the endocrine system

• Endocrine system

  The network of glands that manufacture and secrete hormones
• Endocrine glands are all over the body including the brain
• Endocrine glands

  Specialised groups of cells whose job it is to produce and secrete hormones
• Gland

  Cells clumped together form a structure called a gland that releases chemical messengers called hormones into the bloodstream
• Hormone

  Chemical messengers that travel through the bloodstream influencing many different processes
• Components of the endocrine system

  • Hypothalamus
  • Pituitary gland
  • Adrenal gland
  • Ovary
  • Testis
• Hypothalamus

  Region of the brain controlling pituitary gland
• 
  

  negative feedback is when High levels of hormones from other glands can stop the hypothalamus and pituitary from releasing more of their own hormones

• Pituitary gland

  Known as the master gland; primary function is to influence the release of hormones from all other glands which in turn regulates functions
• Parts of the pituitary gland

  • Anterior
  • Posterior
• ACTH

  Acts as a messenger activating other glands and stimulates adrenal glands to produce cortisol
• LH and FSH

  Hormones that stimulate ovaries to produce oestrogen and progesterone in women and testes to produce testosterone and sperm in men
• Oxytocin

  released by posterior pituitary gland and Stimulates uterus contraction during childbirth
• Target cells

  Have receptor cells that respond to specific hormones
• Adrenal gland

  Made up of two distinct parts: adrenal cortex and adrenal medulla
• Adrenal cortex


  Produces cortisol which regulates and supports a variety of bodily functions
• Cortisol

  Regulates low blood pressure, poor immune function, and inability to deal with stress
• Adrenal medulla

  Produces adrenaline and noradrenaline needed for fight or flight
• Adrenaline

  Helps body respond to stressful situations by increasing heart rate and blood flow to muscles and brain (to speed up conversion rate of glycogen for energy)
• Noradrenaline

  Constricts blood vessels and increases blood pressure
• Ovary

  Part of the female reproductive system responsible for egg production and secretes the hormones oestrogen and progesterone
• Testis

  Secretes the hormone testosterone
• Testosterone

  Causes development of male characteristics, sex drive, maintains muscle strength, and sperm production
• The anterior pituitary gland produces LH and FSH and ACTH
• low cortisol levels cause low blood pressure, poor immune function and inability to cope with stress