Stress

Stress is the lack of balance between the perceived demands of a situation and perceived abilities to cope with such demands.

Sympathomedullary pathway:

-          The hypothalamus activates the sympathetic nervous system, which then stimulates the adrenal medulla to release the hormones adrenaline and noradrenaline into the bloodstream.

-          This gets the body ready for fight-or-flight, e.g. increase blood pressure and heart rate.

Effects:

Pupils dilate

Breathing rate increases

Heart pumps harder and faster

Blood supply to the legs increase

Shuts of your digestive and reproductive systems

Adrenaline is released from the adrenal glands on the kidney

Pituitary-adrenal system:

-          The hypothalamus communicates with the pituitary gland causing it to release ACTH

-           This hormone is then detected in the bloodstream by the adrenal cortex, which then releases corticosteroids such as cortisol and corticosterone.

-          The corticosteroids have a range of effects such as causing the liver to release glucose.

Research into stress related illness:

Kiecolt-Glaser (1984):

-          Took blood samples from students sitting stressful examinations and asked them to complete questionnaires and found increased immunosuppression.

-          This implies that stress is linked to decreased immune system functioning especially in individuals exposed to certain types of stressor.

Cohen et al (1993):

-          Participants were exposed to the cold virus; those with high stress scores were more likely to develop the cold.

-          This suggests that stress decreases the efficiency of the immune system, creating a greater vulnerability to illness.

Kiecolt-Glaser et al (1995):

-          Slight wounds were given to female participants, participants who had the stress of caring for senile parents took longer to heal that those without such stressors.

-          This suggests that prolonged chronic stress reduces immune system function.

Riley (1981):

-          Placed mice on a rotating turntable and counted the mice’s lymphocyte over a five-hour period and found that their immune system response was suppressed.

-          He then implanted cancer cells into the mice and a group of mice that had 10 minutes of rotation per hour for 3 days, developed large tumours.

-          This suggests that stress does impact the immune system.

-          Most research linked to stress weakening the immune system function is correlational and so does not indicate causality

-          Time lag for stress-related changes to take their toll

-          Findings gained from the research can be used by healthy practitioners to predict problems relating to stress and suggest appropriate coping strategies and therapies

-          Unethical to intentionally stress humans/mice out

Research into life changes as sources of stress:

Holmes and Rahe (1967):

-          Examined medical records of 5,000 patients, finding 43 common life changes which occurred prior to onset of illness. The life events were given ratings on how stressful they were perceived by 100 judges. Individuals which had high LCU scores of over 300 had an 805 chance of developing illnesses like diabetes, heart conditions and cancer.

-          This suggests that it…