Lise Alschuler, ND, FABNO
- SHARE
HPA Axis & Stress Response: Hypothalamic Pituitary Adrenal Axis
The hypothalamic pituitary adrenal (HPA) axis is our central stress response system. The HPA axis is an eloquent and every-dynamic intertwining of the central nervous system and endocrine system.
This system works in a fairly straight-forward manner. The HPA axis is responsible for the neuroendocrine adaptation component of the stress response. This response is characterized by hypothalamic release of corticotropin-releasing factor (CRF). CRF is also known as CRH or corticotropin-releasing hormone. When CRF binds to CRF receptors on the anterior pituitary gland, adrenocorticotropic hormone (ACTH) is released. ACTH binds to receptors on the adrenal cortex and stimulates adrenal release of cortisol. In response to stressors, cortisol will be released for several hours after encountering the stressor. At a certain blood concentration of cortisol this protection is ostensibly achieved and the cortisol exerts negative feedback to the hypothalamic release of CRF and the pituitary release of ACTH (negative feedback). At this point, systemic homeostasis returns.
With repeated exposure to stressors, the organism habituates to the stressor with repeated and sustained HPA axis activation. Therefore, it is important to support healthy cortisol levels in order to ensure the hypothalamus and pituitary glands maintain the appropriate level of sensitivity to the negative feedback of cortisol. Secretion of alarm chemicals such as epinephrine and norepinephrine from the adrenal medulla, as well as HPA axis activation persists along with the secretion of CRF, ACTH, and cortisol. Interestingly, with aging, the hypothalamus and pituitary are less sensitive to negative feedback from cortisol and both ACTH and cortisol levels rise as we age.1 Older women secrete more cortisol in response to stress than do older men. Young women, however, produce lower levels of cortisol in response to stress than do young men.
Under conditions of normal exposure to cortisol, our tissues only experience fleeting glimpses of the alarm catecholamines and cortisol. As we are addressing the various health consequences of stress, it is imperative to also address the axis of response itself. Restoring homeostasis to the HPA axis is the primary goal of integrative care.
REFERENCES
- Veldhuis JD, et al. Endocrinol Metab Clin North Am. 2013 Jun;42(2):201-25.
- Seeman TE, et al. Psychoneuroendocrinology. 2001;26(3):225
Last Updated:
12/03/2019
The Importance of Sleep
Sleep is one of the fundamental aspects of life as it allows the body to repair and rejuvenate itself. Sleep affects almost every tissue in the body by regulating various functions, including cognition, hormone production, immune function, appetite, breathing, blood pressure and cardiovascular health.
Read More
The Role Of Cortisol
The body adapts to stressful, or threatening, situations through the activation of neural mechanisms, mediated through the mid-brain and ultimately culminating in the release of stress hormones - primarily cortisol and epinephrine.
Read More
General Adaptation Syndrome (GAS) Stages
Hans Selye, MD, PhD, a Hungarian endocrinologist known as the "Father of Stress" was the first to give a scientific explanation for biological "stress". He eloquently explained his stress model, based on physiology and psychobiology, as the General Adaptation Syndrome (GAS), stating an event that threatens an organism’s well being, a stressor, leads to a three-stage bodily response.
Read More
Sleep Smart: Identifying Underlying Factors
Many factors, from internal root causes to external lifestyle circumstances, can contribute to poor sleep.
Read More
Utilizing Adaptogens
As we continue to shift our focus on supporting the entire hypothalamic pituitary adrenal axis rather than laser focusing on just the adrenal glands we can see the important role that stress has on the overall picture of health.
Read MoreFeatured Products
V Clear EPs 7630® Original
V Clear EPs 7630™ is an upper respiratory treatment containing a proprietary, homeopathic preparation of Pelargonium sidoides extract which addresses the underlying cause of symptoms to help speed recovery, and shorten the duration of upper respiratory irritations.
V Clear EPs 7630® Cherry
V Clear EPs 7630® is an upper respiratory treatment containing a proprietary, homeopathic preparation of Pelargonium sidoides 1X which addresses the underlying cause of symptoms to help speed recovery, and shorten the duration of upper respiratory irritations.
Detoxication Factors™
Supports healthy phase I and phase II detoxification pathways in the liver.*
UBQH™ (50mg)
Active, stabilized ubiquinol in an exclusive, clinically studied delivery system. UBQH™ provides the most active CoQ10, ubiquinol. UBQH™ is designed especially for those individuals whose DNA cannot properly process CoQ10 or those that are experiencing a natural decline in CoQ10 production associated with aging.