1. Physiological Stress Responses
Short term stress response
The HPAA
The fight/flight response
Long term stress response
The general adaptation syndrome

2. Selye and GAS (1956)
General it refers to the belief that there is the same general bodily response to all stressors.
Adaptation refers to his view that the stressor response enables organisms to adapt to stressors
Syndrome means that typical or characteristic combination of factors that make up the stress response

3. Selye (1936) General Adaptation
Rats exposed to a variety of severe but non-lethal stressors
Exercise, injury, mutilation, poisoning 
A long-term response to stress was observed that was independent of stressor type

4. Selye’s work on rats
Selye put rats in unpleasant situations such as having injections, extreme cold and having limbs cut off. He measured there physical stress response and they all responded in the same way. Hence his GAS theory.
He split his theory into 3 stages

5. Stage 1- Alarm reaction
Threat or stressor is recognised the stress response is elicited.
The SAM system goes into action releasing Adrenaline
There is some activation of HPA axis, producing cortisol.

6. Stage 2 Resistance
If stress continues, the body needs to find some way of coping. If the body cannot cope there maybe outward normal appearance but there may be long term changes to the immune system because to the release of cortisol which causes the immune system to be less responsive.

7. Stage 3 Exhaustion Body can no long maintain normal functioning
The initial SAM symptoms reappear
The Peripheral nervous system functions at an abnormally low level an collapse of the body’s immune system. Also how people die of shock.
Results in stress related illness such as high blood pressure, asthma and heart disease.

8. General Adaptation Syndrome recap
Alarm
Immediate response to stressor
Fight or flight
Resistance
Body tries to adapt to stressor
Hormonal changes to cope with stress
Conservation of resources
Effects on activity level, feeding etc.
Not necessarily harmful

9. General Adaptation Exhaustion Total depletion of coping resources
Metabolic changes
Decline in immune functioning
Increased susceptibility to infection

10. General Adaptation Adrenal Glands become enlarged Thymus shrinks
Stomach develops ulcers

11. Evaluating GAS Ethical objections to use of animals
Deliberate infliction of pain & stress
Could alternative methods have been used?
Problems generalising
Rat and human physiology have similarities and differences
Human stress is mediated by psychological factors

12. Evaluation Strengths Based on careful observation
Large amount of research
Identified link between psychological factors and physical illness

13. Evaluation - Weaknesses
Ignores individual – i.e. interpretation of what a stressor is and ability to cope
Work done on rats therefore cannot be generalised to humans
He claimed that all stressors produce the same physiological response. However evidence suggests that there are specific responses to specific stressors (Cox) anxiety more adrenalin and aggression more noradrenalin.