The Menstrual Cycle

• What is the endocrine system responsible for?

  Releasing hormones into the bloodstream
• What hormone do the testes produce?

  Testosterone
• What does testosterone stimulate in men?

  Production of sperm
• What hormone do the ovaries produce?

  Estrogen
• What happens to eggs in the ovaries after puberty?

  They start to mature
• What is ovulation?

  Release of an egg from the ovary
• What occurs if the egg is fertilized?

  It can implant into the uterus wall
• What happens if the egg is not fertilized?

  The egg and uterus lining are released
• What are the four key hormones in the menstrual cycle?

  • Follicle stimulating hormone (FSH)
  • Luteinizing hormone (LH)
  • Estrogen
  • Progesterone
• What does FSH do in the menstrual cycle?

  Causes an egg to mature in the ovary
• What is the role of LH in the menstrual cycle?

  Causes the egg to be released
• What do estrogen and progesterone do?

  Maintain the uterus lining for implantation
• What happens to FSH when estrogen levels rise?

  Production of FSH is inhibited
• What triggers ovulation?

  Release of luteinizing hormone (LH)
• What does progesterone do after ovulation?

  Prevents release of FSH and LH
• What happens to progesterone levels if fertilization does not occur?

  Progesterone levels fall
• How do FSH and LH levels change during the menstrual cycle?

  FSH rises, then falls; LH peaks at ovulation
• What is the significance of the menstrual cycle?

  It prepares the body for potential pregnancy
• What are the interactions of hormones during the menstrual cycle?

  1. FSH stimulates egg maturation and estrogen production.
  2. Estrogen inhibits FSH and triggers LH release.
  3. LH triggers ovulation and stimulates progesterone production.
  4. Progesterone inhibits FSH and LH, maintaining the uterus lining.
  5. If no fertilization occurs, progesterone levels fall, leading to menstruation.
• What can you be asked to interpret in an exam regarding reproductive hormones?

  Graphs of hormone levels during the menstrual cycle
• What happens to the uterus lining during the menstrual cycle?

  It thickens in preparation for implantation
• What is the duration of the menstrual cycle?

  28 days