The follicular phase is an element of the normal menstrual cycle and falls in its first half. In regularly menstruating 28-day cycles, the length of the follicular phase is approximately 14 days. The beginning of the phase marks the appearance of menstrual bleeding and is associated with a significant decrease in the concentration of progesterone with a simultaneous increase in the concentration of estrogens.

The follicular phasenext to the luteal phase and ovulation is part of the menstrual cycle in a regularly menstruating woman lasting about 28 days. Of course, the length of the cycle is an individual matter, depending on many factors, including environmental ones. Therefore, the length of the first phase of the cycle also varies in women, but it was assumed that it should normally last 14 days. The beginning of the follicular phase is the period of menstrual bleeding, and the end is the day of ovulation, which can be determined with high probability based on reliable observations.

Follicle-stimulating hormone: regulator of the first phase of the cycle

Follicle stimulating hormone is an example of a protein found in the human body with no gender relationship. The secretion mechanism of this substance is regulated by feedback with the stimulating factor folliculiberin produced by the hypothalamus. The entire pathway is correlated with the amount of estradiol in the body. The role of the FSH hormone is to stimulate the ovarian follicles to the production of the female sex hormone - estrogen, adequate to the needs.

Physiology - the maturation process of ovarian follicles

The process of ovarian follicle maturation continues in the fetal period, around 16-20 weeks of a properly developing pregnancy. During this time, the largest increase in the number of bubbles is observed, reaching the size of 6-7 million. They are called primary follicles, within which the primary egg cell - the oocyte, matures. In the second half of pregnancy, the number of primary ovarian follicles drops sharply.

During the follicular phase, further transformation of primary follicles takes place under the influence of FSH. In the histological structure of the ovum, a transparent shell begins to form, while the existing granular layer undergoes a proliferation process, which translates into an increase in the concentration of estrogens. At this stage, the interior of the ovarian follicles is filled with abundant follicular fluidjust in the above-mentioned estrogens. About the 6th day of the menstrual cycle, the dominant follicle is recruited. The increase in the concentration of estradiol is of great importance in this process - the increased concentration causes a relative decrease of the FSH hormone, which causes the development of only one dominant follicle. At the turn of the follicular and ovulatory phase, the peak of estrogen secretion takes place, and more precisely, it falls 24-36 hours before the scheduled time of ovulation.

Hormone management during the follicular phase

The beginning of the follicular phase is simultaneously a decrease in progesterone concentration and an inversely proportional increase in the level of estrogens. As a result, the reconstruction of the lining of the uterine cavity takes place in the form of its thickening. It is one of the elements of preparation for a possible pregnancy. The estrogens produced in this phase also affect the image of the cervical mucus. It acquires features that facilitate fertilization. I become definitely more stretchy, less sticky, and more, which gives a feeling of moisture.

Standards for follicle-tropic hormone

It has been established that the normal concentration of follicle-phosphorus hormone in women in the reproductive period ranges from 1.4-9.6 IU / l .

Both lower and higher values ​​are deviations from the accepted norm and should be a cause for concern and should be the basis for starting the diagnosis. It has been established that low levels may be associated with pituitary or hypothalamic insufficiency, while excess hormone may suggest ovarian failure.

The endometrium in the first phase of the cycle

The follicular phase is reflected in the changing structure of the uterine mucosa. The period of menstruation is associated with the process of exfoliation of epithelial forms, which in turn leads to thinning of the uterine mucosa. In the following days, endometrial proliferation begins. Initially, only the glandular epithelium, fulfilling the secretory function, and on the remaining days also the deeper layers.

Category:

Female diseases