menstruationscykelfas

Menstruation is a natural process that occurs in the female reproductive system, typically beginning around the onset of puberty and continuing until menopause. The menstrual cycle is the series of changes that occur in the female reproductive system each month, preparing the body for a potential pregnancy. It is regulated by hormones, primarily estrogen and progesterone, which are produced by the ovaries.

The menstrual cycle is divided into four main phases: menstruation, the follicular phase, ovulation, and the luteal phase. Menstruation, also known as the menstrual phase, is the shedding of the uterine lining (endometrium) that occurs if pregnancy does not occur. This phase typically lasts 3 to 7 days and is characterized by vaginal bleeding.

The follicular phase begins after menstruation and lasts until ovulation. During this phase, the follicle-stimulating hormone (FSH) stimulates the growth of follicles in the ovaries, and one dominant follicle begins to produce estrogen. The rise in estrogen levels triggers a surge in luteinizing hormone (LH), which leads to ovulation.

Ovulation is the release of a mature egg from the dominant follicle. It usually occurs around the middle of the menstrual cycle, approximately 14 days after the start of menstruation. The egg travels down the fallopian tube, where it can be fertilized by sperm.

The luteal phase begins after ovulation and lasts until the next menstrual period. During this phase, the corpus luteum, a temporary endocrine structure formed from the remains of the follicle, produces progesterone. Progesterone prepares the uterine lining for potential implantation of a fertilized egg. If fertilization does not occur, the corpus luteum degenerates, leading to a decrease in progesterone levels and the shedding of the uterine lining, initiating the next menstrual cycle.

The length of the menstrual cycle can vary from person to person and can be influenced by factors such as age, overall health, and hormonal fluctuations. Regular menstrual cycles typically range from 21 to 35 days, with an average length of about 28 days.