the menstrual cycle

• What is the endocrine system?

  It is a system where hormones are released by glands into the bloodstream to trigger effects in target organs
• What role do reproductive hormones play during puberty?

  They cause secondary sexual characteristics to develop
• What hormone do the testes produce in men?

  Testosterone
• What does testosterone stimulate in men?

  It stimulates the testes to produce sperm
• What hormone do the ovaries produce in women?

  Estrogen
• What is ovulation?

  It is the release of an egg from the ovary
• What happens to the uterus lining in preparation for ovulation?

  It becomes thick and spongy
• What happens to eggs in the ovaries once puberty begins?

  They start to mature and an egg is released every 28 days
• What occurs if the egg is fertilized?

  It can implant into the uterus wall and develop into a baby
• What happens if the egg does not get fertilized?

  Both the egg and the uterus lining are released as a period
• What are the four key hormones involved in the menstrual cycle?

  • FSH
  • LH
  • Oestrogen
  • Progesterone
• What does FSH do?

  It causes an egg to mature in the ovary
• What is the role of LH?

  It causes the egg to be released during ovulation
• What are the functions of oestrogen and progesterone in the menstrual cycle?

  They maintain the uterus lining in case the egg is fertilized
• What happens to FSH and LH levels when progesterone is present?

  Progesterone stops the pituitary gland from releasing FSH and LH
• What happens to progesterone levels if fertilization does not take place?

  The level of progesterone falls
• What is the significance of the menstrual cycle graph?

  It shows the levels of FSH, estrogen, LH, and progesterone during the menstrual cycle
• What triggers the release of LH?

  The increase in oestrogen levels
• What happens to the levels of FSH and estrogen during the menstrual cycle?

  As oestrogen increases, it inhibits the production of FSH
• What is the outcome of the menstrual cycle if fertilization occurs?

  The uterus lining remains thick to support the developing embryo
• What is the outcome of the menstrual cycle if fertilization does not occur?

  The woman has a period as the uterus lining and egg are released