Ovulation - a process that is part of the menstrual cycle, during which the follicle ruptures, releasing the egg, which is moving on the fallopian tubes into the uterus, and there awaits fertilization.

In animals ovulation occurs differently. For example, ovulation in female camels induce pheromones Pheromones - the road to the heart of a loved one is through the nose   male camels. In caravans with no males, females there are no heat.

In cats ovulation begins after mating. In chickens, it happens almost every day. But here we are concerned with ovulation in women.

Overview

Ovulation occurs on the fourteenth day of the menstrual cycle The days of the menstrual cycle: Four phases   (the basis of a mean cycle length of 28 days). However, normal ovulation considered starting between the eighth and twentieth day of the menstrual cycle, as some women have a very short cycle, in others - a very long-lasting. Identify the beginning of ovulation by their appearance in most cases impossible.

Before ovulation, the follicle goes through a series of transformations necessary to ensure that the egg was subsequently able to survive. Then, an opening is formed in the follicle, through which the oocyte leaves the follicle. It enters the uterus and, if fertilization occurs, embedded in its wall, and if not, is destroyed within 24 hours.

Background

On protyazhenib process that takes about 375 days, or 13 menstrual cycles, ovarian develops a large group of immature primordial follicles, each of which will gradually become preovulatory follicles. The preovulatory follicle contains not fully mature egg and its surrounding fluid.

Under pozdeystviem luteinizing hormone (LH), the theca cells of preovulatory follicle begin to produce androstenedione, which is converted to estradiol, a type of estrogen Estrogen - the key to bone health . Elevated levels of estrogen stimulates the production of hypothalamic gonadotropin-releasing hormone (GnRH), which signals the hypothalamus to release follicle stimulating hormone (FSH). Increasing concentration in the blood LH and FSH marks the beginning piriovulyatornoy phase, during which the oocyte maturation.

Ovulatory phase

LH commands to the development of proteolytic enzymes that begin to destroy the follicle tissue, forming a hole through which the egg falls into the peritoneal cavity, and further - to the fimbriae (cilia) of the fallopian tubes. These fimbriae help the egg to move through fallopian tubes.

By the time the egg is passed first meiotic phase, during which formed two cells - a large secondary oocyte which comprises the entire cytoplasmic material and a small polar body inactive. Then comes the second phase of meiosis, but it stops at metaphase and so continues until fertilization. If it does not, metaphase does not continue, and the egg is destroyed in a day. Internal uterine mucosa by this time reached their maximum size, as well as cancer of the endometrium.

Postovulatory phase

The life cycle of follicle is completed. Without egg it shrinks, becoming the corpus luteum, the accumulation of cells that produce estrogen and progesterone Progesterone - norm and pathology . These hormones cause endometrial glands begin generating proliferative endometrium place where embryos begin to rise if conception occurs. The corpus luteum continues to hormones before menstruation, after which it is gradually replaced by scar tissue.

Progesterone - a hormone stimulating and regulating essential functions, in particular, menstrual cycles, fertility organism preparation and maintenance of pregnancy. This hormone is produced in the ovaries, the placenta (in pregnant women) and in the pancreas Diabetes and pancreas - the things you need to know . In addition to these features, it has a big impact for the libido.

Pituitary women in the reproductive age, produces follicle-stimulating hormone (FSH) and luteinizing hormone (LH) to ensure the maturation of oocytes and their release from the follicle, which takes place every month. Developing follicles produce hormones - estrogen and progesterone, by which the inner membrane of the uterus (the endometrium) becomes thicker. In the second half of the menstrual cycle, progesterone levels rise, followed by a follicle ruptures and the egg goes down on the fallopian tubes into the uterus - are ovulating. From tissue remains in place ruptured follicle forms a yellow (luteal) body, which continues to produce estrogen and progesterone.

The role of progesterone in the female body

One of the most important functions of progesterone is that in the second half of the menstrual cycle, it stimulates the production of a particular protein endometrium, preparing thus the conditions for the implantation of a fertilized egg and nutrition. If fertilization and implantation does not occur, estrogen and progesterone levels decrease, the endometrium begins to exfoliate and menstruation.

If pregnancy occurs, progesterone begins to produce the placenta; the level of this hormone is high throughout pregnancy. The combination of high levels of progesterone and estrogen inhibits ovulation during pregnancy. Progesterone also stimulates changes in breast feeding woman to her unborn child.

The absence of menstruation is not associated with pregnancy is caused by disturbances in ovulation and the fact that, as a consequence, the progesterone level has not gone down.

Treatment progestogens

The term "progestogen" refers to any hormone products, which have the same influence on the reproductive system, as well as progesterone. Effective substitutes for synthetic progesterone called progestin, was launched in the 1950s. Micronized progesterone capsules became available a few decades later.

The composition of some contraceptives include progestogen-only; they also are useful in treating a variety of disorders, including such as abnormal vaginal bleeding, and amenorrhea The absence of menstruation (amenorrhea) - ambiguous symptom   (absence of menstruation); endometriosis, breast cancer, kidney or uterus, lack of appetite and weight loss associated with AIDS and cancer. Progestogens are also used as an aid in the diagnosis when checking the actions of estrogen Estrogen - the key to bone health .

Birth control pills

Combined oral contraceptives (pills, which include estrogen and progestin) are blocking ovulation and prevent implantation of the embryo if fertilization occurs. These tablets generally need to be taken in a certain order; when the level of the progestin in the tablets is reduced, start menstruating.

The composition of some contraceptive contains only progestin (the funds are sometimes called mini-pills). They can not always suppress ovulation Ovulation - How to determine as accurately as possible? But they make the cervical mucus thicker and unfavorable to sperm, preventing them from entering the uterus. These tablets also attenuate the internal mucosa of the uterine wall, which reduces the likelihood of successful implantation of the embryo. When used properly, the mini-pill only slightly less effective than combined birth control.