Stress

Question 1

Outline the sympathomedullary (SAM) pathway

Answer 1

The SAM pathway is activated in response to an acute stressor, immediately triggering the fight-or-flight response:
- Sympathetic nervous system: autonomic system triggers SNS to stimulate adrenal medulla
- Adrenal medulla releases adrenaline and noradrenaline
- Adrenaline + noradrenaline circulate and affect target organs (heart and muscles)

Question 2

Outline the hypothalamic pituitary-adrenal (HPA) axis

Answer 2

Activates alongside SAM pathway, but the response is slower since it is hormonal
- Hypothalamus releases corticotropin releasing factor (CRF)
- Pituitary gland is stimulated by CRF to produce adrenocorticotrophin hormone (ACTH)
- Adrenal cortex is stimulated by ACTH to release corticosteroids e.g. cortisol

Question 3

State the 3 stages of general adaptation syndrome

Answer 3

The stages aim to model the universal physiology of stress:

Stage 1 - Alarm
Stage 2 - Resistance
Stage 3 - Exhaustion

Question 4

Outline Selye’s alarm stage of GAS

Answer 4

• The stressor is identified
• Sympathetic nervous system is activated
• Fight or flight response is triggered

Electrical impulses makes this response fast

Question 5

Outline Selye’s resistance stage of GAS

Answer 5

• If stressor is not dealt with, endocrine system is triggered
• HPA axis is triggered to release cortisol in the blood
• Body’s resources gradually deplete but the body appears to be coping

This system is slower since it relies on hormones in the bloodstream to trigger each part of HPA

Question 6

Outline Selye’s exhaustion stage of GAS

Answer 6

• Body can no longer maintain normal functioning

Question 7

What are 2 evaluations of the physiology of stress?

Answer 7

1. Fight or flight is maladaptive, as it is suited for energetic behaviour
2. May be gender-biased - research from rats suggests oxytocin may inhibit fight-or-flight, and instead encourage tend and befriend

Question 8

What is an evaluation of Selye’s GAS?

Answer 8

1. Increased hormone activity of cortisol may better explain exhaustion than a ‘depletion’ of resources, since resources (such as neurotransmitter and hormones) do not become ‘depleted’

Question 9

What is the role of stress in illness?

Answer 9

If the stress response is chronic, it may lead to gradual wear and tear of the immune and cardiovascular system

Question 10

How does stress affect the cardiovascular system?

Answer 10

Stress activates the sympathetic NS which produces adrenaline and noradrenaline, and these hormones lead to:
- increased heart rate weakens heart
- vasoconstriction, which increases blood pressure
- atherosclerosis via high BP

Question 11

Outline Williams et al’s (2000) study on anger and heart disease

Answer 11

Aim: to see whether anger was linked to heart disease since anger also activates sympathetic NS
Procedure: 13,000 ppts (with no heart disease) filled out an anger scale with questions such as ‘are you hot headed?’
Findings: 6 years later the health of ppts was checked; 256 experienced heart attacks - those who scored highest on the test were 2.5x more likely than those who scored lowest to suffer a heart attack
Conclusion: SNS arousal is closely associated with cardiovascular disorder

Question 12

How does stress affect the immune system?

Answer 12

Ongoing stress activates the HPA axis which releases cortisol; cortisol reduces the body’s immune response which increases likelihood of becoming ill

Question 13

Outline Kiecolt-Glaser et al’s (1984) study on chronic stress and immune functioning

Answer 13

Aim: to investigate the effect of important exams on immune functioning
Procedure: 75 medical students had blood samples taken a month before (low stress) and the day of their exam period (high stress) - functioning was assessed by NK cell activity, and ppts completed a social readjustment rating scale (SRRS)
Findings: NK cell activity was significantly reduced in high stress sample, especially when life stressors and loneliness were high
Conclusion: ongoing stressors reduce immune system functioning

Question 14

What are some evaluations of the role of stress in illness?

Answer 14

1. Cardiovascular effects researched via self-report measures; reduces reliability as results are skewed away from what is accurate due to perception - tendency for negative views exaggerates effect
2. Individual differences need to be accounted for: age, gender, and hyperresponsiveness of sympathetic branch of ANS

Question 15

Define life changes as a source of stress

Answer 15

Life changes are events in a person’s life that require significant adjustments, therefore they cause stress due to the expended psychic energy to deal with change

Question 16

How are life changes measured?

Answer 16

Holmes and Rahe: The Social Readjustment Rating Scale (self-report)

Question 17

How does the SRRS work?

Answer 17

• consists of 43 life events: individ. selects the ones they experienced in a set time period
• LCU (life change units) are assigned to each life event; the higher the number, the higher the stress
• death of a spouse: 100LCUs, pregnancy: 40LCUs, divorce: 73LCUs

Question 18

Outline Cohen et al’s research on life changes

Answer 18

• gave ppts nasal drops with the common cold virus and assessed their life changes using the SRE (schedule of recent experiences; adapted ver of SRRS)
• also assessed ppts’ perceived stress scale
• ppts were quarantined to see if they developed cold
• ppts with higher LCUs were more likely to catch a cold, and there was no link between perceived stress and illness