Puberty and the Menstrual Cycle

• Release of an egg from a woman's ovaries

  Part of the menstrual cycle
• Puberty


  • Hormones promote sexual characteristics
  • Body starts releasing sex hormones that trigger secondary sexual characteristics such as the development of facial hair in men and breasts in women
• Testosterone


  Main reproductive hormone in men, produced by the testes and stimulates sperm production
• Oestrogen


  Main reproductive hormone in women, produced by the ovaries and involved in the menstrual cycle
• The Menstrual Cycle

  1. Stage 1: Lining of the uterus breaks down

  2. Stage 2: Lining of the uterus builds up

  3. Stage 3: Egg is released

  4. Stage 4: Lining of the uterus is maintained
• Hormones involved in the menstrual cycle

  • FSH (Follicle-Stimulating Hormone)
  • Oestrogen
  • LH (Luteinising Hormone)
  • Progesterone
• FSH


  Produced in the pituitary gland, causes an egg to mature in the ovaries, stimulates the ovaries to produce oestrogen
• Oestrogen


  Produced in the ovaries, causes the lining of the uterus to grow, stimulates the release of LH and inhibits the release of FSH
• LH


  Produced by the pituitary gland, stimulates the release of an egg at day 14 (ovulation)
• Progesterone


  Produced in the ovaries by the remains of the follicle after ovulation, maintains the lining of the uterus during the second half of the cycle, inhibits the release of LH and FSH
• When the level of progesterone falls, the lining of the uterus breaks down