Fight or Flight Response

• when does the fight or flight response occur?

  when a threat is perceived or we are put into a stressful situation (acute stress).
• what is the fight or flight response?

  • a survival mechanism & therefore is an adaptive trait.
  • automatic response that the body goes through in order for us to either:

  stay & face the threat- fight.

  run away- flight.
• what does the body rely on?

  the role of the autonomic nervous system and the endocrine system to action this.
• the sympathomedullary pathway (SAM):

  • is a bodily system designed to facilitate coping w/acutely stressful situations.
  • it's a process within the sympathetic branch of the autonomic nervous system & the end result is the release of adrenaline (endocrine system) which aids the fight or flight response.
• draw the process:

  draw it NOW:

  
• some examples from SNS (sympathetic nervous system):

  • increased heart rate- to increase blood flow to organs & increase the movement of adrenaline around the body.
  • increased breathing rate- to increase oxygen intake.
  • pupil dialation- to increase light entry into the eye & enhance vision (especially in the dark).
  • sweat production- to regulate temp.
  • reduction of non-essential functions (e.g. digestive system, urination, salivation)- to increase energy for other essential items.
• role of the parasympathetic NS:

  • following fight or flight response, the PSNS is activated to return the body back to its 'normal' resting state- homeostasis.
  • consequently, PSNS has the opposite effect on our body- slowing down functions that were accelerated & activating other functions that were inhibited.
• chronic stress:

  response to chronic (ongoing stressors):

  • if the brain continues to perceive something as threatening, the 2nd system kicks in.
  • as the initial surge of adrenaline subsides, the hypothalamus activates a stress response system called the HPA axis.
  • this consists of the hypothalamus, the pituitary gland & the adrenal glands.
• chronic stress (continued):

  • 'H', the hypothalamus- in response to continued threat, the hypothalamus releases a chemical messenger (CRH), which released into the bloodstream in response to the stressor.
  • 'P', the pituitary gland- on arrival at the pituitary gland, CRH causes the pituitary to produce & release ACTH. it's transported in the bloodstream to its target gland.
• 'A'- the adrenal glands:

  • ACTH stimulates the adrenal cortex to release various stress-related hormones, including cortisol. cortisol is responsible for several effects in the body that are important in the fight-or-flight response.
  • some of these are positive (e.g. quick burst of energy and a lower sensitivity to pain) whereas others are negative (e.g. impaired cognitive performance & lowered immune response).
• long-term effects of prolonged exposure to the stress response (chronic stress)- AO3:

  can be physically & psychologically damaging:

  • heart disease
  • problems w/digestion
  • increased blood pressure
  • anxiety
  • sleep deprivation

  this is a negative consequence of the fight/flight response. this can be used to evalauate the response.
• coping w/stress (strength):

  learning to reframe the physiological signs of the fight-or-flight response (e.g. increased heart rate & pupil dialation) as signs of arousal & energy, rather than fear can lead to a more adaptive response to stressful situations.
• adaptive response to danger (strength):

  heightened senses & focus provided by the response makes individuals more aware of potential threats, increasing their chances of detecting & avoiding dangers.
• taylor et al. (2000)- weakness:

  P- females behavioural responses to stress are more characterised by a pattern of 'tend & befriend' than fight or flight.

  E- involves protecting themselves & their young through nurturing behaviours (tending) & forming protective alliances w/other women (befriending).

  E- women may have a different system for coping w/stress because their responses evolved in the context of being the primary caregiver of their children.

  L- therefore, theory ignores gender differences (androcentric), difficult to generalise to women & how they cope w/stress.
• gray (1988)- weakness:

  P- the 1st phase of reaction to a threat is not to fight or flee, but to avoid confrontation.

  E- prior to responding w/attacking or running away most animals, including humans, display the 'freeze response'.

  E- the adaptive advantages of this response for 'freezing' focuses attention & makes them lack for new info to make the best response for that particular threat.

  L- another explanation for fight-or-flight response, weakening the theory.
• lee & harley (2012)- weakness:

  P- there is a genetic basis for gender differences in the fight-or-flight response.

  E- SRY gene, found male y chromosome, directs male development, promoting aggression & resulting in the fight or flight response to stress.

  E- on the the other hand, absence of SRY gene in females, together w/the action of oestrogen & oxytocin may prevent this response to stress.

  L- therefore, there is a genetic gender difference in regards to fight-or-flight response.
• flow chart of nervous system (acute stressors) and endocrine system (chronic stressors):

  draw it NOW: