G.A.S. refers to the general adaptation syndrome, which describes the body's response to stress in three stages. Stage 1 involves an initial shock response, followed by activation of the sympathetic nervous system. Stage 2 is resistance, where stress hormones remain high and immune function is compromised. If the stressor persists to Stage 3 of exhaustion, resistance is lowered, leaving the body vulnerable to illness and disease. The G.A.S. model examines how psychological stressors tax the body's defense systems and can impact long-term physiological health if stress is not mitigated.

1. G.A.S means the total mobilisation of an organisms resources &
defence systems to meet situations of severe stress.

2. Stage 1a: Alarm – Shock - key points
• When we first become aware of stressor – we go into shock
• E.g. we start walking across the road and without warning a car is
tooting us as it comes towards us – or – you get a text message that
Dad has had a car accident and is in hospital
• The body reacts as if it is injured e.g. Body temp lowered, blood
pressure decreases, muscles are relaxed (loss of tone) etc
• Level of resistance is briefly lowered (we are not yet dealing with
the stressor)

3. Stage 1b: Alarm – Countershock - key points
• Now we start dealing with the stressor
• We become aroused – thus more alert & the sympathetic nervous
system is activated (during c/shock)
• Stress hormones are released into the blood stream - thus heart
rate increases, the respiratory system accelerates – providing the
muscles with more energy/ oxygen – similar to the fight-flight
response
• Level of resistance is raised (meaning we are ready to deal with the
stressor)

4. Stage 2: Resistance- key points
• If the stressor hasn’t been successfully dealt with (during
countershock), we move into the resistance stage
• Physiological arousal remains high, thus the hormones: Adrenalin &
cortisol are released into the bloodstream to energise the body &
repair damaged – but this comes at a cost (see next slide)
• Other physiological functions that are not essential for survival are
shut down e.g. digestion, bowel movements – thus energy is
diverted to the parts of the body that really need it to deal with
stressor

5. Stage 2: Resistance- continued
• The cost of this sustained resistance is that body’s
immune (defence) system is weakened
• Thus we become vulnerable to disease/ illness
• So we might develop symptoms – sore throat, headache,
etc
• Key point the body’s resistance remains at a high level

6. Stage 3: Exhaustion
• If the stressor is not successfully dealt with during
resistance – we enter the exhaustion stage
• The body becomes vulnerable to mental disorders,
psychosomatic diseases, as well as physical disorders such
as hypertension, ulcers, sleep disorders
• Resistance is lowered (due to depletion of immune
system)

7. GAS – key points
• Resistance is high: During countershock/ resistance
• Resistance is low: During shock/ exhaustion
• Fight flight response 1st activated: During
countershock
• Cortisol released: During resistance
• Symptoms developed (sore throat): During resistance
• Illness: During exhaustion
• Strength: the model examined the relationship
between psychological stressors and our defense
systems and our consequential physiological health
• Weaknesses: Didn’t factor cognitive appraisal (as
opposed to transactional model)