Stress

• Bodies response to short term stressors - The Sympatho-medullary pathway

  1. Signal sent down the SNS of our autonomic nervous system

  2. Stimulates our adrenal medulla

  3. Signal sent via our central nervous system to the adrenal glands

  4. Adrenal medulla responds by releasing adrenaline and noradrenaline into our bloodstream

  5. Adrenaline and noradrenaline circulate throughout our bodies and affect the key target organs like the heart and muscles
• The Hypothalamic-pituitary adrenal system (HPA)

  1. Hypothalamus activated by a detected stressor

  2. Sends signal to stimulate the SNS

  3. Produces corticotropin releasing factor (CRF) into the bloodstream

  4. CRF stimulates the anterior lobe of the pituitary gland

  5. Pituitary gland releases ACTH into the bloodstream

  6. ACTH triggers the release of stress-related hormones known as corticosteroids like cortisol into the bloodstream
• Immunosuppression


  Reduced immune system performance due to corticosteroids redirecting energies to other parts of the body like the brain and muscles
• Cortisol


  • Plays an important role in the bodies stress response by providing the body with glucose, having an anti-inflammatory role, and weakening the immune system
  • Constricts blood vessels and increases blood pressure to enhance the delivery of oxygenated blood, which can lead to vessel damage and plaque build-up in the long term
• General Adaptation Syndrome (GAS)

  Model developed by Hans Selye (1956) arguing that the physiological effect of stressors was to leave humans and animals vulnerable to illness
• General Adaptation Syndrome (GAS)

  1. Stage 1 - Alarm Reaction

  2. Stage 2 - Resistance

  3. Stage 3 - Exhaustion
• Alarm Reaction stage


  • Similar to typical fight or flight response
  • A threat or stressor is recognised, and physiological responses are activated as a signal is sent to the hypothalamus
  • Stimulated by the hypothalamus the sympathetic nervous system activates and stimulates the adrenal medulla to secrete adrenaline and noradrenaline (stress hormones)
• Resistance stage


  • If the stressor continues, the fight or flight response in the SNS ceases but stress hormone output (adrena/noradrena) increases from another part of the adrenal gland, the adrenal cortex
  • The adrenal glands may become enlarged as a result
• Exhaustion stage


  • If the stressor continues for a long time, the body's resources such as energy are reduced
  • The immune system may be damaged
  • Stress related diseases such as high blood pressure and other cardiovascular illness or even ulcers are likely to occur
• The immune system may be compromised
• Personality


  Could perhaps explain individual differences in response to stress
• Type A personality


  • High levels of time urgency
  • High levels of competitiveness
  • High levels of hostility
• Type B personality


  • More relaxed and 'laid back'
  • Tolerant and reflective
  • Non-competitive in their manner
  • Have the same level of ambition as Type A but more steady and self-confident
  • Capable of relaxing and doing nothing
• Type C personality


  • Strongly suppress their emotions, particularly the negative ones
  • Passive, unassertive and 'people pleasers' that may manifest as pathological niceness
  • Cope with stress in a way that ignores their own needs, including physical needs that can result in negative consequences
• Type A and B personality


  • Type A personality associated with higher stress levels and higher risk towards cardiovascular diseases
  • Type B personality associated with lower stress levels and lower risk towards cardiovascular diseases
• Friedman and Rosenman conducted an eight-and-a-half-year longitudinal study into 3000 healthy men aged between 39 and 59


  1959, 1974
• Friedman and Rosenman's study

  1. Examined participants for signs of CHD and excluded those already showing signs

  2. Assessed personalities through interview with 25 questions about how they responded to everyday pressures

  3. Conducted interview in a provocative manner to elicit Type A behaviour
• 70% of those with CHD, high cholesterol and high adrenaline were Type A personality
• 12% of individuals classed with Type A had a heart attack compared to only 6% of those classed with Type B
• Type C personality traits


  Have been linked to some cancers, due to stressors activating the autonomic nervous system, which is related to CHD
• As most chronic stressors affect healthy immune system functioning, this in turn increases the risk of cancer
• Women who had cancerous breast lumps experienced far less anger than those women whose lumps were found to be non cancerous, supporting the theory of a link between the suppression of anger in line with Type C personality traits
• The HPA axis is the hypothalamic-pituitary-adrenocortical axis
• Friedman and Rosenman's study


  • Consisted only of men, therefore difficult to generalise the results to women who have different ways of dealing with stress and might be less vulnerable
  • Shows a gender bias in psychology
• Greer and Morris (1975)

  • Age is a more reliable predictor of the development of cancer compared to the incidence of individuals with Type C personalities
  • Found a strong positive correlation between Type C personalities and increasing cancer incidence rates, but only up to age 50
  • After which there have been inconsistent findings and causal conclusions that have been incorrectly made due to a lack of replication
  • Reduces the validity of personality types as an explanation for stress
• Hardiness


  "a stronger commitment to self, an attitude of vigorousness toward the environment, a sense of meaningfulness and an internal LOC"
• Kobasa's theory of hardiness


  • Developed to explain individual differences in the reaction to stress that had been overlooked in the research by Holmes and Rahe amongst others, who failed to account for the fact that not everyone exposed to a high level of stress became ill
• Personality traits of hardy individuals

  • Commitment to self - having a clear sense of ones own values, goals and capabilities and a belief in their importance and purpose
  • Challenge - viewing change as expected and normal and receiving stressors as challenges to be mastered, seeing both as opportunities to learn rather than as a source of stress
  • Control - Having an internal LOC and thus feeling that one has power over decisions and situations, but also how challenges are met
• Kobasa (1979) studied the effects of personality types on a group of male business executives
• Kobasa's research was done on wealthy managers, so results are not generalisable to other sections of society
• Subsequent research on soldiers, firefighters and students has supported Kobasa's findings
• Benzodiazepines (BZs)


  The most commonly used drugs to treat anxiety and stress, they slow down the activity of the CNS and are commonly known as diazepam
• How BZs reduce anxiety

  1. They enhance the actions of GABA, the body's natural anxiety relief

  2. GABA reacts with GABA-A receptors on the outside of post synaptic neurons, opening a channel which increases the flow of chloride ions into the post-neuron

  3. This makes it harder for the post-neuron to be stimulated by other neurotransmitters, slowing down its activity and resulting in a person feeling more relaxed and less anxious

  4. BZs also dampen the excitatory effects of serotonin, further slowing down the activity of the nervous system and adding to the feelings of relaxation
• Beta Blockers - Propranolol and Alprenolol


  Also known as beta adrenergic blockers, they act on the sympathetic nervous system by blocking areas which are normally activated by the hormones adrenaline and noradrenaline released in response to stressors
• How beta blockers work

  1. They block the transmission of nerve impulses by sitting on beta adrenergic receptors that would normally be hormone-activated

  2. Adrenaline and noradrenaline would normally combine with beta-adrenergic receptors located throughout the cardiovascular system, principally receptors located in the heart and blood vessels, resulting in increased heart rate and blood pressure

  3. Beta blockers effectively block the beta-adrenergic receptors from being stimulated by adrenaline and noradrenaline, which slows down the heart, reduces blood pressure and causes the heart to pump less intensely
• Beta blockers


  • Very helpful for people with high blood pressure, although they can interact with others drugs as those taken with asthma
  • Don't have severe side effects as the drugs mainly act on the body, not the brain