fight or flight

• Fight or flight response


  An evolutionary survival mechanism in response to a threat. It primes the body and mind for extreme action, such as fighting for our life or escaping a threat. The body returns to homeostasis after the threat has passed.
• Step 1 of Fight or flight

  A person enters a stressful/dangerous situation.
• Step 2 of Fight or flight

  The amygdala is activated which sends a distress signal to the hypothalamus.
• Step 3 of Fight or flight

  The hypothalamus activates the SAM pathway - pathway running to the adrenal medulla and the sympathetic nervous system.
• Step 4 of Fight or flight

  The sympathetic nervous system stimulates the adrenal medulla, part of the adrenal gland.
• Step 5 of Fight or flight

  The adrenal medulla secretes the hormones adrenaline and noradrenaline into the blood stream.
• Step 6 of Fight or flight

  Adrenaline causes a number of physiological changes to prepare the body for fight or flight - e.g. increased heart rate, increased breathing and blood pressure.
• Step 7 of Fight or flight

  After the fight or flight response, the parasympathetic nervous system is activated to return the body back to its 'normal' resting state e.g. slows down heart rate, breathing rate and reduces blood presure.
• Types of stressors

  • Acute stressors (short-lasting, sudden)
  • Chronic stressors (long-lasting)
• Effects of adrenaline

  • Increased heart rate to push blood to the muscles, heart and other organs.
  • Increased blood pressure
  • Rapid breathing - to take in as much oxygen as possible.
  • Release of glucose and fats - supplying energy to parts of the body.
• Response to chronic (ongoing) stressors


  The brain continues to perceive something as threatening.

  As the initial surge of adrenaline subsides, the hypothalamus activates a stress response called the HPA axis (provides energy for an extended period of time).
• / Females may display a different pattern to males


  E - Taylor et al: behavioural responses to stress are more characterised by a pattern of tend and befriend than fight or flight - this involves protecting themselves and their young through nurturing behaviours.

  E - Women may have a completely different system for coping with stress due to their responses as a primary caregiver.

  L - Therefore, the explanation of fight or flight might not be generalisable to women and even shows beta bias.
• / Contradictory evidence against first phase of reaction to threat


  E - Gray: argues that the first response to danger is to avoid confrontation altogether, so we freeze - most animals display this response.

  E - Shows that there are alternative ways that people may respond to a stressful situation, as shown in animals.

  L - Therefore, the fight of flight response might not fully explain all stress responses that people experience.
• / Genetic basis to sex differences in fight or flight


  E - Lee and Harley: the SRY gene directs male development by promoting aggression and resulting in the fight or flight response to stress.

  E - Suggests the gene may cause males to respond this way by the release of hormones like adrenaline. The absence of the gene in females may prevent the stress response.

  L - Therefore, this shows that gender differences may result in different fight or flight responses.
• / Negative consequences of the fight or flight response


  E -They may be problems for humans if the stress response in repeatedly activated - increased blood pressure can lead to physical damage in blood vessels leading to heart disease.

  E - This shows that the physiological effects of the fight or flight response may lead to negative consequences.

  L - Therefore, this shows negative implications into the fight or flight response.