stress is a biological and psychological response experienced on encountering a threat that we feel we do not have the resources to deal with.
A stressor is the stimulus (or threat) that causes stress, e.g. exam, divorce, death of loved one, moving house, loss of job.
Sudden and severe stress generally produces:
· Increase in heart rate
· Increase in breathing (lungs dilate)
· Decrease in digestive activity (don’t feel hungry)
· Liver released glucose for energy
Stress is an intimate and personal affair, and for this reason we can only infer its existence in other people from their verbal accounts, their general appearance and demeanour, and their behaviour. As we have seen, stress is generally described in terms of the emotions which include the concepts of fear, sorrow, guilt, anger, anxiety or depression. Psychologists generally propose two kinds of emotional experiences: positive emotions and negative emotions, of which one of the negative emotions is stress. Lazarus (1976) actually regards the totality of negative emotions as ‘stress emotions’, but this ignores the contributions made by other factors.
Stress is the body's biological response to an actual or perceived stressor. In our evolutionary past, stress responses would have been essential to survival as they enable the body to respond quickly to danger. Today there is less danger in our environment, but the stress response is still essential to survival, however it sometimes responds to pressures and events it was not designed for and can lead to psychological and physical illness.
There are two main stress responses in the human body. The acute stress response (also known as the SAM or sympathy adreno medullary pathway) responds very quickly to immediate danger and readies the body for the classic fight or flight response. The chronic stress response (also know as the HPA or hypothalamo pituitary adrenal pathway) responds to long-term constant stressors by keeping the body alert, however the chronic response can also have many harmful effects on the body such as reducing immune system functioning.
Stressful events that persist for an extended period of time are perceived by the hypothalamus. The hypothalamus (located in the brain) releases CRF (corticotropin releasing factor) which travels through the blood to the pituitary gland (also in the brain). The pituitary gland releases ACTH (adrenocorticotropic hormone) which travel through the blood stream to the adrenal cortex (part of the adrenal gland situated at the top of each kidney) which releases corticosteroids (including cortisol). Cortisol has a wide range of effects on the body including increased blood pressure, sweating, vigilance, improved emotional memory, increased production of glucose from glycogen in the liver, and weakens the immune system.
Stressors have a major influence upon mood, our sense of well-being, behavior, and health. Acute stress responses in young, healthy individuals may be adaptive and...