Function of the endocrine system: glands + hormones

• Endocrine system is an internal communication system formed of a network of glands that secrete hormones into the bloodstream. These hormones regulate bodily functions, cells and organs. They use blood vessels and the bloodstream.

  • Oestrogen - development of the female reproductive system
  • Melatonin - biological clock, regulates sleep
  • Ghrelin - stimulates hunger
  • Adrenaline - prepares body for fight or flight
  • Growth hormone
  • Testosterone - responsible for sex drive, development of sex organs and changes during puberty.
• Pineal gland


  Secretes melatonin, regulates biological rhythms e.g. sleep-wake cycle
• Thyroid & parathyroid


  Secretes thyroxine, regulates metabolism
• Ovaries/Testes

  Secrete oestrogen/testosterone, reproductive system growth, puberty etc.
• Hypothalamus


  Stimulates and controls release of hormones from pituitary gland
• Pituitary gland


  Master gland, stimulates release of hormones from other glands
• Adrenal gland (medulla)


  Secretes adrenaline & noradrenaline, key hormone in fight or flight
• Adrenal gland (cortex)


  Secretes cortisol and release of glucose to provide body with energy while supressing immune system
• Outline the function of the endocrine system, gland + hormone.

  • the endocrine system helps to regulate the activity of cells and organs in the body
  • the endocrine system communicates chemical messages to the organs of the body
  • the thyroid gland produces thyroxine, which increases heart rate and metabolic rates
  • the pineal gland produces melatonin, which may help regulate the wake-sleep cycle
  • the pancreas secretes insulin and glucagon, which help regulate blood sugar levels.