The Stress

Stress is associated with the state that arises from events that cause overwhelm or distress. It indicates an alarm reaction in the body triggered by an external stimulus, thus becoming an adaptation of the organism to the modification of its internal homeostasis caused by a stressor agent.

The phases described by Selye are three:

1. Alarm: the organism mobilizes its defenses by producing adrenaline and noradrenaline (Hormones of the central and peripheral nervous system that increase blood pressure and heart rate and act as neurotransmitters).

2. Resistance: if stress persists, the organism increases cortisol production, a potent anti-inflammatory, but with the side effect of depressing the immune system.

3. Exhaustion: the exhaustion of the adrenal gland is recorded, and the experimental animal, no longer protected by cortisol, dies. A fundamental aspect of the adaptation response: stimuli are registered by our senses and processed by the brain.

The mechanism is more or less as follows: an external (or internal) agent stimulates the receptors of touch, taste, smell, sight, or hearing (one alone or frequently, all together), therefore producing a sensation that is, by definition, a subjective phenomenon due to the stimulation of a sensory organ.

The perceived material is sent through the nervous system to our brain, and only here does the sensation get decoded. The brain, in the decoding process, proceeds by analogy, tending to assimilate different things and situations based on similarity, with a process of generalization that is very useful for learning but can sometimes create problems.

Once the perception has been made (everything happens in a few instants), the organism prepares to respond to the event, and if it is assessed as stressful, the hypothalamic-pituitary-adrenal axis is activated. At this point, we can draw some conclusions: in the case of ingestion of poison, the assault of a virus, or the presence of an environmental stimulus like excessive cold or heat, we can objectively interpret the situation as stressful, even though there are very different individual responses (some tolerate heat well but poorly tolerate cold, some are immune to the assault of certain viruses, etc.).

In the case of psychological stress, i.e., when we find ourselves in an unpleasant situation for any reason, the perception we have of the event is fundamental in establishing the type of response.

The brain, after receiving information from the sense organs, interprets the material by comparing it with what was previously stored in memory and encodes it by analogy. For example, being in front of an audience for a concert can be assimilated to public speaking, or taking an exam, etc. If the emotional brain believes that the event is a threat, it activates the hypothalamic-pituitary-adrenal axis.