menstrual period, otherwise known as menstruation or menses, is
just one part of the menstrual cycle, a 28-day long process continually
performed by your body. The menstrual cycle involves the uterus,
cervix, ovaries, fallopian tubes and vagina. These are all aspects
of your reproductive system because the menstrual cycle is your
body’s way of preparing you for pregnancy. Every month, the
reproductive system practices for fertilization of your eggs and
the development of a fetus. The process is guided by hormones,
particularly estrogen, progesterone, follicle-stimulating hormone
(FSH) and luteinizing hormone (LH).
Every month, your uterus prepares for an embryo by thickening
its lining with tissue and blood. When an egg is released (ovulation)
and if it isn’t fertilized, then the uterus will shed this
lining. And that is what your period is—simply the shedding
of the uterine lining.