Biological Explanation - Cortisol And Chronic Stess Flashcards
Explain the HPA pathway
When a stressor is first encountered, the SAM response is triggered, at the same time a slower response is triggered, the hypothalumus procudes CRH, which causes the pituitary gland to release ACTH, which triggers the adrenal cortex to release cortisol
Why is the HPA pathway triggered?
To allows the body to deal with long-term stressors
What is cortisol?
Cortisol is a steroid hormone, its usal function is to play a role in the CNS, where it is involved in learning and in memory and regulates glucose storage and the immune system
Explain what cortisol does in the HPA pathway
It lowers sensitivity to pain and releases glucose for energy over a sustained period of time, making us more able to deal with a long-term stressor, however it can effect memory and health
What are the effects of cortisol on memory? (Description)
It may impair memory - research adminstered cortisol to a group of women and gave them a list of 30 words to remember, those given cortisol showed significantly reduced ability to recall words - e.g may explain why ‘mind goes blank’ in exams
What are the effects of cortisol on health? (Description)
Immunosuppression - when faced with a stressor, the immune system is seen as a non-essential response, so is shut down to divert the energy elsewhere, this is done by reducing the inflammation caused by the immune system
However, if the stressor continues, so does the immunosupression, which significantly increases an indviduals risk of becoming ill
What research supports the idea that cortisol causes immunosuppression? (Description)
Research measured the natural killer (NK) cell activity of 75 medical students and found that the activity was significantlly reduced in the blood sample taken during the exam period itself
The students also completed a SSRS and found those with the highest score on the SSRS had the lowest NK cell activity
What are the 4 evaluation points for cortisol and chronic stress?
Low levels of cortisol causes health problems
Issues in research studies
Stress is not always bad for immune system
Stress doesn’t always raise cortisol
Explain the evaulation point of low levels of cortisol causes health problems
Its well know that a sudden drop in cortisol levels can also cause illness (e.g getting ill after exams)
Research has linked PTSD and Chronic Fatigue Syndrome to low levels of cortisol
Explain the evaulation point of issues in research studies
Establishing the cause and effect relationship between cortisol release and illness is difficult, because people are far more likely to change eating habbits, may not sleep as well etc
Research suggests gender differences - when put in a stressful situation, boys showed greater cortisol release
Explain the evaluation point of stress is not always bad for the immune system
Its suggested that in some cases, stress actually enhances the activity of the immune system
Research looked into the activity of an antibody - sigA, the researcher arranged for students to give talks to other students (immediate stress) showed increased activity of sigA, but reduced over exam seasons
So either up or down
Explain the evaluation point of stress does not always raise cortisol levels
A review shows inconsistency in research regarding the bodies response to stress, a review of studies showed that there was a a varation during exam stress from a 58% decline to a 95% increase in cortisol levels - lack of longitudinal element to asses long-term levels?
Explain the path of HPA (flow chart style)
Stressor –> hypothalamus releases CRH –> pituitary gland releases ACTH —> adrenal cortex releases cortisol
