SB7c- The menstrual cycle

• What is menstruation?

  The breakdown of the uterus lining. It begins on day 1 of the cycle and usually lasts around 6 days.
• What is puberty?

  The period in which adolescents start to develop secondary sexual characteristics.
• What happens in week 1 of the menstrual cycle?

  Menstruation which is the breakdown of the uterus lining (bleeding)
• What happens week 2 of the menstrual cycle?

  The uterus lining builds back up to prepare for a fertilised egg
• What happens on day 14 of the menstrual cycle?

  Ovulation which is the release of an egg from the ovaries
• What days are fertilisation most likely to take place?

  Days 14 to 16
• What happens in week 3 of the menstrual cycle?

  The uterus lining continues to build back up
• What happens week 4 of the menstrual cycle?

  If fertilisation occurs, the uterus lining is maintained and menstruation doesn't occur

  • If fertilisation does not occur, on day 28 the uterus lining will start to break down again
• Information about the uterus

  Eggs are kept in the ovaries, and after ovulation travel down the fallopian tubes to go to the uterus

  • If the egg was fertilised, it would implant into the uterus lining. Which remains thick so the embryo can obtain nutrients.
  • Otherwise the egg would break down and pass out
• What is contraception?

  Any method used to prevent pregnancy
• What are the two types of contraception?

  Barrier and hormonal
• Examples of barrier contraception

  1. Condoms
  2. Diaphragm
  3. Caps
  4. Sponges

  These methods work by stopping the sperm from reaching the egg
• What is the permanent version of barrier methods?

  Sterilisation which is done by either cutting the sperm ducts of the fallopian tubes.
• Examples of hormonal contraception

  1. Birth control (a combination of progesterone and oestrogen)
  2. implant underneath the arm (longest lasting, lasts 3 yrs)
  3. Contraceptive patch (releases oestrogen and progesterone and lasts a week)
  4. Contraceptive injection (lasts 2-3 months)
  5. Plastic IUD (releases progesterone, stimulating thick mucus)
• How does hormonal contraception work?

  They release oestrogen and progesterone.

  • If progesterone is released, a thick mucus is stimulated at the cervix, preventing sperm from passing. These contraceptives have less side effects.
  • If oestrogen is released, FSH production is inhibited so no egg will be developed and released.
• Advantages and disadvantages of contraception

  Hormonal- (The pill)

  ✔ More effective at preventing pregnancy

  ❌ Side effects of headaches and nausea

  Barrier-

  ✔ Condoms protect against STDS

  ❌ Diaphragm is unreliable

  ❌ Success rate is lower

  ❌ Condoms can break

  Natural methods are unreliable