Endocrine System

• What points should be mentioned in an overview of the endocrine system?

  • comprised of glands throughout the body & brain
  • glands release hormones (chemical messengers) into the bloodstream
  • endocrine system maintains homeostasis to suit the situation
  • endocrine system is slower than the nervous system but the effect is more widespread
  • high levels of hormones can cause dysfunctions (e.g. Cushing's syndrome)
• Where is the hypothalamus found?

  in the brain
• What is the function of the hypothalamus?

  • the control system which regulates the endocrine system
  • responsible for stimulating/controlling release of hormones from pituitary gland
• Where is the pituitary gland?

  in the brain
• What is the function of the pituitary gland?

  • known as 'master gland'
  • releases hormones which tells other glands to release their hormones
• What is the pituitary gland comprised of?

  Anterior pituitary and posterior pituitary lobes.
• What hormones does the anterior pituitary lobe release?

  • adrenocortical topic hormone (ACTH)
  • gonadotropic hormone
• What is the function of the hormones the anterior pituitary lobe releases?

  • ACTH - stimulates the adrenal cortex to release cortisol
  • gonadotropic - stimulates release of hormones from ovaries (oestrogen & progesterone) & testes (testosterone)
• What does the posterior pituitary lobe do?

  releases oxytocin which is responsible for uterus contractions and bonding (love hormone)
• Where is the pineal gland located?

  in the brain
• What is the function of the pineal gland?

  releases melatonin which regulates the wake-sleep cycle (makes you feel sleepy)
• Where is the thyroid gland located?

  in the neck
• What is the function of the thyroid gland?

  releases thyroxine (T4) which regulates metabolism (food -> energy)
• What is the function of the pancreas?

  releases insulin + glucagon which regulates blood sugar levels
• What does insulin do?

  converts glucose into glycogen to reduce blood sugar levels
• What does glucagon do?

  converts glycogen into glucose to increase blood sugar levels
• Where is the adrenal gland located?

  Above the kidneys
• What is the adrenal gland comprised of?

  Adrenal Cortex (Cortisol) and adrenal Medulla (Middle)
• What does the adrenal medulla do?

  releases adrenaline
• What does the adrenal cortex do?

  releases cortisol
• What is the role of cortisol?

  stimulates the release of glucose while suppressing the immune system
• When is cortisol released?

  after adrenaline in 'fight or flight'
• What is the function of the testes?

  • releases testosterone
  • for growth/development of male reproductive organs
  • secondary sexual characteristics (e.g. facial hair, deepening voice)
• What is the function of the ovaries?

  • releases oestrogen and progesterone
  • growth/development of female reproductive organs
  • secondary sexual characteristics (e.g. breasts, widened hips)
  • regulation of menstrual cycle