Body's Response to Stress
- Sympathomedullary Pathway - Deals with acute stress, preparing the body for figh or flight.
Stressor > Hypothalamus > Brainstem > ANS > Adrenal medula > Release of adrenaline/noradrenaline
- Petuitory Adrenal System - Deals with chronic stress, taking 20 mins for the process to complete.
Stressor > Hypothalamus > Pituitary gland > ACTH (via blood stream) > Adrenal cortex > Release of hormones (corticosteriods)
- ANS - Consists of the sympathetic and the parasympathetic branch. The sympathetic branch increases heart rate, inhibits saliva, releases glucose etc. while the parasympathetic branch does the opposite bringing the body back to homeostasis.
There may be individual differences. Taylor found that men responded to stress with fight of flight while women responded with tend and befriend. Oxytocin is secreted by both men and women in response to stress but in men the effect is reduced, in women it's increased (due to other hormones). As a result, men are more vulnerable to the negative effects of stress.
There are consequences to the stress response. Increased bp can damage the lining of blood vessels eventually leading to heart disease. Similarly, too much cortisol can supress the immune response. Suggesting that you are vulnerable to illness e.g. infection.
Stress and the Immune System
- Kiecolt Glaser (relationship stress) - Tested the impact of interpersonal conflict on wound healing, blisters on the arms of married couples took longer to heal after a conflicting discussion. (chronic)
- Marucha (exam stress) - Looked at whether exam related immune changes have effect on the rate at which wounds heal. Inflicted a punch biopsy in the mauths of students over the summer and 3 days before the exam. Wounds inflicted days before took 40% longer to heal. (acute)
- Kieclot Glaser (exam stress) - Conducted a natural experiment on 75 medical students to see if the stress of important exams had an effect on the functioning of the immune system. Took blood samples a month before the exam (low stress) and during (high stress). NK cell activity reduced during high stress showing that exams reduce immune system functioning, you become vulnerable to illness. (acute)
There are reasons why a relationshipbetween stress and illness is hard to establish. Health is afffected by many different factors including genetic material and lifestyle as suggested by Lozarus.
Stress can enhance the immune system. Evens looked at an antigen called sigA which protects against infection. Students were asked to present a paper to the class and it was found that is increased the levels od sigA.
Researchhas shown differences between age and gender and stress and the immune system. Women show more immunological changes in reaction to marital conflict. As people age stress has a greater effect on the immune system as it becomes harder to regulate.
Stress Related Illness
- Williams (cardiovascular) - Study to see if anger was linked to heart disease. 15000 p's given a 10 question anger scale (none had heart disease), 6 years later 256 p's had experienced a heart attack. Scoring high made…