What is the Origin of HPA Axis and Stress?

The name is an acronym derived from the three key endocrine glands involved: the Hypothalamus, the Pituitary gland, and the Adrenal glands. The understanding of this interconnected system as the primary regulator of the stress response was formalized in the mid-20th century, building upon Hans Selye's pioneering work on the General Adaptation Syndrome.

What is the Mechanism of HPA Axis and Stress?

A perceived stressor triggers the hypothalamus to release Corticotropin-Releasing Hormone (CRH), which stimulates the pituitary gland to secrete Adrenocorticotropic Hormone (ACTH). ACTH then travels to the adrenal cortex, prompting the release of cortisol. Cortisol, in turn, acts on target tissues and provides negative feedback to the hypothalamus and pituitary, thereby shutting down the stress response once the threat is mitigated.

HPA Axis and Stress

Meaning

The Hypothalamic-Pituitary-Adrenal (HPA) axis is a complex neuroendocrine feedback loop that represents the body’s central stress response system. This intricate communication pathway regulates the secretion of glucocorticoids, most notably cortisol, which is essential for mediating physiological and behavioral adaptations to perceived stressors. Chronic activation or dysregulation of this axis is a core driver of stress-related pathology.