endocrine system

• Gland - an organ in the body that synthesises substances such as hormones.
• Hormones - chemical substances that circulate in the bloodstream and only affect target organs. They are produced in large quantities but disappear quickly. Their effects are very powerful.
• Fight or flight response - the way an animal responds when stressed. The body becomes physiologically aroused in readiness to fight an aggressor or in some cases, flee.
• • Adrenaline a hormone produced by the adrenal glands which is part of the human body’s immediate stress response system. Adrenaline has a strong effect on the cells of the cardiovascular system - stimulating heart rate, contracting blood vessels and dilating air passages. 
• endocrine system works alongside the Nervous System to control vital functions in the body.  It instructs glands to release hormones into the bloodstream which are then carried towards organs, working more slowly than the Nervous System.
• 1. Stressor/threat is perceived by the brain
  2. Hypothalamus in brain is activated
  3. Hypothalamus activates the pituitary gland
  4. Triggers sympathetic branch of Autonomic nervous system
  5. Adrenal gland releases adrenaline from the adrenal medulla, causing body changes such as increased heart rate which creates the physiological arousal necessary for the fight or flight response
  6. Stressor passing is perceived by the brain
  7. Triggers parasympathetic branch of Autonomic nervous system
  8. Returns body to resting state and is sometimes known as the rest and digest response
• hypothalamus stimulates and controls the release of hormones from the pituitary gland
• pituitary gland anterior lobe ACTH stimulates the release of cortisol during stress from the adrenal cortex
• pituitary gland posterior lobe oxyticin stimulates the womb to contract during childbirth
• adrenal gland adrenal medulla adrenaline flight of flight response
• adrenal gland adrenal cortex cortisol stimulates the release of glucose
• ovaries oestrogen regulates reproductive system, and controls the menstrual cycle and pregnancy
• testes testosterone secondary sexual characteristics and maintains muscle growth
• thyroid thyroxine controls metabolism