Final answer:
The three stages of Hans Selye's General Adaptation Syndrome (GAS) are (1) alarm reaction, (2) stage of resistance, and (3) stage of exhaustion, describing the physiological response to stress.
Step-by-step explanation:
Hans Selye developed the concept of the General Adaptation Syndrome (GAS), which describes the body's response to stress through a three-stage process. The three stages of GAS are: (1) alarm reaction, (2) stage of resistance, and (3) stage of exhaustion.
The alarm reaction is the body's immediate response to stress, analogous to the fight-or-flight response. It involves a cascade of physiological reactions that provide energy to manage the situation. Followed by this, if the exposure to the stressor continues, the body enters the stage of resistance, during which it adapts to the stressor while still being prepared to respond to stress. Finally, with prolonged stress, the stage of exhaustion occurs, where the body's resources are depleted, leading to increased vulnerability to health problems.