Before talking about the phases of the menstrual cycle, it must be said what it is. The menstrual cycle is the monthly physiological changes in a woman’s ovaries and genitals that occur in order to prepare the body for a possible pregnancy. Not only reproductive organs take part in this process, an important role is given to the brain and the hormonal system.
The entire cycle can be conditionally divided into four segments. Some scientists talk about the incorrectness of this division and distinguish only two phases of the menstrual cycle: follicular and luteal. In fact, both classifications are almost identical. The first classification, which distinguishes four phases of the menstrual cycle, most accurately reflects the processes of preparation for a probable pregnancy. About them and will be discussed below.
The first two phases reflect the preparation for egg production, the last two - the formation of the egg, preparation for conception and conception / death of the egg. Let's consider each of them separately.
The first phase of the cycle begins on the very first day of menstruation. At this time, the endometrium is rejected, and the body directs its attention to the formation of a new egg. In time, this process takes from three to six days, but even before the end of menstruation, the next phase, follicular, begins .
The second period of the cycle lasts approximately two weeks after the period ends. The cycle in this segment is focused on the development of the follicle under the influence of the hormone, in one of which (dominant) the egg will mature later. At the same time, estrogen renews the lining of the uterus and makes the cervical mucus immune to sperm.
The duration of the next period, the phase of ovulation, is approximately three days. At this time, the level of follicle-stimulating hormones decreases, which give way to luteinizing, which makes cervical mucus susceptible to sperm. In addition, this hormone affects the completion of egg maturation, after which it is released from the follicle (ovulation occurs). A mature egg moves into the fallopian tubes, where it awaits fertilization for about two days.
It is replaced by the fourth phase of the menstrual cycle - luteal. After the egg is released from the follicle, it goes to fertilization, and the follicle itself begins to produce progesterone. The role of progesterone is to prepare the uterine endometrium for the absorption of a fertilized egg. At the same time, the production of luteinizing hormone stops , which again makes the neck connection immune to sperm. The duration of the fourth phase of the cycle can last up to 16 days. The body is in the stage of waiting for the uterus to absorb a fertilized egg, which occurs 6-12 days after fertilization.
If the uterus takes an egg, a special hormone immediately begins to be produced, under the influence of which the corpus luteum will function throughout pregnancy. It is to this hormone that pregnancy tests are sensitive.
If fertilization has not occurred, the egg, along with the corpus luteum, dies, progesterone ceases to be produced, this inevitably follows destruction and rejection of the endometrium. In other words, menstruation begins, and all phases of the menstrual cycle again replace one another.
The following fact is noteworthy. All four phases of the menstrual cycle develop under the influence of hormones that affect not only the physiology, but also the emotional state of the woman. The ancient Chinese believed that knowledge of the characteristics of each stage of the cycle is directly related to the well-being of women. So, the accumulation of energy occurs before ovulation, therefore, if a woman retained energy in the first half of the cycle, this allowed her to live in harmony with herself and the world.