SEXUAL CYCLE IN FEMALES
As we have already discussed that the main function of ovary in females is to produce ova or eggs. From the birth of a girl child to the age of puberty her ovary contains thousands of immature eggs in immature follicles. On attaining puberty, one follicle develops at a time to form a mature ovum or egg. On maturing, the follicle bursts and the ovum is released from the process. The process of releasing of an ovum or egg from an ovary is called ovulation.
Ovulation takes place on the 14th day after the completion of menstrual cycle of 28 days in a normal female. After ovulation the released ovum reaches the uterus, where it waits to get fertilized by the sperm of male. Before every ovulation, the inner wall of the uterus becomes thick and soft with lots of blood vessels in it. the reason for these changes in uterus is that in case the ovum or egg released by the ovary get fertilized by the sperm, then the uterus has to keep this fertilized ovum for further development. But, if the fertilization of the ovum does not take place, then the ovum dies and the inner wall of the uterus breaks down along with its blood vessels. This produce blood and other tissues which move out of the vagina in the form of bleeding called menstrual flow or menstruation. It lasts for 3-5 days.
This cycle of events of menstruation takes place again and again in ovaries and uterus after every 28 days to 30 days in a normal female and is called menstrual cycle. So the process of menstruation takes place in a normal woman after every 28 to 30 days.
In female the commencement of menstruation takes place at puberty and is called menarche, while it stops at the age of about 50 years. After this age the flow of menstrual fluid stops and the ability of a female to reproduce is lost. This stage is called menopause. Thus, menopause may be defined as that age at which the menstruation stops and a woman loses her ability to reproduce.