The Endocrine System

• The endocrine system is one of the body’s major information systems that provides a chemical system of communication via the bloodstream. The endocrine system instructs glands to produce and secrete hormones into the bloodstream to regulate the activity of cells and organs in the body, and thus, bodily functions.
• The endocrine system works alongside the nervous system to control vital functions in the body.
• The endocrine system works far slower than the nervous system but its effects are longer lasting.
• What is the pituitary gland?

  This gland is known as the master gland because the hormones released by this gland control and stimulate the release of hormones from other glands.
• What is the pineal gland?

  The pineal gland releases melatonin, it is responsible for important biological rhythms; including the sleep-wake cycle.
• What is the adrenal gland (medulla)?

  The adrenal gland releases adrenaline and noradrenaline which are the key hormones in the "fight or flight" response.
• The “fight or flight" response primes the body and mind for extreme action, fighting for our lives, or escaping a threat and after this event has passed the body returns back to homeostasis.
• When a stressor/threat is recognised, the hypothalamus stimulates the pituitary gland, which activates the adrenal medulla (releases adrenaline & noradrenaline), preparing the body for fight or flight. These hormones circulate the body and cause an increase in heart rate, which pushes more blood to the muscles, heart and other vital organs. Breathing becomes more rapid to increase our intake of oxygen, and these hormones also trigger the release of glucose to support energy for the body for the fight-or-flight response.