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  • Amenorrhea is the medical term for the absence of menstruation1.
  • Catamenia is an alternative word for menstruation. It comes from the Greek ‘katamenia’, where ‘kata’ means ‘by’ and ‘menia’ means ’month’2.
  • Dysmenorrhea is the medical term for the severe cramps that cause period pain. A hormone called prostaglandin causes the uterus to spasm or contract3.
  • Endometrial sparing is the medical term for when the body recycles the uterus lining rather than shedding it. A few percent of women experience it, with very short, light periods4.
  • Endometrium. The endometrium is the lining of the womb. In women of reproductive age, a period comes about when the lining is shed once a month - expelled through the vagina.
  • Enzymes. Enzymes are connected molecules in our bodies that perform certain tasks, like helping us to digest food. They’re like microscopic ‘chemical machines’ - one of nature’s ways of making chemical reactions occur. Enzymes called prostaglandins play a role in periods.
  • Fallopian tubes are passages that transport eggs from the ovaries to the womb. The 16th century scientist Gabriello Fallopio was the first anatomist to describe them5.
  • Hormone. A hormone is a natural chemical in our bodies. Hormones change the way we act, and how our bodies work. Some hormones affect periods - like oestrogen, progesterone, and prostaglandins - hormone-like enzymes.
  • Hymen is the scientific name for a thin fold of skin at the entrance of a girl’s vagina. Almost all girls are born with one, but as they age, the hymen becomes thinner and often develops holes. So the older a girl is, the more likely it is that her hymen will have thinned and shrunk6.
  • Menarche is a medical term for a girl's first menstruation, or period. The name comes from the Greek ‘men’, meaning ‘months’, and ‘arkhe’, meaning ‘beginning’7.
  • Menorrhagia is the medical term for very heavy bleeding. It is often caused by the uterus lining becoming unusually thick. Or, by medical conditions like thyroid problems8.
  • Menstruation is the shedding of the uterine lining, or the endometrium. It is the most visible phase of the menstrual cycle9. Or in everyday words, it’s your period - when your body gets rid of a little blood from your womb.
  • Oligomenorrhea is the medical term for menstruation that suddenly becomes less frequent10.
  • Ovaries produce and store all of our ova, or eggs, before they are released into the womb. The term comes from the Latin, meaning ‘egg keeper’11.
  • Oestrogen is a hormone, a natural chemical that your body makes. (You may see it spelled as ‘Estrogen’ some places, but it’s the same thing.) Oestrogen helps to regulate your menstrual cycle, help you stay healthy, and keep your body in balance. Most contraceptive pills are made with an artificial oestrogen, to stop your ovaries releasing eggs12.
  • Ovulation is when ovaries, the part of the body that store eggs, release them into the womb. It’s part of a fertile woman’s monthly period cycle13.
  • Progesterone is a hormone that regulates the menstrual cycle in our bodies. It is made in the ovaries, and can affect other hormones.
  • Prostaglandins. These are chemicals a woman’s body produces which stimulate the uterine muscles to contract. When we have high levels we can experience strong cramps and period pain.
  • Uterus. The uterus is another name for the womb, the part of our female bodies where an ova - or egg - from an ovary attaches to the endometrium. If a sperm fertilizes the egg, it may go on to develop into an embryo, foetus, and ultimately a baby. If unfertilised, the endometrium is shed - what we know as a period.
  1. 1 Livoti, Dr. Carol, and Elizabeth Topp. 2004. Vaginas: An Owner’s Manual. New York, NY: Thunder’s Mouth Press.
  2. 2 Grahn, Judy. 1993. Blood, Bread, and Roses: How Menstruation Created the World. Boston, MA: Beacon Press.
  3. 3 Livoti, Dr. Carol, and Elizabeth Topp. 2004. Vaginas: An Owner’s Manual. New York, NY: Thunder’s Mouth Press.
  4. 4 Livoti, Dr. Carol, and Elizabeth Topp. 2004. Vaginas: An Owner’s Manual. New York, NY: Thunder’s Mouth Press.
  5. 5 Grahn, Judy. 1993. Blood, Bread, and Roses: How Menstruation Created the World. Boston, MA: Beacon Press.
  6. 6 http://en.wikipedia.org/wiki/Hymen
  7. 7 Delaney, Janice and M.J. The Curse: A Cultural History of Menstruation. Champaign, IL: University of Illinois Press.
  8. 8 Daniels, Patricia, et al. 2007. Body: The Complete Human. Washington, D.C.: National Geographic Society.
  9. 9 Daniels, Patricia, et al. 2007. Body: The Complete Human. Washington, D.C.: National Geographic Society.
  10. 10 Livoti, Dr. Carol, and Elizabeth Topp. 2004. Vaginas: An Owner’s Manual. New York, NY: Thunder’s Mouth Press.
  11. 11 Grahn, Judy. 1993. Blood, Bread, and Roses: How Menstruation Created the World. Boston, MA: Beacon Press.
  12. 12 en.wikipedia.org/wiki/Estrogen
  13. 13 en.wikipedia.org/wiki/Estrogen

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