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tress, adaptation, and their relationship to health
are a frequent topic of discussion. The human
body and mind respond to stress by activating a com-
plex repertoire of physiologic and behavioral adap-
tive responses which, if inadequate or excessive, may
affect emotional behavior and have adverse effects on
physiologic functioning. Stress may contribute directly
to the production or exacerbation of a disease, or it
may contribute to the development of behaviors such
as smoking, overeating, and drug abuse that increase
risk of disease.
The content in this chapter has been organized into
two sections: the first focuses on stress and adaptation
and the second on disorders of the stress response.
Stress and Adaptation
A variety of definitions have been ascribed to the phe-
nomenon of stress. The concept of stress has been
studied extensively by physiologists, psychologists, soci-
ologists, and members of the health care professions.
The nature of these disciplines and the individual work
of their members have led to rather disparate bodies of
knowledge about stress. Despite these disparities, the
concept of stress is commonly viewed within the con-
text of three major components: homeostasis, the stress
response, and adaptation to stress.
Homeostasis
The concepts of stress and adaptation have their origin
in the complexity of the human body and interactions
between the body’s cells and its many organ systems.
These interactions require that a level of homeostasis
or constancy be maintained during the many changes
that occur in the internal and external environments. In
effecting a state of constancy, homeostasis requires feed-
back control systems that regulate cellular function and
integrate functions of the different body systems.
Constancy of the Internal Environment
The environment in which body cells live is not the
external environment that surrounds the organism, but
S
Stress and
Adaptation
9
C h a p t e r
Stress and Adaptation
Homeostasis
Constancy of the Internal Environment
Control Systems
The Stress Response
Neuroendocrine Responses
Immune Responses
Adaptation to Stress
Control Mechanisms
Adaptive Mechanisms
Disorders of the Stress Response
Effects of Acute Stress
Effects of Chronic Stress
Posttraumatic Stress Disorder
Treatment of Stress Disorders
Progressive Muscle Relaxation Techniques
Guided Imagery
Music Therapy
Massage Therapy
Biofeedback
