Understanding How Stress
Affects the Physical Body
BRUCE S. RABIN
When an individual perceives something in the environment that is considered “stressful, ” specific regions of his or her brain are activated. As a result, neuronal pathways and hormonal centers release substances that may modify the function of the immune system.
The primary purpose of the immune system is defense against pathogenic microorganisms, with the goal of any immune response being neutralization and elimination of the infectious agents. The immune process involves a host of physiological changes that can be viewed as shifts in the equilibrium of the body, or alterations of homeostasis. The immune system works to restore homeostasis by identifying and eliminating internal aberrations (a malignant cell) or external invaders (viruses, bacteria, fungi).
The physiological response to stress also alters homeostasis and often impairs the ability of the immune system to function properly in its attempts to restore homeostasis. Stress may disturb homeostasis through responses to a variety of stimuli such as fear, anxiety, intense exercise, or pain. The stimulus that induces the disturbance of homeostasis is known as a “stressor. ”
This chapter provides a brief overview of the very complex nature of the brain's response to stress and the potential pathways that may be activated by stress that ultimately may influence immune function. It also briefly discusses potential paradigms by which belief systems may modify or buffer the stress response. However, detailed discussions of these paradigms are to be found in other chapters of this book.