B3.4 Endocrine system

• What is the primary function of the endocrine system?

  To allow body parts to communicate
• How does the endocrine system differ from the nervous system?

  It uses hormones instead of electrical impulses
• What do glands in the endocrine system secrete?

  Hormones
• What are hormones?

  Small chemical molecules in the blood
• Why do only some tissues respond to hormones?

  Only some have specific receptors for hormones
• What are the main glands in the endocrine system?

  • Pituitary gland
  • Thyroid gland
  • Adrenal glands
  • Pancreas
  • Testes
  • Ovaries
• What is the pituitary gland often called?

  The master gland
• What does the pituitary gland produce?

  Multiple different hormones
• What is the role of thyroxine produced by the thyroid gland?

  Regulates metabolism and growth
• What triggers the release of thyroid stimulating hormone (TSH)?

  Low levels of thyroxine detected
• What is the feedback process called when thyroxine levels are regulated?

  Negative feedback
• What hormone do the adrenal glands produce?

  Adrenaline
• When is adrenaline typically released?

  During the fight-or-flight response
• What is the function of insulin produced by the pancreas?

  Regulates blood glucose concentrations
• What hormone do the testes produce?

  Testosterone
• What are the main roles of testosterone?

  Controls puberty and produces sperm
• What hormone do the ovaries produce?

  Estrogen
• What are the main roles of estrogen?

  Influences puberty and menstrual cycle
• How do hormones spread through the body compared to nerve impulses?

  Hormones spread slowly; nerve impulses are fast
• What is the duration of effects from hormones compared to nerve impulses?

  Hormonal effects last longer than nerve impulses
• How are the areas of effect different between hormones and nerve impulses?

  Hormones affect many cells; nerve impulses are specific
• Why is the nervous system described as precise?

  It sends impulses to specific areas
• How the endocrine system works:

  1. Glands are organs that release small chemicals called hormones.
  2. These chemicals are normally 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 some change within the cells.
• True or false? A hormone can only stimulate specific types of cells.

  True, A hormone can only stimulate a cell if the cell has the correct receptor for that hormone. 
• Different glands release different hormones.


  True
• Which three of the following statements are true, regarding the the pituitary gland?

  • It releases multiple hormones 
  • It releases multiple hormones 
  • The hormones it releases control what other glands do
• Which gland releases thyroxine? 

  Thyroid
• What is the role of thyroxine?

   It regulates metabolism 

  Thyroxine regulates your metabolic rate. Too much thyroxine will increase your metabolic rate. 
• If the level of thyroxine in the blood is too ___ , the pituitary gland will release more thyroid stimulating hormone (TSH). 


  Low
• What is the role of adrenaline? 

  Stimulates fight or flight response (higher heart rate etc)
• Which organ is adrenaline released from? 

  Adrenal glands 
• Which organ is insulin released from? 

  Pancreas 
• Name 2 sex hormones that stimulate puberty

  • Testosterone
  • Oestrogen
• Which organ is testosterone released from? 

  Testes
• Do the effects of the endocrine system or the nervous system last longer?

  Endocrine, The effects of the endocrine system last longer as the hormones stay in blood for long time (often hours). In contrast, electrical impulses from the nervous system only last a split second.