Hypothalamus acitivates adrenal medulla (part of the ANS)
Adrenal medulla secretes hormone adrenaline and neurotransmitter noradrenaline
Adrenaline activates fight/flight response
Adrenaline leads to arousal of sympathetic nervous system and decreased arousal of parasympathetic nervous system
Adrenaline: increased heart rate, blood pressure
Parasympathetic branch brings body back to normal state
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Pituitary Adrenal System
Bodys response to long term stress
Hypothalamus releases corticotrophin factor (CRF)
CRF is sent to the pituitary gland which releases adrenocorticotrophic hormone
ACH is sent to adrenal cortex which releases cortisol
Maintains a steady supply of glucose (energy) and surpresses immune system
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Immune System
Specific immunity: B lymphocytes produce antibodies to destroy antigen on surface of pathogen
Non-specific: cells engulf pathogen through phagocytosis to combat infection
Immune surpression: corticosteroids released as part of the pituitary adrenal system causes immunosurpression (fewer white blood cells and therefore fewer antibodies)
Long term stress can lead the body to become vulnerable to infection and disease
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Short Term Stress Study: KIECOLT AND GLASER
Took blood samples from 75 students one month before and during exam period
Blood samples from before exam period had more T-cells than sample after exam period, showing that stress had an impact on the immune system (less effective)
AO2: natural study so high ecological validity yet hard to control extraneous variables EG diet, sleep patterns, age
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Long Term Stress Study: KIECOLT GLASER
Blister wounds on married couples healed slower after a conflicting converstion, showing that the immune system had become less effective after a stressful situation
Poorer immune ststem functionning in women who were separated from their partner than in married couples
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Evaluation of Stress and Immune System
Stress can enhance immune system functionning- EVANS ET AL found antibody activity in students increased with short term acute stress (giving a presentation) however during exams (long term) immune system functionning decreased
Mediating factors also affect stress: lifestyle, social support, personality (A/B)
Health is slow to change and so it is hard to measure long term stress and health changes, reducing validity
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Work Place Stress
Karsek's Job Strain Model
Stress is highest with low job control and high psychological demands
MARMOT ET AL- studied 10,000 civil servants aged 35-65 over 3 year period (longitudinal)
Job control was measured through self report (subjective and demand characteristics)
Correlational analysis showed that workers with job control were 4X more likely to die of a heart attack and have stress related illness
JOHANSSON- Swedish Saw Mill
Studied 14 low control employees and compared them with 10 low stress high control employees
Measured adrenaline and noradrenaline hormones through urine samples throughout the day (objective and so high validity)
RLA- high demand and low control work results in highest levels of stress (and subsequently more vulnerablle to illness, and so suggested job rotation to reduce stress in the workplace
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