The female cycle begins on the first day of menstruation and lasts an average day on 28th The cycle is divided into several phases, in which one fertilization egg matures and after fertilization in the uterine lining can nest. The menstrual cycle by age, the body, the psyche, the metabolism and the production of various hormones in the body affected by.
The cycle is divided into the following phases:
- 1st Half of the cycle: maturation stage of follicles (follicular phase)
- Mid-cycle: ovulation (ovulation)
- 2nd Half of the cycle: luteal phase (luteal phase)
The phases of the menstrual cycle
In each cycle phases of play from different processes within the body.
Maturation stage of follicles (follicular phase)
The first cycle is the first day of menstruation. It starts the ripening of the follicles (follicular phase). The hypothalamus, a part of the midbrain, distributes a hormone GnRH from it, whereupon the formation of follicle stimulating hormone (FSH) in the pituitary gland is stimulated. In ovarian mature now under the influence of FSH about 40 to 100 follicles (follicles up). They produce estrogen – the female sex hormones.
Only one of the follicles developed normally to pounce dominant follicle. If it happens once in a way that several follicles develop further and several be fertilized, resulting multiple births.
Towards the middle of the cycle, estrogen increased the lead to the fact that the cervical canal (endocervical canal) is expanding and the cervical mucus is clear and well spinnable, watery. The mucus can be used together between two fingers in about ten to twelve inches long pull strings. For sperm, he is now particularly well permeable.
The duration of the follicular phase is variable and ends at the time of ovulation. In a cycle of 28 days is about 14 days. In a cycle of 35 days they will take about 21 days.
Just before ovulation, estrogen secretion by a rapid increase in the hormone LH triggered. Together with the already risen progesterone LH triggers the then ten to twelve hours after ovulation from the. This means that a dominant follicle in the ovary mature egg is expelled from the fallopian tube and travels in. Without this LH-peak “of ovulation can not take place.
Ovulation is the prerequisite for a female egg can be fertilized by a male sperm cell. An egg after ovulation is still about 12 to 24 hours fertilized.
Luteal phase (luteal phase)
The second half of the cycle begins with ovulation and always takes 14 days.
From the remains of the follicle that remain in the ovary, become the corpus luteum (corpus luteum). This small gland produces for a short time, the corpus luteum hormone progesterone. It ensures that after ovulation within two days the body temperature increases a woman at least 0.3 degrees Celsius. During the luteal phase, the temperature remains constantly increased.
Progesterone and estrogen in the second half of the cycle ensure that the mucous membrane of the uterus and for receiving a fertilized egg is prepared to set up. The mucosa is then increasingly thicker. Nests are fertilized ovum a one remains in the subsequent menstrual bleeding.
If, however, was not fertilized during the fertile days, the egg is formed the corpus luteum at the end of the cycle back again. The decrease of progesterone triggers the menstrual bleeding, breaks in the lining of the uterus and is expelled.
Bleeding occurred simultaneously with the rise in the blood of women, the values of the hormones estrogen and LH and FSH were connected, and a new cycle begins.