11.4.2 Hormones, Puberty and menstrual cycle

• What is a hormone?

  A chemical produced by a gland
• How are hormones broken down in the body?

  They are broken down by the liver
• What is the main male sex hormone?

  Testosterone
• What does testosterone control?

  Development of male secondary sexual characteristics
• What is the main female sex hormone?

  Oestrogen
• What does oestrogen control?

  Development of female secondary sexual characteristics
• What is puberty?

  Stage when a child's body develops into an adult's
• When does puberty typically occur?

  Between ages 10 and 16
• What are the secondary sexual characteristics in females?

  • Development of breasts
  • Widening of hips
  • Menstruation begins
  • Growth of body hair
• What are the secondary sexual characteristics in males?

  • Deepening of voice
  • Growth of facial hair
  • Increased muscle mass
  • Growth of body hair
• What emotional changes occur during puberty?

  Increased interest in sex and mood swings
• What age range is a woman fertile?

  Ages 12 to 50
• What happens during the menstrual cycle?

  The uterus lining prepares for pregnancy

  
• How long does the menstrual cycle usually last?

  Approximately 28 days

  
• What marks the first day of the menstrual cycle?

  The first day of menstruation
• How long does menstruation typically last?

  3 to 7 days
• What happens to the uterus lining after menstruation?

  It builds up again in preparation for pregnancy

  
• What is ovulation?

  Release of an egg from a follicle
• When does ovulation typically occur in the cycle?

  Around day 14 of the cycle
• What happens if the egg is fertilised?

  The lining of the uterus is maintained
• What happens if the egg is not fertilised?

  The lining of the uterus breaks down
• What hormones control the menstrual cycle?

  • FSH (Follicle Stimulating Hormone)
  • Oestrogen
  • LH (Luteinizing Hormone)
  • Progesterone

  
• Where is FSH produced?

  Pituitary gland in the brain

  
• What is the function of FSH?

  Stimulates follicle development and egg maturation

  
• Where is oestrogen produced?

  Follicles in the ovaries
• What does oestrogen do to the uterus lining?

  Repairs and thickens the lining

  
• What hormone triggers ovulation?

  LH (Luteinizing Hormone)
• What is the function of progesterone?

  Maintains the lining of the uterus
• What happens when progesterone levels fall?

  The lining of the uterus breaks down

  
• What does the placenta produce if a woman becomes pregnant?

  Progesterone
• What is the function of the combined contraceptive pill?

  • Contains oestrogen and progesterone
  • Taken for 21 days, followed by a 7-day break
  • Inhibits FSH and LH release
  • Prevents egg maturation and ovulation

  
• What occurs during the 7-day break of the contraceptive pill?

  The woman experiences menstruation
• What does the combined contraceptive pill inhibit?

  Release of FSH and LH
• How does the combined contraceptive pill prevent ovulation?

  By inhibiting LH release from the pituitary gland