Menstrual cycle

Menstrual cycle - changes in a woman's body, repeated at a proper time manifested outwardly in the form of bleeding from the genital tract. The menstrual cycle is calculated from the first day of the onset of menstruation before the first day of the next menstruation. Menstrual cycle runs in the background of cyclic changes of the functional state of many systems of the female body and is closely related to the reproductive function of women.
Menstruation begins with a 13 - 14 years and continue to 45-50 years. The time of the first menstruation depends on a number of factors: physical development, nutrition, social conditions, climate, diseases, etc. for women living In an average strip of the European part of Russia first menstruation appears aged 13 to 14 years. The emergence of first menstruation before 11 and 17 years later reveal a violation of ovarian function, the pituitary gland and other endocrine glands. In addition, the onset of first menstruation after 18-20 years testifies to the underdevelopment of the reproductive system of the girl.
Regular M. C. is set immediately after the first menstrual period or over the next two years. The duration of the menstrual cycle characterized by a fairly wide range of individual physiological oscillations in the range from 21 to 35 days.
The normal duration of menstrual bleeding average of 3-7 days. The average blood loss during menstruation is 50-70 ml
Menstruation - recurring at the end of the menstrual cycle the shedding of the endometrium, accompanied by physiological bleeding. Menstruation how would completes the cycle of changes in the reproductive system, if fertilization ripened egg did not happen.
Cyclic changes are most pronounced in sexual apparatus women, namely in the ovaries and the mucosa of the uterine cavity. However, changes in the sex organs are private demonstration General, waves flowing changes in a woman's body. Thus, rhythmically repeated changes in menstrual cycle occur throughout the body (the cycle of the whole body), in the ovaries (ovarian cycle), in the uterus (the uterine cycle).
Cyclic changes in a woman's body is clear from the nervous and vascular systems. Many women before menstruation occurs irritability, drowsiness, fatigue, slight increased heart rate, increased blood pressure. During menstruation the pulse is slower blood pressure decreases. All these phenomena disappear after menstruation.
Under the influence of the physiological rhythm of the changes in the hypothalamus and the pituitary gland, which is expressed in changes in the secretion of gonadotropin-releasing hormone (see), in the ovary occurs cyclical changes, which can be divided into three phases: a phase of growth and maturation of ovarian follicle, phase ovulation and phase yellow body. Under the influence of follicle-stimulating hormone in the pituitary gland is a process of maturation of the follicle, which takes the first half M. C. In the process of development of the follicle significant changes occur in all parts of the follicle: the egg, the epithelium of the follicle, connective tissue sheath. Mature follicle increases in size, its pole begins to stuff Hisself out above the surface of the ovary, ovarian tissue in this place becomes thinner. On 14-15 th day of the menstrual cycle is the gap Mature follicle and output Mature, ready-to-fertilization - ovulation. Ovulation occurs under the influence of follicle-stimulating and luteinizing hormones of the pituitary gland (see Gonadotropic hormones). A certain role in the rupture of the follicle plays and oxytocin. The time of ovulation is the most favorable for fertilization.
On the site of rupture of the follicle produces a yellow body. With the formation of yellow body begins luteal phase of the menstrual cycle. The development of the yellow body comes under the influence of two gonadotropic hormones of the pituitary luteinizing and luteotrophic. Yellow body produces a hormone - progesterone. If not happened the ovum is fertilized, a yellow body reverses its development at the end of the menstrual cycle.
Under the influence of hormones produced by the ovaries (see Sex hormones), changed the toneand excitability and perfusion of the uterus. Clear changes occur in the endometrium. Uterine cycle as ovarian, usually 28 days; it distinguishes the following phases: desquamation, regeneration, proliferation and secretion. Phase desquamation manifests itself menstrual bleeding. This functional layer of the endometrium breaks down, rejected, and stands out together with the contents of uterine glands and blood. Phase desquamation coincides with the beginning of reverse development luteum in the ovary. Regeneration phase - recovery mucous membrane begins during the period of menstruation and ends at 5-6-th day of the cycle. The restoration of the functional layer is due to the epithelium residues glands, which are located in the basal layer of the endometrium. Phase proliferation of epithelial coincides with the process of follicle maturation and continues until the 14th day of the cycle (in a 28-day cycle). Under the influence of estrogen hormone is the proliferation of the stroma and the growth glands mucous membrane. The mucous membrane of the uterus thickens in 4-5 times. Phase secretion coincides with the phase of development of the yellow body. Under the influence of hormone yellow body cancer of mucous membrane of the uterus begins to develop the secret cavity their expanding. Stroma cells are rounded starting to remind decidual cells during pregnancy. In the mucosa is glycogen, phosphorus, calcium , and other substances. As a result of these changes in the mucous membrane of the uterus are created conditions for the implantation of the ovum and development of the embryo.
These cyclical changes are repeated through the correct intervals throughout the childbearing period of a woman's life. Termination of cyclic processes occur only in connection with such physiological conditions like pregnancy and breast-feeding. Menstrual cycle disorder can occur in a number of pathological conditions and wear cyclical: 1) violation of the length of the menstrual cycle - frequent menstruation (protomedeia), infrequent menstruation (optimizarea); 2) violation of the duration of menstruation is a long menstruation (polimenoreya), short menses (oligomenorea); 3) changing the number of loose blood - heavy menstruation (hypermenorrhea), menstruations (hypomania).
These violations menstrual cycle is usually accompanied with each other. So, polimenoreya often combined with gipermenorea, the violation referred to as menorragia. Hypomenorrhea often combined with oligo-and optimizarea, constituting the so-called gipomenstrualny syndrome. Acyclic uterine bleeding not associated with the menstrual cycle, known as metrorragia (see Uterine bleeding). Menstrual disorders can wear and acyclic character - the so-called anovulatory bleeding (see Metropolia). The absence of menstruation is called amenorrhea (see). Painful menstruation called algomenorea (see Dysmenorrhea).
The most characteristic of the normal menstrual cycle is its dvukhfaznoi: availability of follicular phase and luteum in the ovary and accordingly phase proliferation and secretion in the endometrium. To judge the usefulness of the menstrual cycle only on the basis of the regularity of menstrual discharge because rhythmic menstrualnopodobne bleeding may occur in single-phase anovulatory cycle (see).
For detection of two-phase nature of the menstrual cycle, there are a number of tests of functional diagnostics. Regular measurement of the morning temperature in the rectum (rectal temperature) gives the opportunity to get a typical two-phase cycle of a temperature curve - the day before or the day of ovulation the temperature rises by 0.2 to 0.6 degrees and holds on these figures the entire second half of the menstrual cycle, falling for 1-2 days before menstruation. Cytological examination of vaginal smears of different periods of the menstrual cycle you can mark certain dynamic changes. As we approach the day of ovulation in smears begin to prevail in large cells with point pinnatisected kernel (surface, orogovevshie cells). In phase yellow body dominated by intermediate cells smaller, with darker protoplasm and well-defined nucleus. In the follicular phase of the cycle in the cervical canal begins to accumulate transparent vitreous mucus outer jaws cervical several expands, so when inspecting the neck in mirrors outer jaws has the form pupil (symptom of "maybe"). Placed on a glass slide and dried mucus from the cervical canal forms specific crystals resembling the picture of a fern. In the luteal phase of mucus in the cervical canal disappears and this symptom is missing. Methods of functional diagnostics provide a clear understanding of the nature of the menstrual cycle and are widely used in clinical practice.
Women with menstrual disorders should be directed to the examination and treatment to the doctor-gynecologist.

Menstrual cycle - rhythmic changes in a woman's body, repeating with the correct intervals. M. C. - complex Fiziol. the process involving the Central and peripheral nervous and endocrine systems. Externally, M. C. appears periodically coming (every 21 - 30 days) bleeding from the genital organs - menstruation (lat. menstruatio, raenstrus, menses, purgatio menstrua periods of "purification").