Final answer:
The body's response to stress occurs in three stages: alarm reaction, which triggers a fight-or-flight response, the stage of resistance, where the body adapts to continued stress, and the stage of exhaustion, where prolonged stress leads to severe health implications such as immune suppression and heart conditions.
Step-by-step explanation:
The Body's Response to Stress: The General Adaptation Syndrome
The body's response to stress follows three main stages known as the General Adaptation Syndrome (GAS), which were first identified by Hans Selye in 1936. These stages are the alarm reaction stage, the stage of resistance, and the stage of exhaustion.
Alarm Reaction Stage
During the alarm reaction stage, the body experiences an immediate reaction to a stressor, triggering a fight-or-flight response. This involves hormonal changes like the release of epinephrine and norepinephrine, leading to increased heart rate, elevated blood pressure, and heightened alertness to prepare for physical action.
Stage of Resistance
If the stressor persists, the body enters the stage of resistance. In this phase, the body attempts to adapt to the ongoing stress, maintaining a state of alertness but with less intensity compared to the initial reaction. Physiological changes such as altered digestive functions to maximize nutrient absorption can occur during this stage.
Stage of Exhaustion
The final phase, the stage of exhaustion, occurs when stress continues unabated over a long period. The body's prolonged effort to adapt depletes its resources, leading to symptoms such as depression, immune suppression, severe fatigue, and in severe cases, life-threatening conditions like heart attacks. This stage is marked by the overproduction of stress hormones like cortisol from the adrenal cortex.
These stages illustrate how prolonged or repeated stress can eventually lead to health issues, including disorders like hypertension and coronary artery disease.