Lynda W. Freeman
To comprehend the information concerning how life events modulate health, you must have a foundation in the "basics." This chapter covers these "basics," including (1) an overview of the lines of research that demonstrate the effects of stress on health; (2) an explanation of how immune cells are conditioned to respond in particular ways; (3) the delineation of how immune cells interact and communicate; and (4) a summary of how researchers assess immune competency in human subjects. Without some knowledge of these topics, you will be unable to understand, evaluate, and synthesize the outcomes of mind-body research. This chapter also serves as a mini-reference manual to which you can repeatedly refer as you study this text.
Physiologic and immunologic responses can become conditioned by exposure to certain stimuli, such as taste, touch, or heat; by certain chemicals, such as immunosuppressive drugs; and by events that ore emotionally meaningful or traumatic. The pathways by which these events occur are most clearly defined by an emerging interdisciplinary field called psychoneuroimmunology. Psychoneuroimmunology describes the interactions among behavior, neural and endocrine function, and immune processes.
There ore four lines of evidence for the mind's influence on the body: observational, physiologic, epidemiologic, and clinical. Observational evidence includes individual case studies of responses to otherwise neutral substances, such as patients who are allergic to flowers and become symptomatic at the sight of an artificial rose. Walter B. Cannon performed the original physiologic research. Cannon discovered the "fight-or-flight" response, defined as a physiologic response that occurs when the emotions of anger, fear, or rage are expressed. These emotions include increased adrenaline, elevated blood pressure and blood sugar, and accelerated heart rate. Epidemiologic research, dating from the 1960s, describes how psychosocial factors and patterns of illness are correlated. Clinical trials refer to the testing of immediate and ongoing health effects of stressful situations. Serious life changes such as divorce or job loss, distressing life events such as role conflicts and family stress, unhappiness or clinical depression, and social isolation were all found to be major risk factors for mortality from a wide variety of causes.
Most outcomes of mind-body research are evaluated by measuring the changes in values of immune cells and their by-products with the use of immune assays.
The immune system protects the body through its ability to recognize and respond to invaders. It uses specific and nonspecific defense systems. One way the immune system protects the body is with white blood cells and their by-products. White blood cells include neutrophils, lymphocytes, monocytes, eosinophils, and basophils. Neutrophils, eosinophils, and basophils are called granulocytes because they have granules that contain hydrogen peroxide—reducing agents, compound-splitting enzymes, and digestive enzyme—containing cells. Lymphocytes and monocytes