In previous posts we’ve seen the importance of stress in the mind-body connection of good health. Our primary stress management pathway is the hypothalamic-pituitary-adrenal (HPA) axis that signals the endocrine system to release hormones. The HPA axis responds to physical and mental challenges to maintain homeostasis in part by controlling the body’s cortisol level.
These hormones, particularly those produced by the thyroid and adrenals (cortisol), along with neurotransmitters and neuropeptides, directly affect the immune system and can increase or decrease cellular processes. Freeman and Lawlis found that certain hormones, such as cortisol and epinephrine, are released in higher amounts when an individual is under great stress. In addition, these hormones are known to depress T-cell activity, and thus one’s immune system (LINK TO SOURCE Freeman & Lawlis, 2001)
The immune system helps to maintain physical homeostasis. Stress-induced alterations in the immune system occur primarily in the spleen, lymph nodes, and lymphoid tissues. However, there are numerous components of the immune system that may be modified by stress hormones. Jacobs found that individuals who are under stress have an increased risk of developing autoimmune diseases. The most common stress-related autoimmune diseases are psoriasis, rheumatoid arthritis, and multiple sclerosis. (LINK TO SOURCE Jacobs, 2001,S83-S92)
With the solid footing in our understanding of the brain-immune, mind-body connections and functions, provided over the last several posts, we will next turn to discussion of the broader picture of the body’s response to stress and stress memory.