Ao1

• stage 1

  situation is appraised and perceived as stressful
• stage 2

  the hypothalamus is alerted. it recognises stress is acute so it activates the sympathetic branch of the ANS
• stage 3

  stimulates the adrenal medulla which is part of the adrenal gland - located above the kidneys
• stage 4

  adrenal medulla secretes adrenaline and indirectly the neurotransmitter noradrenaline into bloodstream
• stage 5

  prepares body for fight or flight which causes physiological changes
• Activities occurring to the body when the sympathetic division of the ANS is activated


  increased heart rate

  increased breathing rate

  dilates pupils

  sweating

  inhibits digestion

  flushed face
• increased heart rate reason

  increased blood flow around the body, more oxygen to vital organs
• increased breathing rate reason

  increased oxygen consumption
• dilated pupils reason

  allows more light in to see more potential threats
• sweating reason

  cools down the body
• inhibits digestion reason

  blood flow and oxygen is redirected from digestive processes
• flushed face / pale skin reason

  increased blood flow to brain
• why do these changes facilitate?

  allows more oxygen to the muscles to allow them to work better or allow more oxygen to the brain to allow quicker thinking and problem solving
• Parasympathetic branch

  the body cannot maintain increased level of activity for long periods of time as it takes too much energy

  After a few minutes (or when the stress has been dealt with), the parasympathetic branch of the nervous system is activated

  This is antagonistic to the sympathetic branch and acts as a brake response

  It serves to return the body back to it's normal physiological state