Menstruation cycle

• Menstruation cycle

  • each month an egg begins to mature in the ovary
  • at the same time, the uterus produces a thickened lining - for pregnancy
  • Every 28 days an egg is released - ovulation
  • if the egg is unfertilised, around 14 days later the uterus lining sheds - period
  • at the same time, the eggs start maturing in the follicle of the ovary
• Hormones and control of the menstrual cycle

  • the pituitary gland secretes FSH which causes an egg to mature
  • FSH causes the ovary to secrete oestrogen
  • Oestrogen causes the pituitary gland to secrete LH which causes the egg to be released from the ovary
• Reproductive system - females

  • uterus - foetus develops here
  • fallopian tubes - where the egg travels to the uterus and may be fertilised
  • ovaries - where the eggs mature, makes oestrogen (controls the build up of the lining of the uterus)
  • Cervix - entrance to the uterus
  • vagina - receives sperm during sexual intercourse
  • vulva - entrance to the vagina
• Reproductive system - males

  • seminal vesicle
  • prostate gland
  • sperm duct - carries the sperm to the urethra
  • scrotum - keeps the testes outside the body for maximum production
  • testes - makes sperm and testosterone
  • Penis - places sperm inside the vagina
  • urethra
• Phases of the menstruation cycle

  1. Menstrual phase : the lining of the uterus starts to shed for around 7-8 days
  2. follicular phase : the uterus begins to regrow to prepare for an egg and the egg starts to mature in the ovary. Days 7-12
  3. Ovulation phase : The ovaries release an egg. Days 13-15
  4. Luteal phase : The egg travels down the fallopian tube, the uterus lining thickens. A fertilised egg will embed itself in the lining and if an egg is not fertilised it is broken down. Days 16-28