Fondements physiologiques du stress

Stress triggers a physiological response involving the activation of two critical systems: the sympathetic nervous system and the hypothalamic-pituitary-adrenal, or HPA axis.

The initial perception of stress activates the sympathetic nervous system, which releases adrenaline from the adrenal glands.

Adrenaline induces immediate "fight-or-flight" responses, such as increased heart rate and respiration, which prepare the body for action.

Simultaneously, the HPA axis—operating more slowly than the sympathetic nervous system— initiates its own set of reactions to manage stress.

The hypothalamus releases the corticotropin-releasing factor, or CRF, prompting the pituitary gland to release the adrenocorticotropic hormone, or ACTH.

ACTH then travels to the adrenal glands, stimulating the release of various hormones, including cortisol, which is crucial for coping with stress.

Cortisol, often labeled the “stress hormone,” affects nearly all organs, providing a surge of energy to tackle the immediate challenge.

This coordinated response between adrenaline and cortisol equips the body to either confront or escape the threat effectively.