Fight or flight response inc role of adrenaline

• Autonomic NS + endocrine system work together during stress to produce a fight or flight response.

  The SAM pathway is designed to facilitate with coping with stressful situations and can be life-saving.
• • When someone enters a potentially stressful situation the amygdala is activated. The amygdala responds to sensory input and is involved with processing emotions. If the situation is stressful/dangerous the amygdala sends a distress signal to the hypothalamus which communicates with the body via the sympathetic NS. The hypothalamus activates the SAM (sympathomedullary) pathway which runs to the adrenal medulla and sympathetic NS. The adrenal medulla secretes adrenaline and noradrenaline into the bloodstream which causes physiological changes to the body to prepare for fight and flight.
• • Hypothalamus - region in the brain... activates
  • Sympathetic NS - Peripheral NS, Autonomic NS.... triggers
  • Adrenal Medulla - gland.... secretes
  • Adrenaline + Noradrenaline - hormones.... facilitates
  • Fight or flight response
• 1. person enters stressful/dangerous situations
  2. amygdala sends distress signals to the hypothalamus
  3. hypothalamus activates SAM pathway which runs to the adrenal medulla + sympathetic NS
  4. sympathetic NS stimulates adrenal medulla
  5. adrenal medulla secretes adrenaline + noradrenaline into the bloodstream
  6. adrenaline causes many physiological changes to the body e.g increase heartbeat, breathing rate to prepare body for fight or flight
• Physiological changes -

  Increased heart rate = increased blood flow to organs & increased movement of adrenaline around the body.

  Increased breathing rate = increased oxygen intake

  Pupil dilation = increased light entry into eye which enhances the vision (especially in the dark)

  Sweat production = Regulates temperature

  Reduction of non-essential functions e.g. digestion = more energy for other essential functions.

  Following fight or flight the parasympathetic NS is activated to return the body to its 'normal' state. All functions are reversed.