Menstruation is the shedding of the uterine lining (endometrium) that occurs in females of reproductive age as a part of the menstrual cycle. It occurs for the following reasons:
Ovulation: The menstrual cycle is controlled by the release of hormones from the hypothalamus, pituitary gland, and ovaries. The release of these hormones triggers ovulation, the process by which an egg is released from the ovary.
Hormonal changes: The hormonal changes that occur during the menstrual cycle also cause changes in the endometrium. The endometrium thickens in preparation for a possible pregnancy. If pregnancy does not occur, the thickened endometrium is shed, resulting in menstruation.
Menstrual bleeding: When the egg is not fertilized, the levels of estrogen and progesterone decrease, causing the blood vessels in the endometrium to constrict and the endometrium to shed, resulting in menstrual bleeding.
Menstrual cramps: Menstrual cramps are caused by the contraction of the uterus as it sheds its lining. The cramps are caused by the release of prostaglandins, chemical messenger that cause the uterus to contract.
Reproductive system maintenance: Menstruation is also an important mechanism for the maintenance of the reproductive system as it helps to clear out old tissue and prepare the uterus for a potential pregnancy.
In summary, Menstruation is a natural physiological process that occurs in females of reproductive age as a result of hormonal changes, ovulation and shedding of the uterine lining. It’s essential for the maintenance of the reproductive system and the possibility of pregnancy.