5.7 - Endocrine System

• The Endocrine System:

  • relies on hormones that are secreted by glands
  • transported through blood
  • spread slowly
  • effects last longer
  • act more generally throughout the entire body
• Pituitary Gland:

  • not part of the brain but is up in the skull
  • tells the body what to do
  • ‘Master Gland’
  • tells other glands what to do by secreting hormones
  • Thyroid Stimulating Hormone (TSH) - tells thyroid gland to make more thyroxine
  • ACTH - tells adrenal glands to make more adrenaline
  • Follicle Stimulating Hormone (FSH) - stimulates puberty and gamete production
  • Luteinizing Hormone (LH) - triggers ovulation
• Thyroid Gland:

  • located in the neck
  • produces Thyroxine - regulates rate of metabolism, growth and development
• Adrenal Glands:

  • located above kidneys
  • produces Adrenaline - increases heart rate, ‘fight or flight’
• Pancreas:

  • located in front of kidneys
  • produces Insulin - regulates blood glucose concentration (blood glucose concentration to high)
  • produces glucagon - regulates blood glucose concentration (blood glucose concentration too low)
• Testes:

  • only in males
  • produces Testosterone - controls puberty, sperm production
• Ovaries:

  • only in females
  • produces Oestrogen - controls puberty, menstrual cycle
  • hold gametes (egg cells)
• How the Endocrine System works:

  1. Glands are organs that release small chemicals called hormones
  2. These chemicals are released into the bloodstream, allowing them to travel around the body
  3. They can then bind to specific cells that have the correct receptors
  4. This will bring about change within the cells