Ever hear an older girl or lady talking about her monthly period? Or maybe you’ve heard the word in a television ad?
Chances are, she’s not talking about the kind of period that goes at the end of a sentence.
That’s because women experience something called “menstruation,” the official word for a “period.” It is also referred to as “bleeding,” but bleeding during a period isn’t like bleeding from a cut. A period happens when a woman’s body sheds the inside lining of her uterus (the place where a baby would grow if she was pregnant). The lining of the uterus is made of tissue and blood. When it falls away from the uterus, it flows through the cervix and out the vagina.
Most grown-up women get their periods about once a month. Men don’t have a uterus, so men don’t ever get periods.
Girls start to get periods during puberty. It is one of the processes regulated by hormones. The average age for the first period is 12, but it can be anywhere from 10 to 15.
As the reproductive system matures, girls begin their menstrual cycles. This is the cycle when the woman’s body releases an egg from the ovaries and builds up the lining of the uterus. If the egg doesn’t get fertilized with sperm as it moves down the fallopian tubes, the body sheds the uterus lining and the egg. Then the body starts all over again. The whole process is a repeating cycle that takes about a month, although it can be very irregular in the beginning.
If a woman’s egg is fertilized at some point during the cycle, it can implant in the uterus wall. There, it will grow into a baby. If this happens, the lining of the uterus does not shed and there is no period.
Periods are part of a repeating cycle. There are lots of other cycles in nature, too. Every year, we cycle through the four seasons. The moon goes through cycles. Tides in the ocean are cycles. What are some other cycles you can think of? What other patterns do you see in nature? Can you draw them?