PassingPsych

Hormones are special chemical messengers in the body that are created in the endocrine system. This system has a series of glands that secrete different hormones into the blood which are then absorbed by different cells and change our behaviour. These messengers control most major bodily functions, from simple basic needs like sleep to complex systems like reproduction, and even emotion and mood. An example of a hormone is cortisol, also known as the stress hormone because it assists the body when responding to stress. Cortisol is released from the adrenal glands. This hormone has several functions, including releasing stored glucose from the liver (for energy) and controlling swelling after injury. However, chronic elevations in cortisol levels can result in cortisol suppressing the immune system. In this essay, I will give a detailed account including the reason and/or causes for the effects of hormones on behaviour using the supporting study of Kiecolt-Glaser et al.

Kiecolt-Glaser et al aimed to investigate the effects of a naturally occurring stressor on components of the immune response, in particular, whether the stress of important examinations affects the functioning of the immune system. (  assesses the effects of psychosocial modifiers (the external environment impacts psychological states) on immunocompetence in medical students). To investigate they used a natural experiment consisting of 75 1st year medical students. Blood was drawn twice from the students  (49 male and 26 female), all of whom were volunteers, with a baseline sample taken one month before their final examinations ( relatively low stress), and a stress sample drawn on the 1st day of the final examinations (high stress). The psychological response to stress would be the adrenal cortex to release cortisol into the bloodstream to increase blood sugar and metabolise fats, proteins and carbohydrates to give us the physical capacity to fight off the stress-inducing factor. Researchers wanted to look at the immune system, this was assessed by measuring T-cell activity in the blood samples. The students were also given questionnaires to assess psychological variables such as life events and loneliness including the Holmes-Rahe Social Readjustment Rating Scale and the UCLA Loneliness Scale ( the results of these were combined). This is because there are theories that suggest all 3 are associated with increased levels of stress. Results showed natural killer (NK) cell activity declined significantly from the 1st sample to the second sample ( meaning there were fewer T cells on the 1st day of their final examination). High scorers in stressful life events and loneliness had significantly lower levels of NK activity, as well as those who were experiencing other stressful life events and psychiatric symptoms such as depression or anxiety. They concluded that the stress from examination reduces the effectiveness of the immune system.

Kiecolt-Glaser demonstrated the role of cortisol on decreased immune-competence, For example, the medical students had a decreased number of white blood cells from the 2nd bn wood sample. This is important because as assessed by the questionnaire the stress of participants increased between samples, stimulating a higher release of cortisol from the adrenal gland into the bloodstream, causing overproduction of glucose, resulting in inflammation of white blood cells, stopping them from working. Therefore hormones have a role in behaviour.