The Psychophysiology of Stress - Essay Example

PAGE Effects of stress 2. Psychological effect of stress. 3. Physiological effect of stress 4. Fight and flight response 5. Evolutionof physiological system during Pleistocene 6. EEA or environment of evolutionary adapted ness. EFFECTS OF STRESS Effects of stress:- Stress results in disorders which ultimately leads in disturbing psychological and physiological reactions that occur when environment event threatens important motives and taxes one's ability to cope. In a positive way stress is essential for life's as it adds dullness and exciting .It adds challenge and opportunity to life. The challenges caused by stress helps to develop new skills, but the problem occur when the level of stress increases. Too much of stress may make life miserable which will eventually disturb the psychological and physiological responses of living. Psychological effect:- The molecular mechanism due to which the nerve cells (neurons) involved in memory store information are only partly characterized but in appears that, in response to new 'signals', neurons change chemical and structural properties to reach a new homeostatic 'set point' which contains information'. We generally think of memory as the storage and recall of cognitive information --- names, faces, phone numbers and arithmetic yet the same neurophysiologic mechanisms involved in storing and recalling cognitive information are involved in making complex memories of a psycho physiological state this involves non-cognitive domains. The human brain can store and recall all, or a portion, of the emotional (e.g., intense anxiety) and physiological concomitants (e.g., increased heart rate) of certain life events. In this review psycho physiological aspects of exposure to traumatic and stressful life events such as rape, sexual abuse, combat or physical harm will be considered. Understanding the mechanisms by which psycho physiological 'memories' of fear and arousal result from traumatic stress has significant public health implications, each year millions of children and adults are victimized by physical, sexual or severe Psychological abuse. The psycho physiological sequel of these traumatic events appear to make an individual vulnerable to the development of various psychiatric disorders and, further, these 'state' memories appear to play an major role in the etiology of post- Traumatic stress disorders (PTSD). Physiological effect of stress:- When under pressure, some people are more likely to drink heavily or smoke, as a way of getting immediate chemical relief from stress. Others may have so much work to do that they do not exercise or eat properly. They may cut down on sleep, or may worry so much that they sleep badly. They may get so carried away with work and meeting daily pressures that they do not take time to see the doctor or dentist when they need to. All of these are likely to harm health. The direct physiological effects of excessive stress are more complex. In some areas they are well understood, while in other areas, they are still subject to debate and further research. The link between stress and heart disease is well established. If stress is intense, and stress hormones are not 'used up' by physical activity, our raised heart rate and high blood pressure put tension on arteries and cause damage to them. As the body heals this damage, artery walls scar and thicken, which can reduce the supply of blood and oxygen to the heart. This is where a fight-or-flight response can become lethal: Stress hormones accelerate the heart to increase the blood supply to muscles; however, blood vessels in the heart may have become so narrow that not enough blood reaches the heart to meet these demands. This can cause a heart attack. Stress is also associated with mental health problems and, in particular, anxiety, and depression. Here the relationship is fairly clear: the negative thinking that is associated with stress also contributes to these. The direct effects of stress in other areas of health is still under debate. In some areas (for example in the formation of stomach ulcers) diseases traditionally associated with stress are now attributed to other causes. Regular exercise can reduce your physiological reaction to stress. It also strengthens your heart and increases the blood supply to it, directly affecting your vulnerability to heart disease. Stress has both positive and negative impacts on lives. Acute stress have positive reaction on individual i.e., release of steroid hormones, release of catecholamine, lungs take more oxygen due to rapid breathing, the flow of blood increases by 300-400%, discharge of white and red blood cells through spleen. The negative effect of stress are when there is excess of release of stress hormones they produces hyperactivity in Hypothalamus-pituitary-adrenal axis and disrupts normal levels of serotonin. Stress activates sympathetic nervous system which is the automatic part of nervous system that affects many organs, including the heart. Stress may initiate the body to release to Fats. Stress results in susceptibility to infections. chronic stress blunt the immune response and increase the risk for infections and even impairs a persons response to Immunization. stress may also lead to gastrointestinal disorders as brain and intestine are closely related to same hormones and nervous system. stress develops insulin- resistance (the body is unable to produce glucose, which ultimately leads to diabetes). Fight and flight response due to stress. In 1914 Walter B. Cannon first coined the phrase "fight or flight" to describe the body's appropriate response to stressful stimuli. When an individual is exposed to real or perceived danger, a series of complex, interactive neurophysiological reactions occur in the brain, the autonomic nervous system, the hypothalamic-pituitary adrenocortical (HPA) axis and the immune system. These responses evolved to provide the critical total body mobilization required the individual to survive a life-threatening danger. In the initial phases, first labeled 'the alarm reaction' and the 'stage of resistance' by Hans Selye in 1936, portions of the brain involved in arousal, attention and concentration functions become activated resulting in hyper vigilance to the threat and decrease in attention to less pressing environmental stimuli -- a soldier in the midst of a Firefight, for example, may not know he has been wounded until the end of the fight. If an affective state is experienced during the alarm reaction (again, the hyper vigilance may be so intense during the acute phase of a traumatic event that the individual does not attend to his or her own internal state), it is anxiety. The degree of anxiety varies with the degree of threat, ranging from 'jitters' to outright panic and terror. In addition to changes in brain functioning, other organ systems are involved in the alarm reaction. The sympathetic division of the autonomic nervous system (SNS), which originates in the brain and distributes throughout the rest of the body, plays a major role in effecting and orchestrating the brain's mobilization of the rest of the body. The activation of the SNS increases blood pressure and pulse, dilates the pupils, increases respiratory rate moreover, increases the blood supply to the muscles. The HPA axis is activated releasing a variety of stress related hormones including ACTH and beta-endorphin, which decreases, pain perception. Neural and hormonal signals (e.g., ACTH) activate the adrenal glands, which release important stress related Hormones including epinephrine (or adrenaline) and cortisol. These hormones enter the bloodstream rapidly, acting in all organ systems to prepare the body to 'fight' or 'flee'. These neurophysiological activation responses are rapid and reversible. The cost of this adaptive hyper-arousal mechanism is great; the alarm reaction consumes energy and depletes stores of available neurotransmitter and hormone. With sufficient time between threatening events, however, the body can return to a previous homeostasis or equilibrium by replenishing the stores of neurotransmitter, hormone, glucose and other important chemicals. When the stressful event is of a sufficient duration, intensity, or frequency, however, the body does not have the capability to sustain this high state of arousal the stress-responding apparatus becomes fatigued. Evolution of physiological systems during Pleistocene:- The climatic conditions of the Pleistocene period were completely different when compared to present age. More than of the earths land was covered by ice and the Environmental conditions were completely different. Adrenaline stimulates the adrenal glands present in the body, which are responsible for producing a broad spectrum of Hormones, which cause stress response. During the Pleistocene age adrenaline was a unique and essential for survival as the climatic conditions of the Pleistocene age were different from the present environmental conditions. Many therapies have developed to overcome stress in the present conditions. Stress can be defined as a state we experience when there is a mismatch between perceived demands and our perceived ability to cope. Stress can also be defined as an adaptive response by a body to change in the environment. stress response evolved to enable humans to deal with life-threatening dangers or stressors such as being Confronted with a wild animal or perhaps a hostile human. Situations like this required action - the activation of stress response to wither stay and fight or to run away. Today we hopefully won't have to face the same dangers as our ancestors but the stress response to demanding situations we face is still with us and our mind and body still prepare for fight or flight when confronted with this equivalent of the wild animal. The fight or flight response is a very old and very basic response and has been with us for a very long time. It was originally a response to danger that would prepare our ancestors to fight the wild beast or the enemy who might suddenly threaten or confront them, or to take flight and literally run away from the danger. This response is triggered when we send a message of alarm to a part of the brain called the hypothalamus. This area of the brain will then send a signal to the glands to release adrenaline, cortisol and Endorphin into the blood stream. Increased levels of adrenaline increase heart rate and blood flow, which in turn brings extra oxygen and glucose to the muscles. Cortisol causes an increase in amino acids and sugars in the blood. Amino-acids are crucial for the repair and recovery of damaged tissues which may occur under stress and the blood sugar adds to the availability of glucose (fuel) for the body. The release of endorphin, which is a morphine like substance only more powerful, provides the body's natural Tranquilizing system. Pain is blocked and a feeling of euphoria may be experienced, both helping to get the body through the situation it finds itself in due to stress. We still have this response as it remains necessary to prepare and protect us in times of alarm, such as being involved in an emergency situation or being confronted with any form of potentially life Threatening danger. Once the initial stages of this fight or flight response are over, a person will have a psychological reaction to the stressor which will be based upon many variables including, personality type, conditioning, age, physical and mental ability, and knowledge relevant to the situation to be dealt with. The release of endorphin, which is a morphine like substance only more powerful, provides the body's natural tranquilizing system. Pain is blocked and a feeling of euphoria may be experienced, both helping to get the body through the situation it finds itself in due to stress. We still have this response as it remains necessary to prepare and protect us in times of alarm, such as being involved in an emergency situation or being confronted with any form of potentially life threatening danger. Once the initial stages of this fight or flight response are over, a person will have a psychological reaction to the stressor which will be based upon many variables including, personality type, conditioning, age, physical and mental ability, and knowledge relevant to the situation to be dealt with. EEA or environment of evolutionary adapted ness:- The EEA concept is extremely important for understanding the functional properties of organisms, including the functional organization of the human brain. As outlined in the previous section, the functional properties of organisms arise by the process of evolution by natural selection. This means that the functions that organisms have are precisely those that solved long-standing, recurrent reproductive problems. Reproductive problems are all the various things organisms had to do to survive and reproduce in a particular environment over evolutionary time find food, find mates, avoid predators, combat pathogens, etc. The human EEA is been broadly equated with Pleistocene. Evolutionary psychology proposes that a majority of human psychological mechanism is adapted to reproductive problems. The EEA for any specific organism is the set of reproductive problems faced by members of that species over evolutionary time. The EEA concept therefore provides a much needed tool for determining, a priori, what kinds of functions, or mechanisms, the human brain is likely to have: the human brain solves the reproductive problems posed by past environments; it allows us to do all the things we needed to do to survive and reproduce in ancestral environments--find food, find mates, detect, and avoid predators and other dangerous animals, etc. We can understand the functional organization of human bodies and brains precisely to the extent that we can understand the human EEA. Reference:- Sadock BJ, (2003) psychological factors affecting the medical conditions. JD Bremner, DS Charney, (1995) Journal of traumatic stress. P Jin, (1992) Journal of psychosomatic research. BB Arnetz, (1996) Journal of occupational and environmental stress. M Maes, (1998) behavioral stress. Cacioppo, J. T., Tassinary, L. G., & Berntson, G. G. (2000). Handbook of Psychophysiology, second edition, New York. Cambridge university. 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