Physiological Stress Responses

1
Physiological Stress Responses

• Short term stress response
• The HPAA
• The fight/flight response
• Long term stress response
• The general adaptation syndrome

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2
General Adaptation

• Selye (1936)
• 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

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3
General Adaptation

• 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

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4
General Adaptation

• Exhaustion
• Total depletion of coping resources
• Metabolic changes
• Decline in immune functioning
• Increased susceptibility to infection

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5
General Adaptation
Adrenal Glands become enlarged
Thymus shrinks
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Stomach develops ulcers
6
General Adaptation

• 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

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