Chapter 5: Stress and Inflammatory Responses

Stress and Inflammatory Responses explores the foundational principles of steady state and the role of negative feedback loops in regulating vital functions like blood pressure and acid-base balance. A significant portion of the text is dedicated to Hans Selye’s General Adaptation Syndrome (GAS), detailing the three critical phases—alarm, resistance, and exhaustion—and the activation of the sympathetic-adrenal-medullary response (fight-or-flight) and the hypothalamic-pituitary pathway, which result in the release of catecholamines (epinephrine, norepinephrine) and corticosteroids (cortisol). The discussion extends to the field of psychoneuroimmunology, examining how stress impacts immune function and the potential for maladaptive responses leading to disease. Cognitive aspects are addressed through Lazarus’s theory of appraisal and coping, distinguishing between emotion-focused and problem-focused strategies. At the cellular level, the text categorizes adaptive changes such as atrophy, hypertrophy, hyperplasia, metaplasia, and dysplasia, while also investigating causes of cellular injury including hypoxia, nutritional imbalances, and physical agents. The chapter details the inflammatory response as a protective mechanism, outlining the vascular and cellular stages that produce the five cardinal signs of inflammation: redness, warmth, swelling, pain, and loss of function. Furthermore, it differentiates between acute and chronic inflammation and explains the reparative processes of regeneration versus replacement (scar tissue formation). Finally, the content emphasizes nursing management strategies for stress reduction, incorporating health-promotion assessments, social support enhancement, and relaxation techniques such as progressive muscle relaxation, the Benson relaxation response, and guided imagery to foster resilience and prevent stress-related illness.