endocrine system

• define endocrine system

  network of glands which secretes chemical messengers
• define hormone

  chemicals that circulate in bloodstream and carried to target sites
• what is the function of hormones?

  excites or stimulates a particular body part

  • only effects target cells
  • target cells receives hormones via receptors
• define glands

  organ that synthesises substances
• what's the function of glands?

  produce and secrete hormones

  • hypothalamus signals target gland to increase hormone level
  • when levels are reached, hypothalamus shuts down
• what is the endocrine system regulated by?

  hypothalamus
• what is the major endocrine gland?

  pituitary gland
• outline the function of the pituitary gland

  controlled by the hypothalamus

  • "master" gland
  • produces hormones that are sent in bloodstream and received by target cells
• what are the 2 parts of the pituitary gland?

  1. anterior gland
  2. posterior gland
• outline the role of the anterior gland

  • produces ACTH which stimulates adrenal gland to produce cortisol
  • produces LH and FSH for reproductive functioning
• outline the role of the posterior gland

  • produces oxytocin to facilitate childbirth
• where is the adrenal gland?

  on top of kidneys
• outline the function of adrenal glands

  release hormones that effect metabolism, immune system and stress responses
• what are the 2 parts of the adrenal gland?

  1. adrenal cortex
  2. adrenal medulla
• what's the role of the adrenal cortex?

  releases hormones that are necessary for life

  • cortisol - response to stress
  • aldosterone - maintains blood pressure
• what's the role of the adrenal medulla?

  production of noradrenaline and adrenaline

  • noradrenaline - constricts blood vessels and increase blood pressure
  • adrenaline - increases heart rate and blood flow to muscles and brain
• what's the role of the ovaries?

  responsible for production of progesterone and oestrogen

  • progesterone - menstrual cycle and pregnancy
  • oestrogen - female characteristics
• what's the role of testes?

  produce testosterone for development of facial hair, deep voice and growth

  • controlled by hypothalamus and pituitary gland