Stress Flashcards
Stress as a stimulus
- Focus on the environment
- Event or circumstance is the cause of stress
- Events or circumstances are known as ‘stressors’
Stress as a response
- Focus on individual’s reaction to stressors
- Psychological response
- Physiological response
- Responses are known as ‘strain’
Stress as a transaction
• Focus on stress as a process
• Relationship between the person and environment
• Continuous interactions and adjustments
– ‘transactions’
Stress definition
- feeling of lack of control
- unpredictability
Stress appraisal
Primary and Secondary
• Cognitive appraisal Primary appraisal (danger) Secondary appraisal (coping)
Physiological models of stress
• Fight or flight response (Cannon 1932)
– acute/ short term
• General Adaptation Syndrome (Selye, 1956) – chronic/ long term
Fight or flight response
- Homeostasis threatened, disrupted
- Response to acute, short lived stress
- External threats elicit fight or flight response
- physiological arousal
- Enable fight or flight response and restore homeostasis
- BUT prolonged state of high arousal harmful to health
General Adaptation Syndrome
stressor
alarm - mobilisation to fend off threat
resistance - continued fight against stressor
exhaustion - depletion of resources, ability to resist may collapse
Sympathetic activation
– under stress: sympathetic nervous system stimulated
– catecholamines produced (adrenalin & noradrenalin) – quick response system (within seconds)
• Hypothalamic-pituitary-adrenocortical (HPA) activation
– ed levels of corticosteroids (glucocorticoids e.g. cortisol)
– raised levels of brain opioids beta endorphin & enkephalin
– slower response system (minutes to hours)
Long- term stress response (cortex):
- retention of sodium & water by kidneys
- blood vol, BP
- P, F converted to glucose/ broken down for energy
- blood sugar
- immune system
Short- term stress response (medulla):
- heart rate
- BP
- metabolic rate
- changes in blood flow
- dilation of bronchioles
Typical signs of stress
- biochemical
- physiological
- behavioural
- cognitive
- emotional
Stress and Myocardial Infarction
• Evidence for association between psychosocial stress
and
risk of acute MI
• Effect of stress is:
– independent of SES, smoking
– consistent across geographic regions, in different age groups, and in men and women
• Approaches needed to modify stress factors
Physiological response to stress
– catecholamine & corticosteroid release
– immune cell activity (T and B cells) against antigens
– linked to development of infectious disease, cancer