During puberty, special hormones from the brain cause the ovaries to release an egg, which is called an ovum. The ovaries then produce other special hormones called oestrogen and progesterone that cause the eggs in the ovaries to develop so that they are ready to be released.
Each month, one egg leaves one of the ovaries travelling down one of the fallopian tubes on its way to the uterus. Meanwhile, the uterus, also called the womb, starts to get prepared for the egg by building up a thicker lining of special tissue that is called the endometrium. If the egg arrives at the uterus as a fertilised egg, one that has been met by sperm from the male, it attaches itself to this cushion-like wall, and goes on to use the extra blood and tissue to nourish itself as it slowly develops over 9 months into a baby. Usually, the egg just passes right through without being fertilised and just dissolves. Since the uterus no longer needs the thicker lining, it sheds this extra blood and tissue through the vagina. This loss of tissue is called menstruation or the period. This cycle will happen nearly every month until the ovaries stop releasing eggs, usually between the ages of 45 and 55.
The menstrual cycle is actually a very special and very complicated process that happens because many parts of the body are working together. The brain, ovaries and other hormone producing glands in the body, all have to work together properly to make this cycle of producing an egg, making the uterus ready for it, and then shedding the special lining work. Not to mention the extra-complicated work that happens if the egg does get fertilised and develops into a baby. Females are truly amazing!
(published with permission in writing from:http://www.natracare.com)
