The Menstrual Cycle & Puberty

• What is the main focus of today's video?

  The reproductive hormones and the menstrual cycle
• What is puberty?


  It is the period during which adolescents develop secondary sexual characteristics
• What are secondary sexual characteristics in men?


  Facial hair
• What hormone triggers puberty in men?


  Testosterone
• Where is testosterone produced in men?


  In the testes
• What hormone is primarily responsible for female puberty?

  Estrogen
• Where is estrogen produced in women?


  In the ovaries
• What are the four stages of the menstrual cycle?

  1. Menstruation
  2. Uterus lining buildup
  3. Ovulation
  4. Maintenance of the uterus lining
• What is the average length of a menstrual cycle?


  Around 28 days
• What does the red line in the menstrual cycle graph represent?


  The thickness of the uterus lining
• What happens during stage one of the menstrual cycle?

  Menstruation occurs, lasting about four days
• What occurs during stage two of the menstrual cycle?


  The uterus lining starts to build up again
• How long does stage two of the menstrual cycle last?


  Around ten days
• What is the purpose of the thick spongy layer formed in stage two?

  To prepare the uterus lining for a fertilized egg
• What is ovulation?


  The release of an egg from one of the ovaries
• How long does stage three of the menstrual cycle last?


  It takes place in a single day
• What happens in stage four of the menstrual cycle?


  The lining of the uterus is maintained
• What occurs if no fertilized egg reaches the uterus?


  The uterus lining starts to break down
• What happens if a fertilized egg implants into the uterus lining?


  The menstrual cycle stops because the woman is pregnant
• What hormones are involved in the menstrual cycle?


  • Estrogen
  • Progesterone
  • Luteinizing hormone (LH)
  • Follicle stimulating hormone (FSH)
• What hormone stimulates the growth of the uterus lining?


  Estrogen
• When does progesterone increase during the menstrual cycle?


  In stage four
• What is the role of progesterone in the menstrual cycle?


  To maintain the lining of the uterus
• Where are LH and FSH produced?


  In the pituitary gland
• What does FSH do in the menstrual cycle?


  It stimulates one of the eggs to mature in the ovaries
• What does LH do during ovulation?


  It stimulates the release of the egg
• How do the hormones interact during the menstrual cycle?

  • FSH stimulates ovaries to produce estrogen
  • Estrogen inhibits FSH (negative feedback)
  • High estrogen levels stimulate LH release
  • Progesterone inhibits both LH and FSH
• What is the effect of high estrogen levels on FSH?


  They inhibit FSH production
• What happens when progesterone levels drop?


  The uterus lining breaks down