Why do girls have menstrual periods?

Answer 1

The reason why women menstruate is linked to reproduction and the rather short lifetime of an unfertilised egg once it has been released from the ovary at ovulation. First and foremost, hormones influence menstruation. Weight also influences hormonal balance and menstruation.

Answer 2

The body's maintenance of the uterus in human females has developed into a process to provide entirely new uterine tissues for each regular ovulation. The discharge during menstruation (a period) consists of unfertilized eggs and the lining of the uterus.

Since another ovulation follows menstruation, it is still possible for a woman to become pregnant through sexual intercourse during her period. However, this is much less likely than at another time.

Answer 3

A female's body prepares for pregnancy in specifc stages. What happens to the womb (the uterus) at the beginning of a monthly cycle (not meaning period here, just the cycle every month), the hormones increase. The increased hormones triggers the uterus to prepare for the possibility of a fertilized egg. The preparation consists of the uterine walls becoming thicker and more infused with blood. The blood vessels are always there, but more blood comes into the tissues (into the walls of the uterus).

About mid-month, ovulation occurs (mid-cycle - which depends on the date of the last menstrual period and the date it ends). The egg has been released from the ovary and enters the fallopian tube (one ovary with one tube is on each side of the uterus). If a sperm meets an egg and fertilizes it, it will implant in the blood-rich wall of the uterus.

If the egg is never fertilized, the body must expel the egg, the sperm, and the lining that built up in the uterine wall. As the hormone levels drop, the tissue "sloughs off" which means it kind of slides off, rather like topsoil makes mud in the rain and runs off a hill. As that blood-rich tissue sloughs off, it moves downward with gravity, movement/activity, and some muscle involvement. It moves from the uterus, out a small (normal) opening in the cervix, and continues out the vagina as "a flow" of blood, or what most people call a "period". The blood flow can start slow or fast, light or heavy, light reddish to darker reddish--everyone's period is different. Often, it begins with a mildly heavy discharge of blood, and by the end, it can be light spotting. Some people have light spotting at first, then a mildly heavy flow.

The period lasts anywhere from 2 to 7 days, with an average of 4 to 5 days, during which the hormones remain low. The uterus empties, and by the end of the period the cycle I've described begins again.

As an historical side-note, no one knows for certain how women and men centuries ago reacted to the menstrual flow of monthly bleeding. Biblically, it was considered a time of "uncleanliness" and many medical historians believe women were separated from men even in the "cave man days". Some religions still teach that monthly bleeding is an unclean time. However, in some ancient cultures, it was celebrated as female fertility.

But, even as late as the 1950s-1960s, physicians taught that sex should be avoided during the menses. Now, though, more couples decide whether to have sex despite the menstrual blood. There is no medical reason to not have sex when bleeding, unless the female has a lot of negative symptoms and prefers not to have sex. Many men still find the bleeding a turn-off.

Answer 4

Every month the body gets itself ready to accept sperm and get pregnant by making the wall of the uterus thick with blood and nutrients for the baby. When the sperm doesnt come it gets rid of it shedding the layer of blood

Answer 5

Because their eggs get attached to the vaginal wall and when there isn't sperm to support the egg, the vagina becomes over fertle and the vaginal wall bleeds away.