endocrine system

• Endocrine system


  Allows different parts of our body to communicate with each other
• Endocrine system


  Similar job to nervous system, but with lots of differences
• Endocrine system


  • Consists of a series of glands found throughout the body
  • Glands secrete hormones, which are small chemical molecules passed into the blood and spread throughout the body
• Hormones


  Act as signals to trigger certain changes inside cells
• Pituitary gland


  • Produces multiple different hormones
  • Some hormones directly tell the body what to do
  • Some hormones tell other glands to release their own hormones
  • Not actually part of the brain, but attached to it
• Thyroid gland


  • Produces the hormone thyroxine
  • Relates to the rate of our metabolism
  • Plays an important role in growth and development
• Thyroid stimulating hormone (TSH)

  1. Pituitary gland detects low levels of thyroxine

  2. Pituitary gland releases TSH

  3. TSH stimulates the thyroid to produce more thyroxine

  4. Brings the level of thyroxine back up to normal
• Negative feedback


  If thyroxine levels are too low, they are stimulated to rise again, and if they went too high, they are brought back down
• Adrenal glands

  • Produce the hormone adrenaline
  • Normally released during the fight-or-flight response
  • Increases heart rate and gets blood pumping faster
• Pancreas


  • Produces the hormone insulin
  • Helps regulate blood glucose concentrations
• Testes

  • Produce the hormone testosterone
  • Control puberty
  • Produce male gametes (sperm)
• Ovaries


  • Produce the hormone estrogen
  • Influence puberty and the menstrual cycle
  • Hold female gametes (egg cells)
• Endocrine system vs. Nervous system

  • Endocrine system uses hormones (small molecules secreted by glands and transported in the blood)
  • Nervous system uses electrical impulses transferred along nerve cells
  • Hormones spread more slowly and have longer-lasting effects
  • Nerve impulses are sent very fast and have short-lasting effects
  • Hormones act more generally and interact with many different cells
  • Nerve impulses are sent to one specific area