Phase 3 – Exhaustion — Page 129, Lesson 203

I want to walk you through the stress chapter, picking up where the body's response to prolonged stress can become dangerous. Let's start with the effect of stress hormones on memory. The stress hormone adrenaline — and cortisol — also acts on the brain to improve the memory of stress situations. That's why we remember these events particularly intensely. But there's a critical warning here: if an individual is exposed to stress for too long, his or her energy resources become depleted. That depletion leads us into the third phase of the General Adaptation Syndrome. Phase 3 – Exhaustion. This occurs over a variable period — it doesn't happen all at once — and it will normally affect only specific parts of the body, not the whole system simultaneously. With rest, this exhaustion stage is temporary. But if it's allowed to continue without respite, it can result in death, because the defence mechanism completely shuts down. That's the ultimate limit of the body's ability to cope. Now, the stress hormones — adrenaline and cortisol — generate waste matter that must be eliminated. This is not an easy process, and some secondary effects may occur. If the stress situation is coped with successfully, or if the stressors are removed, the body will gradually return to its normal state. That normal state is called the homeostatic state — the balanced, stable internal condition the body tries to maintain. It's important to note that stress may be "good" or "bad". Most stressors increase what we call the arousal level — the general state of alertness and activation in the nervous system. We'll see the relationship between arousal and performance in a moment. Let's now look at the three reactions of the General Adaptation Syndrome. These are the three distinct ways the body responds during the stress process. First, the Psychological Reaction: this is where the brain registers fear, alarm, or crisis. It's the mental recognition that something is wrong. Second, the Psychosomatic Reaction: during this reaction, the brain triggers the release of hormones, adrenaline, and sugars into the blood. Notice the term 'psychosomatic' — it links the mind (psyche) to the body (soma), because the brain's perception of stress directly causes physical chemical changes. Third, the Somatic Reaction: this is the responses of the various organs of the body to the hormonal and chemical releases. 'Somatic' refers to the body itself — the organs doing what the hormones tell them to do. Now, what causes all this? Stress factors, also called stressors. The figure on this page — Figure 7.3 — illustrates, in general terms, some of the possible stressors to which we may be exposed. Let me list them from the diagram so you have them clearly: money worries, lack of experience, low humidity, vibration, emergency, heat, health, sexual problems, domestic problems, noise, lack of training, workload, cold, moving house, bereavement, and promotion. Notice that promotion is listed as a stressor too — that's the 'good stress' I mentioned earlier. Even positive events increase arousal and require adaptation. That figure shows a model of stress and coping, and the feedback mechanism is of great importance — we'll build on that as we go.