1. 4 stages
   1. stage 1
      1. day 1 - 4
      2. bleeding starts
         1. uterus lining breaks down
   2. stage 2
      1. day 4 -14
      2. uterus lining builds up
         1. spongy layer
         2. full blood vessels
         3. ready for fertilised egg
   3. stage 3
      1. day 14
      2. egg developed and released
   4. stage 4
      1. day 14 - 28
      2. uterus wall maintained
      3. day 28 : no egg then uterus lining breaks down
2. Hormone Control
   1. Follicle Stimulating Hormone (FSH)
      1. produced: pituitary gland
      2. causes
         1. egg matures in one of the ovaries
         2. ovaries produce oestrogen
   2. Oestrogen
      1. produced: ovaries
      2. causes
         1. inhibits release of FSH
         2. pituitary to produce LH
   3. Luteinsing Hormone
      1. produced: pituitary gland
      2. causes
         1. release of an egg (mid-menstrual cycle)
3. Hormones in menstrual cycle
4. Oestrogen & Progesterone in Menstrual Cycle
5. FSM and LH in Menstrual Cycle
6. Fertility
   1. Reduce fertility
      1. oestrgen
         1. prevent release of egg
            1. should release egg?
            2. take every day
            3. keeps level high
            4. inhibits FSH production
            5. egg development & production stops
         2. contraception
            1. the pill
            2. oral
         3. Advantages
            1. 99% effective
            2. reduces risk of some cancers
         4. disadvantages
            1. not 100% effective
            2. side effects
            3. headache, nausea
            4. not protection against STD
   2. Increase Fertililty
      1. FSH too low
         1. eggs not mature
            1. no egg released
         2. take FSH
            1. stimulate egg production (ovaries)
            2. stimulates oestrogen production (ovaries)
            3. Pituitary gland releases LH
            4. egg released
            5. Advantage
            6. helps increase chance of pregnancy
            7. disadvantage
            8. not always work
            9. expensive
            10. too many eggs
            11. multiple pregnancies
   3. IVF
      1. in vitro fertilisation
         1. womans egg
            1. fertilise by mans sperm
            2. grow into embryo
            3. transfer into uterus
      2. hormones
         1. before egg collection
            1. stimulates egg production
         2. oestrogen / progesterone
            1. implantation into uterus greater success
      3. problems
         1. reaction to hormones
            1. abdominal pain
            2. vomiting
            3. dehydration
         2. increased risk cancer
            1. position unclear