The body's response to stress
The sympathomedullary pathway (SAM)
- Description: Response to short-term, emergency situations, fight or flight. Firstly, sympathetic nervous system is aroused (end of relaxed 'rest and digest' state). Secondly, the adrenal medulla is activated. Thirdly, adrenaline is produced, increasing heart rate and sugar production to deal with emergency situations.
- Evaluation: Strength: It identifies problems related to repeated SNS activity. Strength: explanation is it shows why individuals with an unreactive SNS are in danger. Limitation: fight/flight response is that it is not always adaptive.
The pituitary-adrenal system
- Description: The long-term response is triggered at the same time as the short-term SAM response. Firstly, the hypothalamus produces coritotropin releasing factor (CRF) which stimulates the pituitary gland. Secondly, the pituitary releases adrenocorticotropic hormone (ACTH). Thirdly, the adrenal cortex is activated to produce cortisol. The whole process takes about 20 minutes.
- Evaluation: Limitation: the process is too much production of cortisol can have negative effects. Strength: the pituitary-adrenal response is important for survial. Limitation: biological explanations is that the system can be controlled by congnitive factors.
Stress-related illness and the immune system
Kiecolt-Glaser et al. (1984) Exam-related stress.
- Aims & Procedure: Natual experiment with 75 students, dependent variable is immune system functioning assessed by measuring NK cell activity. IV was before or during period of stress (exams). Additional IVs were low/high stress as measured by SRRS and low/high loneliness.
- Findings & conclusions: NK cell activity was lower during exams. NK cell activity was lower for those with high SRRS score (high stress group). NK cell activity was lower for those with high loneliness score.
- Evaluation: limitation: natural experiment and therefore a casual conclusion not possible. Limitation: student participants were vounteers.
Kiecolt-Glaser et al. (1995) Wound healing.
- Aims & procedure: natural experiment with 26 women, dependent variable is immune system functioning assessed by measuring wound healing and cytokine levels. IV waas high stress (caring for elderly relative) or low stress (Control group). Perceived stress scale used to confirm stress levels.
- Findings & conclusions: wound healing was slower in the stressed group (carers). Cytokine levels were lower in the stressed group. Carers had higher perceived stress scores.
- Evaluation: Strength: real-world applications. Strength: supported by Marucha et al. (1998)
Holmes and Rahe (1967) The SRRS
- Aims & Procedure: List of 43 life events identified from 5000 patient records. 400 participants scored the life events for amount of readjustment required, with a baseline of 500 for marriage. Average calculated across all participants producing a LCU score for each event.
- Findings & conclusions: LCUs calculated, e.g divorce is 73 and jail term is 63. Positive events also have a psychological cost. The LCU scores are added up to provide an overall score. People with scores over 300 are more likely to become ill.
- Eval: strength: SRRS has had wisespread application. Limitation: SRRS overlooks smaller, everyday events and people may not have experienced any life events.
Rahe et al. (1970) Navy personnel.
- Aims & procedure: Men on board three US navy cruisers, total of about…