Menstrual cycle

• stage 1

  day 1 - 4
• stage 2

  day 4 - 14
• stage 3

  day 14 - 14
• stage 4

  day 14 - 28
• in stage 1

  • uterus lining breaks down
• in stage 2

  • uterus lining builds up again
  • creating a thick spongy layer filled with blood vessels
• stage 3

  • egg develops and is released from ovary
  • called ovulation
• Stage 4

  • wall is maintained
  • if no egg has fertilised, cycle repeats
• FSH

  produced in pituitary
• oestrogen

  produced in ovaries
• LH

  produced in pituitary
• Progesteron

  Produced in ovaries - remains of follicle after ovulation
• FSH causes

  egg to mature in follicle ( ovary )
• Oestrogen causes

  lining of uterus to grow
• LH causes

  release of egg ( ovulation )
• Progesterone

  maintains lining of uterus during 2nd half of cycle

  when it falls the lining breaks down
• FSH

  stimulates ovaries to produce oestrogen
• Oestrogen

  Stimulates release of LH ( causing the release of the egg )
• oestrogen

  inhibits release of FSH
• LH

  stimulates release of none
• Progesteron

  inhibits release of LH and FSH