2. Stress Responses - Fight/Flight

• 1. Stress Responses - Fight/Flight

  Short-term Stress:

  • events mediated by ‘sympathomeduallary pathway’ (SAM).
• 2. Stress Responses - Fight/Flight

  Endocrine + ANS, stressful event:

  1. stress = hypothalamus triggers activity in sympathetic n.s. of ANS.
  2. ANS changes from parasympathetic state (resting) to psychologically aroused, sympathetic state.
  3. pituitary gland releases ACTH, produce adrenaline.
• 2a. Stress Responses - Fight/Flight

  Endocrine + ANS, stressful event:

  4. adrenal medulla releases adrenaline into blood.

  5. adrenaline triggers changes in body, arousal necessary for fight/flight.

  6. parasympathetic n.s. returns body to resting state = ’rest and digest’.
• 3. Stress Responses - Fight/Flight

  Sympathetic State:

  • increase heart-rate.
  • increase breathing.
  • inhibits digestion.

  Parasympathetic State:

  • decrease heart-rate.
  • decrease breathing.
  • stimulates digestion.
• 4. Stress Responses - Fight/Flight

  Chronic Stress:

  • if stress continue after fight/flight, 2nd response.
  • HPA axis (hypothalamus, pituitary adrenal).
  • hypothalamus releases CRH into blood.
  • pituitary; CRH causes ATCH release - travel to adrenal glands.
• 5. Stress Responses - Fight/Flight

  Adrenal Glands:

  • cortisol (stress response).
• Stress Responses - Fight/Flight (Evaluation)

  Limitation:

  P - gender differences in f/f response.

  E - women, ‘tend + befriend‘ (Taylor, 2000); tend to young by nurturing + befriending others for protection.

  E - SRY gene on Y chromosome directs male development (aggression/‘fight’); no SRY combined w/ oxytocin + oestrogen prevents response in female (Lee et al).

  L - alpha bias (feminist argument), but due Taylor’s support may be beta bias.
• Stress Responses - Fight/Flight (Evaluation)


  Limitation:

  P - not just fight/flight, but ’freeze’ too (Gray, 1988).

  E - avoid confrontation.

  L - animals/humans display freeze, alert to danger.