Stress - The Immune System and Stress Flashcards
Explain Natural Immunity?
Cells are called macrophages or phagocytes - made up of cells from the bloodstream
They non specifically attack or ingest invading pathogens or viruses
Innacurate
What different sections is Immunity split into?
Natural Immunity
Specific Immunity which is split into Cellular And Humoral Immunity
Explain Specific Immunity?
Takes longer to recognise but very accurate
Based in cells such as lymphocytes
Destroys invading pathogens with a sophisticated system
Explain Cellular Immunity?
Includes killer/memory/helper T cells
Involves cells called T Lymphocytes that grow in the thymus gland
The T cells attack intracellular (within) pathogens like viruses
Explain Humoral Immunity?
Another type of lymphocytes called B cells that grow in bone marrow
The end product is the secretion of antibodies from B lymphocytes and attack extra cellular (outside) cells such as bacteria or paracites
Explain the Cohen et al experiment?
394 ppts completed questionnaires on the number of stressful events in their daily life in the past year
They rated their degree of stress and levels of negative emotions.
They were also exposed to a clinical common cold and 82% of ppts became infected - the people with higher stress levels developed the cold quicker.
Explain a critic of Cohen’s experiment?
The study is correlational meaning that they cannot distinguish cause and effect meaning that there is a high possibility of extraneous variables, they also did not manipulate the levels of stress.
Explain a strength of Cohen’s experiment?
It is supported by other research, Evans and Edginton found that negative events predicted the likelihood of getting a cold. Also Cohen’s findings have been replicated by others.
Explain Kiecolt-Glaser’s experiment?
Natural experiment using 75 medical students - blood samples were taken 1 month before the final exam and during the exam period - and the students had to answer a questionnaire about life events and loneliness.
They found from this that due to the T cell activity being significantly reduced during exam period that the stress causes a reduction in immune function - making them more vulnerable to illness.
Explain a critic of Kiecolt-Glaser’s experiment?
The findings are not generalizable, study only uses medical students = non representative, cannot represent everyone as all one age as well.
They should’ve used a more varied group of ppts to increase population validity.
Explain a strength of Kiecolt-Glaser’s experiment?
Their findings are supported by other research - such as the immune functions is reduced in LT carers of Alzheimer’s patients and women going through a divorce.
These results are representative of more of the population.
What did Sergerstrom and Miller want to find out?
Whether there was an effect of different stressors on measure of the immune system function.
Define the Acute time-limited stressors?
Lead to the up-regulation of natural immunity, measured for example by the number of natural killer cells.
This is logical as natural immunity is fast and would be activated immediately by stressors.
Define the brief naturalistic stressors?
That there is no overall effect in immune function despite Kiecolt-Glaser experiment, but there was evidence for a shift between cellular and humoral immunity.
Define chronic stressors?
These have the most consistent effects on the immune system, chronic stress etc. causes the down regulation of immune function across gender and age.
