Endocrine System

• The endocrine system is composed of glands which secrete chemicals called hormones directly into the bloodstream. The blood carries the hormone to a target organ where it produces an effect
• Compared to the nervous system the effects of the endocrine system are slower but act for longer, the nervous system uses electrical impulses which travel down neurons whilst the endocrine system uses hormones which are carried in the bloodstream
• The pancreas releases hormones that are involved in controlling the concentration of glucose in blood

  
• The ovaries and testes release hormones involved in puberty and in reproduction

  
• The thyroid gland produces hormones which are involved in growth and in regulating the body's basal metabolic rate - how quickly the body's reactions take place

  
• The adrenal glands release adrenaline which is produced in times of fear and stress

  
• The pituitary gland in the brain is a ‘master gland’ which secretes several hormones into the blood in response to body conditions. These hormones in turn act on other glands to stimulate other hormones to be released to bring about effects.