Selye's General Adaptation Syndrome

Selye's General Adaptation Syndrome - Anhother important early contribution to the field of stress is Hans Selye's (1956, 1976) work on the general adaptation syndrome. Although Selye initially intended to explore the effects of sex hormones on physiological functioning, he became interested in the stressful impact his interventions seemed to have. Accordingly, he exposed rats to a variety of stressors-such as extreme cold and fatigue and observed their physiological responding. In particular, they all led to an enlarged adrenal cortex, shrinking of the thymus and lymph glands, and ulceration of the stomach and duodenum. Thus, whereas Cannon's work explored adrenomedullary responses to stress specifically, catecholamin secretion Selye's work more closely explored adrenocortical responses to stress.

General Adaptations Stages

From these observation, selye (1956) devloped his concept of the general adaptation sydrome. He argued that, when an organism confronts a stressor, it mobilizes it self for action. The respose it self is nonspecific with respect to the stressor; that is, regardless of the cause of the threat, the individual will respond with the same physiological pattern of reactions. Over time. with repeated or prolonged exposure to stress, there will be wear and tear on the system.

Adaptation Syndrom

The general adaptation syndrome consists of three phases, In the first phase, alarm, the organism becomes mobilized to meet the threat. In the second phase, resistance, the organism makes efforts to cope with the threat, as through confrontation. The third phase, exhaustion, occurs if the organism fails to evercome the threat and depletes its physiological resources in the process of trying. These phases are pictured in figure.

General Adaptation Syndrom

The subtantial impact of Selye's model on the field of stress continues to be felt today. One reason is that it offers a general theory of reactions to a wide variety of stressors over time. As such, it provides a way of thonking about the interplay of physiological and environmental factors. Second, it posits physiological mechanism for the stress-illness relationship. Specifically, Selye believed that repeated or prolonged exhaustion of resources, the third phase of the syndrome, is responsible for the physiological damage that lays the groundwork for desease. In fact, prolonged to repeated stress has been implicated in a broad array of disorders, such as cardiovascular disease, arthiritis, hypertension, and immune-releated deficiencies.