The menstrual cycle is the process that prepares women's uterus for pregnancy every month. It is a cycle through which the female ovules are developed, and different physical and psychological changes occur. The result of the cycle can be pregnancy or menstruation. If the ovum is fertilized, pregnancy happens; if not, menstruation occurs. The cycle begins with the first day of menstruation and ends one day before the next menstruation. It consists of four phases: menstruation, follicular phase, ovulation, and luteal phase.
Menstruation begins with the first day of bleeding. It usually lasts between 3 and 5 days, depending on each body. It is the phase in which the body expels the endometrium because there was no fertilization of the ovule.
In this phase the body begins to prepare for a pregnancy. For this, estrogen (a type of hormone) is responsible for thickening the endometrium, the inner layer of the uterus, for possible fertilization. At the same time, a hormone called folicestimulante (HEF) increases, which produces the growth of the ovarian follicles. Each follicle contains an ovule.
At this moment, an ovarian follicle is broken and an oocyte is released. This oocyte travels to the fallopian tube, where it will wait between 12 and 48 hours to be fertilized, otherwise it will begin to disintegrate.
After the oocyte is released, the follicles are transformed into the corpus luteum, a gland responsible for generating progesterone. When fertilization does not occur, the preparation process is interrupted with the detachment of the endometrium, and then menstruation takes place restarting the cycle.
Hormones are molecules produced in the endocrine glands, which are transported through the bloodstream and have the function of sending chemical messages that regulate the behavior and physiology of tissues and organs. Their effects are strong and therefore only a tiny amount are needed to generate large changes. Among the most common processes where hormones play a fundamental role are: growth and development, metabolism, reproduction, and moods.
Estrogen is a sexual hormone produced in the ovaries. Its function is the development and regulation of the female reproductive system and secondary sex characteristics.
Estrogens are responsible for:
This hormone is also known to initiate activation processes of the nervous system. In this way they bring physical, psychological, and sexual vitality to women, as well as dynamism and optimism.
Progesterone is a sexual hormone produced in the ovaries, mainly by the corpus luteum. It acts mainly during the second part of the menstrual cycle, the luteal phase. If the embryo is conceived, the uterus and the breasts must be conditioned so that the implantation and development of the embryo occurs in a safe way. Some functions of the progesterone is to keep the endometrium in place, establish the placenta, stimulate the growth of maternal breast tissue, prevent lactation, and strengthen the pelvic wall muscles in preparation for labor. But, if the egg is not fertilized, the corpus luteum breaks down, and the production of progesterone decreases. Therefore the endometrium is no longer maintained by progesterone, causing itto break down, and menstrual bleeding occurs.
Progesterone in other scenarios
When progesterone levels are too low