Stress and Illness - Stress - Lecture Slides, Slides of Psychology

Download Stress and Illness - Stress - Lecture Slides and more Slides Psychology in PDF only on Docsity! Stress and Illness - 1 BATs A01 – Outline how the Immune System works (D) A01/2 – Explain how stress may affect the Immune System (C) Stress response activity - place your card in the correct place on the body. Be prepared to talk about how your part of the response plays its part. Docsity.com Stress and Illness Stress Direct biological effects e.g. physical strain, hormonal changes Maladaptive coping behaviour e.g. smoking, drinking alcohol Emotionally mediated effects on diet and activity level Increased Risk of Disease Docsity.com The Immune System Cells of the Immune System Leucocytes (white blood cells) made in the bone marrow – B-cells Some stored in thymus gland, spleen or lymph nodes – T-cells Microphages (phagocytes) Pick up and ingest (eat) foreign bodies. They also present antigens to B-cells and T-cells for elimination T -L ym ph oc yt e Ph ag oc yt e Docsity.com Microphages (Phagocytes) actually ingest (eat) the microbes and then break them down once they are inside the cell. The microbe is destroyed by powerful digestive enzymes, which are released within the cytoplasm of the white blood cell. microbewhite blood cell Microphage cell surrounds the microbe. 1. Ingesting Microbes (phagocytes) Methods of attacking microbes Docsity.com Digestive enzymes attack the ingested microbe and begin to break it down. The microbe is destroyed. The chemicals that are released from the digested microbe are used in other parts of the cell. Methods of attacking microbes Docsity.com Methods of attacking microbes – The antibody will only work if it is connected to this specially shaped site. This design means that the antibody does not harm normal body cells because they do not carry the attachment site. These are the areas where the antibody will attach. microbe Docsity.com The antibody attaches to the specific site on the microbe, which leads to its destruction. microbe is destroyed attachment site antibody microbe Th2 Immunity B-cell - Lymphocyte (releases antibodies) Docsity.com Th1 Immunity T-cells are responsible for a more aggressive form of immunity. Known as Natural Killer (NK) cells, they detect cells in the body that are host to viruses. They then bump up against them, killing them. They protect against cancer cells as well as viruses Docsity.com Cytokines Stress can influence the balance between the 2 branches so that one is inhibited more than the other. Chronic stress – repeated HPA activation, production of cortisol – is associated with a shift away from Th1 immunity towards Th2 to ward off cancer. Thus cortisol may be responsible for SUPPRESSING the immune system. Docsity.com Stress & Immune Function Stress may adversely affect immune functioning through:  Diversion of energy resources away from maintaining immunity  Impact of stress hormones like cortisol on immune processes  Maladaptive coping behaviours Evidence that all three play a part Docsity.com Research into the link between Stress and Illness BATs A01/2 -Outline (E) and evaluate (B) research into the relationship between stress and illness A03 – Use data to see if there is a correlation between stress and illness (B+) Docsity.com Stress & Immune Function Onset Moderately prolonged Chronic Duration of Stressor Im m un e Fu nc tio ni ng 10 0% Merson (2001) Docsity.com Aim –To demonstrate the effect of stress on the immune system by looking at how quickly wounds heal. To get round the ethical issue of creating stress, participants were chosen because they were already experiencing high levels of chronic stress naturally – women caring for relatives with senile dementia. Procedures –Matched participants design. Recruited using newspaper ads – volunteer sample. 13 women carers aged 47-81 placed in the experimental group. 13 non- carers matched for age and income, not marital status (control group). Participants given a wound (punch biopsy). Wounds dressed and treated in the same way by a nurse. Assessed levels of cytokines (regulate body’s immune response) Participants given a 10 item perceived stress scale, to check how Star Study – Kiecolt-Glaser et al 1995 Docsity.com Findings – 1. Complete wound healing took significantly longer in carers than control group. Average 9 days (24%) longer. 2. Cytokine levels lower in carers than control group 3. On perceived stress scale, carers did actually indicate that they were feeling more stressed Conclusion –Supports the view that chronic stress depresses the immune system – because wound healing was slower in chronic stress patients. Lower levels of cytokines supports the view that stress lowers immune response directly Star Study – Kiecolt-Glaser et al 1995 Docsity.com A meta-analysis Segerstrom and Miller 2004 293 studies conducted over the past 30 years found … Short-term, acute stressors can boost the immune system, getting it ready to fight infections Long-term, chronic stressors led to suppression of the immune system – the most chronic causing the greatest and most widespread suppression The longer the stress, the more the immune system shifted from the body potentially being able to adapt to potentially detrimental changes Docsity.com Individual Differences Research has shown consistent gender and age differences in the stress/immune system relationship. Women show more adverse hormonal and immunological changes ion the way they react to marital conflict (Kiecolt-Glaser et al 2005) As people age, stress has a bigger effect on the immune system, making it harder for the body to regulate itself (Segerstrom and Miller 2004) Docsity.com Stress & Immune Function Evidence supports a weak link between stress and immune functioning The relationship is mediated by:  Personality & coping style  Social support  Lifestyle Compared to impact of e.g. age, genes, nutrition, stress is relatively unimportant Docsity.com