General Adaptation Syndrome: Videos & Practice Problems

General adaptation syndrome, identified by Hans Selye, describes the body's physiological response to chronic stress through three phases: alarm, resistance, and exhaustion. The alarm phase triggers the sympathetic nervous system, leading to a low stress resistance. In the resistance phase, the body adapts, maintaining a stress response with decreased intensity. Finally, the exhaustion phase occurs when resources are depleted, resulting in negative health effects such as hypertension, gastrointestinal issues, and poor immune function. Understanding these phases is crucial for managing stress and its long-term consequences.

General Adaptation Syndrome

General adaptation syndrome (GAS) describes the physiological responses our bodies undergo during prolonged or chronic stress, a concept introduced by Hans Selye in 1956. Through experiments on rats, Selye identified three distinct phases: the alarm phase, the resistance phase, and the exhaustion phase. Understanding these phases is crucial for recognizing how stress impacts our health.

The first phase, the alarm phase, occurs immediately upon encountering a stressor. This phase triggers the sympathetic nervous system, initiating the fight or flight response. Physiologically, this results in increased heart rate, elevated blood pressure, and heightened respiration. During this phase, stress resistance is low, meaning the body struggles to adapt to the stressor, leading to significant physiological strain.

Following the alarm phase is the resistance phase, where the body begins to adapt to the ongoing stress. Although the stress response continues, its intensity diminishes, allowing the individual to function despite the stressor. For instance, during a long flight, while initial panic may subside, the body remains in a heightened state of alertness, albeit at a reduced level. This phase can last from hours to years, depending on the chronicity of the stressor, and during this time, stress resistance increases as the body learns to cope.

Eventually, if the stress persists, the body enters the exhaustion phase. Here, the body's resources become depleted, leading to physical wear and tear on organs and tissues. Stress resistance drops significantly, and individuals may experience severe health consequences. Chronic stress is linked to various health issues, including hypertension due to prolonged high blood pressure, gastrointestinal problems like irritable bowel syndrome (IBS) or ulcers from reduced blood flow to digestive organs, and type 2 diabetes from elevated blood glucose levels. Additionally, chronic stress can lead to muscle tension, headaches, and impaired immune function, making the body more susceptible to illness.

Recognizing these phases of general adaptation syndrome is essential for understanding the impact of stress on health and the importance of developing effective stress management strategies.

Example 1

General Adaptation Syndrome (GAS) describes the body's response to stress in three distinct phases: alarm, resistance, and exhaustion. Understanding these phases is crucial for recognizing how prolonged stress can impact health.

The alarm phase is the body's immediate reaction to a stressor, characterized by sympathetic activation. For instance, when Mikkel starts a new internship and is unexpectedly questioned about his qualifications in a team meeting, he experiences this initial alarm response. This situation triggers a fight-or-flight reaction, highlighting the body's readiness to confront the stressor.

As the stressor persists, the body enters the resistance phase. During this phase, Mikkel adapts to the ongoing stress by putting in extra hours to meet his boss's demands. Although he feels less anxious in meetings, the constant pressure to perform remains, indicating that while the intensity of the stress response has decreased, the stressor is still affecting him. This phase reflects the body's efforts to cope with and manage the stressor over time.

Finally, if the stress continues without relief, the body may reach the exhaustion phase. At the end of the semester, Mikkel submits his final report but feels rundown and suffers from regular tension headaches. These symptoms are common indicators of chronic stress, demonstrating that the body's resources have been depleted, leading to potential negative health consequences.

In summary, recognizing the stages of General Adaptation Syndrome helps in understanding how stress affects individuals and the importance of managing stress effectively to prevent reaching the exhaustion phase.

During which phase of general adaptation syndrome are you most susceptible to illness?

• A. Alarm Phase
• B. Resistance Phase
• C. Exhaustion Phase

Answer: (C)

Here’s what students ask on this topic:

What are the three stages of General Adaptation Syndrome?

The three stages of General Adaptation Syndrome, as identified by Hans Selye, are:

1. Alarm Phase: This is the initial reaction to a stressor, where the sympathetic nervous system activates the fight-or-flight response. Physiological changes include increased heart rate, blood pressure, and respiration. Stress resistance is low during this phase.

2. Resistance Phase: In this stage, the body adapts to the stressor. While the stress response continues, its intensity decreases, allowing the body to function under prolonged stress. Stress resistance is high during this phase.

3. Exhaustion Phase: If the stress persists for too long, the body’s resources become depleted. This leads to a drop in stress resistance and potential health issues such as hypertension, gastrointestinal problems, and weakened immune function.

How does chronic stress affect the immune system?

Chronic stress negatively impacts the immune system by suppressing its function. During prolonged stress, the body prioritizes immediate survival responses, such as increased heart rate and glucose levels, over long-term processes like immune defense. This suppression occurs because stress hormones, such as cortisol, reduce the production of white blood cells and inhibit inflammatory responses. Over time, this can lead to increased susceptibility to infections, slower wound healing, and a higher risk of developing chronic illnesses. Understanding this connection highlights the importance of stress management for maintaining a healthy immune system.

What happens during the alarm phase of General Adaptation Syndrome?

During the alarm phase of General Adaptation Syndrome, the body reacts to a stressor by activating the sympathetic nervous system, initiating the fight-or-flight response. This leads to physiological changes such as increased heart rate, elevated blood pressure, faster breathing, and heightened alertness. These changes prepare the body to either confront or escape the stressor. However, stress resistance is low during this phase, as the body is not yet adapted to the stress. This phase is typically short-lived and marks the immediate response to a perceived threat.

What are the health consequences of prolonged stress in the exhaustion phase?

Prolonged stress during the exhaustion phase can lead to significant health consequences due to the depletion of the body’s resources. Common issues include:

• Hypertension: Chronic high blood pressure from sustained stress responses.
• Gastrointestinal problems: Conditions like irritable bowel syndrome (IBS) or ulcers due to reduced blood flow to digestive organs.
• Type 2 Diabetes: Elevated blood glucose levels over time can impair insulin function.
• Muscle tension and headaches: Persistent stress can cause tension headaches and muscle pain.
• Weakened immune function: Reduced ability to fight infections and heal wounds.

These effects underscore the importance of managing stress to prevent long-term health complications.

How does the resistance phase help the body adapt to stress?

In the resistance phase of General Adaptation Syndrome, the body adapts to the stressor by maintaining a stress response at a reduced intensity. This phase is characterized by the body’s ability to function under prolonged stress. For example, while heart rate and blood pressure may remain elevated, they are lower than during the initial alarm phase. Stress resistance is high during this phase, as the body allocates resources to cope with the stressor. However, this adaptation is not sustainable indefinitely, and prolonged stress can lead to the exhaustion phase if not managed effectively.