stress

• Sympathomedullary pathway (SAM)

  Perceives a threat, hypothalamus altered, coordinates a response from autonomic nervous system (ANS)
• Sympathomedullary pathway (SAM)


  • Arouses the Sympathetic branch of the ANS
  • Sends signal to adrenal medulla to release noradrenaline
  • Circulates the body targeting organs like heart and muscles
• Threat passes

  Response dampened by parasympathetic branch of ANS
• Fight/Flight Response

  Changes caused by the released adrenaline and noradrenaline to get the body ready for fight or flight
• Fight/Flight Response

  • Oxygen carried to muscles to make them work harder
  • Blood vessels in salivary glands constricted, mammary glands and we sweat to cool us down
  • Prepares body for the stressor
• Fight/Flight response evolved as an adaptive strategy to deal with threats our ancestors may have faced
• Modern stress can trigger the fight/flight response when no action is taken, leading to a permanent state of arousal which can cause problems for the body
• High adrenaline levels


  Can have direct effects on the heart, leading to cardiovascular disorders like heart attack and stroke
• Sympathetic arousal

  Causes the heart to work faster, blood vessels and arteries can become blocked with plaque
• Individuals who experience release of adrenaline in response to stress may have thickened arteries, increased white blood cells, and increased risk of blood clots leading to heart attack
• CHRONC+CORTISOL

  The HPA Axis
• The HPA Axis


  1. Stressor encountered

  2. Initial response triggered

  3. Slower response (HPA System)
• Hypothalamus


  Produces corticotropin releasing hormone (CRH) into body
• Pituitary gland


  Releases adrenocorticotropic hormone (ACTH)
• Adrenal gland


  Stimulates release of cortisol
• Lacey et al (2000)

  • Prospective investigation of groups preparing for exam, compared to matched control group
  • Students showed elevated cortisol 1 hour before exam
• Cortisol

  • Steroid hormone, part of the glucocorticoid family
  • Usual functions in central nervous system - learning/memory, regulating glucose storage, immune system
• Cortisol released during stress

  Impairs memory
• Kuhlmann et al (2005)


  • Gave cortisol to group of women and asked to recall 30 words
  • Cortisol group showed significantly reduced recall, especially for negative words
• Effect of cortisol on memory has implications for performance under stress, explaining why students say their 'mind goes blank' when going into an exam
• Effects of cortisol on health

  • Immunosuppression - faced with a stressor, the immune system is seen as a non-essential function and shuts down to direct energy elsewhere
• Janice Kiecolt-Glaser et al (1984)


  • Measured natural killer (NK) cell activity in medical students 1 month before and during exams
  • NK cell activity was reduced during exams
• If the stressor continues, there is a risk of increased infections
• People suffering from Cushing's syndrome, which involves high cortisol levels, also show reduced NK cell activity
• Hardiness

  A personality trait that helps people deal with stress
• Hardiness

  • Consists of 8 elements
  • Involves a sense of control over one's life rather than external factors
  • Involves a sense of purpose and meaning in life
  • Involves curiosity about the world around them
  • Sees stressful events as opportunities for growth and development
  • Does not expect life to be easy and learns from failures
• Having hardy personality characteristics

  Leads to better coping strategies against stress, such as self-care and use of social support
• Having hardy personality characteristics

  Leads to lower physiological stress response and less likelihood of stress-related illness
• Research studies on hardiness

  • Kobasa compared two groups of male business executives, one group more hardy than the other
  • Maddi studied employees of a company experiencing a stressful period of redundancies, finding 1/3 demonstrated hardy personality
• Further research has shown that social support can benefit against the effects of stress, and hardiness has been most significant
• Individuals with higher levels of hardiness are better able to cope with stress as a result of life events
• Hardiness may be an important factor in resilience, allowing people to experience stressful events without long-term negative consequences
• Type A and Type B personalities differ in their response to stress
• Type A person

  Competitive and hostile
• Type B person

  Calmer and more able to express feelings
• Development of Type A/B theory

  1. 1950s Freidman + Roseman observed behaviour in a waiting room

  2. Noticed some seemed tenser and exhibited certain behaviours, while others seemed relaxed
• Type A personality

  Linked to stress-related responses
• Type A people are likely to experience a fight/flight response
• Type A people are likely to have more adrenaline released on a daily basis
• Type A personality

  Higher blood pressure, heart rate, and wear and tear on blood vessels