hormones

• What are the two communication systems in the human body?

  Nervous system and endocrine system
• What do hormones do in the body?

  They act as chemical messengers
• What is the role of the pituitary gland?

  It secretes hormones into the blood
• What hormone does the pancreas secrete?

  Insulin
• What does thyroxine control?

  Metabolic rate, heart rate, and temperature
• What hormone is secreted by the adrenal gland?

  Adrenaline
• What is the fight-or-flight response?

  Body's reaction to a dangerous situation
• What happens to heart rate during the fight-or-flight response?

  It increases to supply oxygen quickly
• What does increased blood flow to muscles allow?

  Stronger and quicker muscle contractions
• What does thyroxine regulate?

  Metabolic rate
• How does low thyroxine level affect hormone production?

  It stimulates TRH production in the hypothalamus
• What is the role of negative feedback in thyroxine regulation?

  It maintains normal thyroxine levels
• What initiates the menstrual cycle?

  Breaking down of the uterine lining
• What occurs during ovulation?

  An egg is released from the ovary
• What hormone causes egg maturation in the ovary?

  Follicle stimulating hormone (FSH)
• What does oestrogen do during the menstrual cycle?

  Stimulates uterine lining growth
• What hormone is responsible for ovulation?

  Luteinising hormone (LH)
• What is the role of progesterone in the menstrual cycle?

  Maintains the uterine lining
• What are the hormonal methods of contraception?

  • Contraceptive pill (mixed and progesterone only)
  • Contraceptive patch
  • Contraceptive implant
  • Contraceptive injection
  • Plastic intrauterine device (IUD)
• What does the mixed contraceptive pill contain?

  Oestrogen and progesterone
• What is a side effect of the mixed contraceptive pill?

  Mood swings and breast tenderness
• How long does the contraceptive patch last?

  1 week
• What is the function of the contraceptive implant?

  Releases continuous progesterone
• How long does the contraceptive implant last?

  3 years
• What is the effect of the contraceptive injection?

  Same as the implant
• How long does the contraceptive injection last?

  2 to 3 months
• What does the plastic IUD do?

  Kills sperm and prevents implantation
• How long does the plastic IUD last?

  5 to 10 years
• What are non-hormonal methods of contraception?

  • Chemical methods (spermicides)
  • Barrier methods (condoms, diaphragms)
  • Copper intrauterine device
  • Surgical methods (sterilisation)
  • Abstaining from intercourse
• What is the role of spermicides?

  They kill or disable sperm
• What is a disadvantage of condoms?

  They can tear and let sperm through
• What does a diaphragm do?

  Covers the cervix and is used with spermicide
• What does the copper IUD do?

  Kills sperm and prevents implantation
• What is the purpose of male and female sterilisation?

  To cut and tie fallopian tubes or sperm duct
• What is homeostasis?

  Maintenance of a constant internal environment
• Why is homeostasis important?

  It maintains enzyme action and cell functions
• What three factors does homeostasis control?

  Blood glucose, body temperature, water levels
• What are the components of control systems in homeostasis?

  Receptors, coordination centres, effectors
• Where is the thermoregulatory centre located?

  In the hypothalamus of the brain
• What happens if body temperature exceeds 37 degrees Celsius?

  Enzymes become less effective and denature