration of bleeding is often longer than in healthy non-smokers.
4. How is the Normal menstrual cycle regulated.
Many organs and systems of the female body are involved in the process of regulating the normal menstrual cycle:
- central nervous system (cortex and subcortex).
- damage to the rigid zoo and curl,
- pituitary gland.
- the thyroid gland,
- and the adrenal glands.
- ovaries when pregnancy occurs, the placenta (baby's place) plays an important endocrine role in the cessation of menstruation. as well as the fetus' typical growth.
5. What is the role of the hypothalamus in regulating the Normal menstrual cycle
The hypothalamus is the external cortical center of the autonomic nervous system, it is located below the thalamus or thalamus. for which it got its name, and has a direct connection with the cortical structures of the brain. Under the influence of estrogen and progesterone levels in a woman's blood. it produces gonadotropin-secreting hormones (GnRH). which are responsible for the production of gonadotropins by the pituitary gland.
GnRH excretion does not occur continuously but in the form of short peaks that follow one after another at strictly defined time intervals. These periods differ between men and women: normally. in women, a burst of GnRH occurs every 15 minutes in the follicular phase of the cycle and every 45-60 minutes in the luteal phase and during pregnancy. and in males, every 90 minutes.
6. What are gonads
Gonadotropins are hormones that stimulate and regulate the functioning of the gonads - the reproductive organs. The pituitary gland generates them. a small hormonal gland located in the Cella turcica at the bony base of the skull.
7. What is the role of the pituitary gland in regulating the Normal menstrual cycle
Adenohypophysis refers to the pituitary gland's anterior lobe.. and it is in this section of the gland that hormones are produced that regulate the functioning of several organs, including the organs of the reproductive system .follitropin (follicle-stimulating hormone. FSH). and lutropin (luteinizing hormone, LH).
FSH stimulates the growth of granulocytes in the ovaries, which leads to an increase in estradiol levels. which, in turn, provokes the growth of follicles. At a certain level of estradiol. the pituitary gland begins to produce LH. which is necessary for follicle rupture - ovulation.
After ovulation, LH is involved in the regulation of the corpus luteum. which, under the influence of human chorionic gonadotropin (hCG), begins to produce progesterone. which is responsible for preparing the endometrium to accept a fertilized egg.
8. What is the role of the thyroid gland in regulating the menstrual cycle
Thyroid gland hormone production is in charge of. for ensuring the functioning of the reproductive organs in the female body in a balanced and accurate manner.
Violation of the menstrual cycle becomes one of the first symptoms that the gland does not perform its function. The menstrual cycle is a kind of barometer of the state of the thyroid gland. Therefore, in case of any violations. It is important to speak with more than just a gynecologist. but also undergo a full endocrinological examination
9. How many phases of the Normal menstrual cycle
The entire menstrual cycle can be divided into the follicular phase (the first phase), ovulation, the luteal phase (the second, or progesterone), and the bleeding period.
10. What is ovulation
Ovulation is the release of a mature egg from the ovarian follicle into the abdominal cavity. for further fertilization.
11. How many eggs are there in a woman's ovary.
The newborn girl has 7-10 million ovules-ovules. Therefore, it is important to remember that the health of the future woman is formed in the womb. From the moment of conception to the moment of puberty. and the possibility of having children. the female body loses millions of eggs that cannot be replenished. Most follicles die during the process of apoptosis (apoptosis).
At the time of the first menstruation, the girl had about 400,000 eggs. It is estimated that a woman with a regular menstrual cycle produces about 400 mature eggs (300-500 according to some sources). during her lifetime.
This does not mean that she can become pregnant 400 times.
because not all eggs are complete, and periods of life when a woman does not have open sexual contact with a man should also be excluded. At the age of forty, the process of death of oocytes accelerates. and by the age of fifty. There aren't many of them remaining at all.
But even during menopause, rudimentary follicles are located in the ovaries (formed as a result of the multiplication of primary female sex cells). which are not sensitive to high doses of gonadotropins.
12. How many days does the ripening period of one egg takes
The period of full maturation of the egg takes about 90 days, starting with the growth of a small follicle (Antrum). its development into a dominant follicle, and ending with its rupture. Interestingly, the entire period of maturation of the follicle. except for the last two weeks. is independent of gonadotropin levels.
13. What is the follicular phase of the menstrual cycle
The follicular phase of the menstrual cycle begins on the first day of menstruation and ends with the process of ovulation. With a 28-day cycle, this period lasts an average of 14 days.
During the first two weeks, the following changes occur in the ovaries: Day 1 - about 20 follicles 0.5 mm in size. with an egg in each of them surrounded by granulocytes, begin to grow under the influence of FSH and LH in both ovaries. On the fourth - fifth day-a dominant follicle appears. with a size of 2 mm or slightly more. which is now called a pre-follicular follicle.
Menstruation ends by this time
and the growth of the endometrium in the uterus begins. Seventh day-the dominant follicle grows to a size of 5 mm. and its cavity (Antrum) begins to form, in which follicular fluid accumulates. Connective tissue (theca) grows around the follicle. which leads to the production of the male hormone - androstenedione.
From this day on, the structure of the follicle takes on a unique shape: the follicle consists of two sections. one of which contains LH receptors (up to 1500 in one follicle).synthesis of androgens is controlled by and.
Androgens move to another department, where FSH receptors are located. and here, under the influence of FSH. male sex hormones are converted into female sex hormones through a complex chemical process called romanization.
The level of estradiol in the follicle rises until negative reactions
are triggered, which reduce the level of the hormone FSH in the blood serum, there is a sharp release of luteinizing hormone by the pituitary gland. which leads to the rupture of the follicle and the release of the egg into the abdominal cavity. the method used to choose the dominant follicle. and in which the ovary is still unknown
For the record. However, the dominant follicle can produce the hormone folliculostatin. which forces the pituitary gland to reduce the production of the hormone FSH before ovulation.
Day 13-14 of the cycle - the size of the follicle reaches 15-20 mm. It is on this day that the follicle ruptures and the egg enters the abdominal cavity. Special operative movements of the fallopian tubes - fimbriae - suck the egg into the opening. of the fallopian tube.