Girls get periods because they have a uterus and ovaries, which are essential for the menstrual cycle, a process boys generally lack.
Here's a breakdown:
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The Biological Difference: The primary reason girls (assigned female at birth) experience menstruation and boys (assigned male at birth) do not stems from fundamental differences in their reproductive systems.
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The Uterus: The uterus is a muscular organ in the female reproductive system where a fertilized egg implants and develops into a fetus. During a menstrual cycle, the lining of the uterus (the endometrium) thickens to prepare for a potential pregnancy. If pregnancy doesn't occur, this lining sheds, resulting in menstrual bleeding. Boys do not have a uterus.
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The Ovaries: The ovaries produce eggs and hormones (estrogen and progesterone) that regulate the menstrual cycle. These hormones stimulate the thickening of the uterine lining. Boys have testes that produce sperm and testosterone.
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The Menstrual Cycle Explained: The menstrual cycle is a recurring process involving hormonal fluctuations that prepare the female body for pregnancy. It includes ovulation (the release of an egg from the ovary) and the preparation of the uterine lining. When fertilization doesn't happen, the uterine lining sheds, leading to menstruation, also known as a period.
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Puberty Onset: Generally, girls begin puberty between ages 8 and 13, initiating menstruation. Boys typically start puberty a little later.
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Exceptions (Rare): While extremely rare, there are very exceptional medical conditions where individuals assigned male at birth might experience something resembling menstruation due to complex hormonal imbalances or other unusual circumstances. Conversely, some individuals assigned female at birth may not experience menstruation due to a variety of medical reasons. These situations are very uncommon. The 2011 date on the reference refers to the date of an online post and is not relevant in this explanation.
In summary, menstruation is a natural process for females with a uterus and ovaries related to their reproductive cycle, which is not present in males.
