A related discipline behavioral medicine is an interdisciplinary fi eld that focuses on developing and integrating behavioral and biomedical knowledge to promote health and reduce illness Th e concerns of health psychology and behavioral medicine overlap Health psychology primarily focuses on behavioral social and cognitive infl uences Brannon Feist 2010 Norris others 2009 whereas behavioral medicine centers on behavioral social and biomedical factors Health psychology emphasizes psychology s role in establishing and maintaining health and preventing and treating illness Th is subfi eld of psychology refl ects the belief that lifestyle choices behaviors and psychological characteristics can play important roles in health The biopsychosocial model abbreviated BPS is a general model or approach positing that biological psychological which entails thoughts emotions and behaviors and social factors all play a significant role in human functioning in the context of disease or illness Indeed health is best understood in terms of a combination of biological psychological and social factors rather than purely in biological terms This is in contrast to the traditional reductionist biomedical model of medicine that suggests every disease process can be explained in terms of an underlying deviation from normal function such as a pathogen genetic or developmental abnormality or injury General adaptation syndrome GAS is Selye s term for the common eff ects on the body when stressful demands are placed on it Figure 17 2 Th e GAS consists of three stages alarm resistance and exhaustion Selye s model is especially useful in helping us understand the link between stress and health Th e body s fi rst reaction to a stressor in the alarm stage is a temporary state of shock during which resistance to illness and stress falls below normal limits In trying to cope with the initial eff ects of stress the body quickly releases hormones that in a short time adversely aff ect the functioning of the immune system our body s network of natural defenses During this time the individual is prone to infections from illness and injury In the resistance stage of Selye s general adaptation syndrome a number of glands throughout the body manufacture diff erent hormones that protect the individual in many ways Endocrine and sympathetic nervous system activity are not as high as in the alarm stage although they still are elevated During the resistance stage the body s immune system can fi ght off infection with remarkable effi ciency Similarly hormones that reduce the infl ammation normally associated with injury circulate at high levels If the body s all out eff ort to combat stress fails and the stress persists the individual moves into the exhaustion stage At this point the wear and tear on the body takes its toll the person might collapse in a state of exhaustion and vulnerability to disease increases Serious possibly irreversible damage to the body such as a heart attack or even death may occur Interest in links between the immune system and stress spawned a new fi eld of scientifi c inquiry psychoneuroimmunology which explores connections among psychological factors such as attitudes and emotions the nervous system and the immune system Th e immune system and the central nervous system are similar in their modes of receiving recognizing and integrating signals from the external environment Sternberg Gold 1996 Th e central nervous system and the immune system both possess sensory elements which receive information from the environment and other parts of the body and motor elements which carry out an appropriate response Both systems also rely on chemical mediators for communication CRH the hormone discussed above is shared by the central nervous system and the immune system uniting the stress and immune responses Suppression of Immune system could happen in three ways The first way Immune system is suppressed is by the stressor going through hypothalamus to putiatry gland and adrenal cortex The second way Immune system is suppressed is by the stressor going through hypothalamus to sympathetic nervous system and adrenal medulla The third way Immune system is suppressed is by the stressor going through hypothalamus to sympathetic nervous system and lymph nodes Cortisol the primary stress hormone increases sugars glucose in the bloodstream enhances your brain s use of glucose and increases the availability of substances that repair tissues Catecholamine any of a group of sympathomimetic amines including dopamine epinephrine and norepinephrine the aromatic portion of whose molecule is catechol In the human body the most abundant catecholamines are epinephrine adrenaline norepinephrine noradrenaline and dopamine all of which are produced from phenylalanine and tyrosine Release of the hormones epinephrine and norepinephrine from the adrenal medulla of the adrenal glands is part of the fight or flight response Nerves of Sympathetic part of Autonomic nervous system go directly to the lymph nodes to suppress lymphocytes which are small white blood cells that bear the major responsibility for carrying out the activities of the immune system Time pattern is different for different adrenal hormones Adrenalin Stress by this hormone is depended upon the stressor itself meaning if stressor goes down then adrenal hormones would go down Non Adrenalin Stress Rises during stressor and continues to rise after stressor removal Corticosteroids Rises during stressor and shows very slow decline after stressor removal Frankenhaeuser 1975 studied groups of workers such as sawyers who have to cut timber into predetermined sizes These jobs were very dull and repetitive and workers had little control over the pace of their work as it is determined by the machine The work cycle was about 10 seconds long so that decisions had to be made very quickly Finally in a very noisy environment social contact was minimal Predictably it was found that these workers had high levels of stress hormones Compared with other workers they had high rates of headaches higher blood pressure and gastrointestinal disorders such as ulcers Frankenhaeuser et al 1976 compared boys and girls taking examinations and found that boys showed a more rapid rise in stress hormone levels that took longer to return to normal Performance in the exam was similar as was reported levels of stress This finding is echoed in a number of studies men show more arousal when stressed than