Final answer:
Selye's General Adaptation Syndrome (GAS) explains how organisms respond physiologically to stressors with a three-phase process: alarm reaction, stage of resistance, and stage of exhaustion, which can lead to health problems.
Step-by-step explanation:
Hans Selye's General Adaptation Syndrome (GAS) model is a key concept in understanding how organisms respond physiologically to stressors. The model outlines a three-stage process that organisms go through in response to a stressor: the alarm reaction, stage of resistance, and stage of exhaustion. Selye's research, which identified this universal response pattern regardless of the type of stressor, indicates that prolonged or repeated stress can contribute to various disorders, such as hypertension and coronary artery disease. While Selye's model focuses on the body's physical responses, it does not extensively address the psychological factors involved in stress.
During the alarm reaction stage, the body reacts to a threat with a series of physiological changes that provide energy to manage the situation, similar to Walter Cannon's fight-or-flight response. If the stressor persists, the body enters the stage of resistance, attempting to adapt and cope with the stress. Prolonged exposure to the stressor can lead to the final stage, stage of exhaustion, where the physical resources are depleted, making the body more susceptible to illness.