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 specific 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 happens to eggs in the ovaries once puberty begins?

  They start to mature, and an egg is released every 28 days
• 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 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, resulting in a period
• What are the four key hormones involved in the menstrual cycle?

  • Follicle stimulating hormone (FSH)
  • Luteinizing hormone (LH)
  • Estrogen
  • Progesterone
• What does follicle stimulating hormone (FSH) do?

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

  It causes the egg to be released, triggering ovulation
• What is the function of estrogen in the menstrual cycle?

  It causes the lining of the uterus to become thick and inhibits FSH production
• What are the two effects of progesterone?

  It stops the release of FSH and LH and keeps the uterus lining thick
• What happens to progesterone levels if fertilization does not take place?

  The level of progesterone falls, leading to the release of the uterus lining and the egg
• How do FSH and estrogen interact in the menstrual cycle?

  • FSH is released by the pituitary gland
  • FSH causes an egg to mature and triggers estrogen production
  • Estrogen inhibits FSH production
• How do LH and progesterone interact in the menstrual cycle?

  • LH triggers ovulation
  • After ovulation, the ovary produces progesterone
  • Progesterone prevents the release of FSH and LH
• What happens to the level of FSH during the menstrual cycle?

  It rises initially and then falls due to the increase in estrogen
• What triggers the peak of LH levels in the menstrual cycle?

  The increase in estrogen levels
• What happens to progesterone levels after ovulation?

  Progesterone levels rise after ovulation
• What is the outcome if fertilization does not occur?

  Progesterone levels fall, leading to menstruation