Stress is the biological and psychological responses experienced on encountering a threat that we feel we do not have the resources to deal with.
A stressor is anything that set off a stress response.
The stress response can react in either one of two ways, the Pituitary-Adrenal Pathway or the sympathomedullary pathway.
Pituitary- Adrenal Pathway
1) Stressor acts on Hypothalamus in the brain. 2) The Hypothalamus activates the Pituitary gland. 3) The Pituitary gland releases ACTH. 4) This stimulates the adrenal cortex.
5) Cortisol is released into the bloodstream which suppresses the immune system and facilitates the conversion of fat and protein into energy.
1) Stressor acts on Hypothalamus in the brain.
2) The Hypothalamus activates the sympathetic branch of the ANS.
3) This stimulates the adrenal medulla which releases adrenaline and noradrenaline
4) Sweating, heart rate and blood pressure increases producing the fight or flight response.
Of course stress can cause health problems if not lasting over a significant period of time, this is chronic stress.
Pituitary Adrenal pathway deals with chronic stress and sympathomedullary deals with acute stress.
Acute Stress- Sudden and severe but short lived e.g. public speaking.
Chronic Stress*- Persists for a long time e.g. illness.
*I use the mnemonic chrOnic=Old to remember the difference but it is up to you.
Stress can affect illness directly by suppression of the immune system making us more susceptible to cold, flu, headaches and ulcers.
However Stress can also affect illness indirectly by affecting our lifestyle choices such as: Stress→ Smoking→ Lung Cancer/CVD'S
Research Focus: Kiecolt-Glaser
Aim: To see if stress affects the immune system by healing of a wound.
Procedure:13 female Carers (treating a family member with senile dementia) were matched by income and age but not marital status. Participants were volunteers. They were given a 3.5mm punch biopsy- a cut below their elbow and were given a ten item perceived stress scale.
Findings: The wounds of the carers took 9 nine days longer (24%) to heal than the control group and cytokines levels were lower in the carers. Carers reported more stress than the control group.
Conclusion: Stress does directly weaken the immune system which increases the time for a wound to heal.
Limitations: ✔ The findings have important implications for treating people with infections. It would suggest it is important that stress is reduced in patients in hospitals as much as possible in order to speed recovery. ✔ Control over extraneous variables. ✔ Volunteers which minimises ethical issues. ✖ Sample bias- All participants were females and carers so results can't be generalised for the population i.e. males and people of different occupations. ✘ Small sample
Research Focus: Cohen, Tyrell and Smith
Aim: To see whether the effect of stress on resistant to disease as an indicator of immune functioning.
Procedure: 394 healthy participants were asked to complete a questionnaire about stress levels. They were then split in to two groups and either administered a cold virus (experimental group) or saline…