Hormones and Menstrual Cycle

• What happens on Days 1-5 of the Menstrual cycle?


  • Only if there is no FERTILISED EGG the process menstruation occurs
  • Uterus lining and eggs shed and leaves vagina as blood
• What happens on days 5-14 in the menstrual cycle?


  • Oestrogen is released due to FSH
  • When oestrogen levels get too high it inhibits FSH and stimulates the secretion of LH
  • The uterus lining thickens in case of pregnancy (blood vessels dilate)
• What happens on day 14?

  • LH is secreted and Ovulation occurs and a mature egg is released from an ovary
  • After ovulation LH decreases
• What happens on days 15-18 of the menstrual cycle?

  • The uterus lining is maintained again in case there is a fertilised egg
  • FSH, LH and Oestrogen decrease till uterus lining needs to be shed
  • Progesterone is released to help maintain lining
• What does the hormone FSH do?

  • Causes egg to mature
  • Stimulates ovaries to produce oestrogen
  • Stimulates the growth of follicles for eggs
• What does the hormone Oestrogen do?


  • Causes uterus lining to thicken to prepare for pregnancy
  • When there is too much, LH is released to limit amount of FSH secreted
• What does the hormone LH do?


  • Stimulates the release of a mature egg from an ovary
• What does the hormone Progesterone do?


  • Thickens uterus lining again
  • Stops anymore FSH and LH to be secreted
• Order of when hormones secreted:

  1. FSH
  2. Oestrogen
  3. LH
  4. Progesterone
• What secretes FSH and LH?


  Pituitary gland
• What secretes Progesterone?


  Empty egg follicle
• What secretes Oestrogen?


  Ovaries
• What maintains the uterus lining if there is a fertilized egg?

  The Placenta secretes progesterone to maintain uterus lining.