How does the stress affect the immune response? The immune system is a network of glands, nodes, and organs. It protects the body from bacteria and viruses. It requires a constant supply of nutrients to maintain its function.
What can affect the immune system? Toxins in the environment, poor diet, lack of or excessive exercise, and, guess what? Stress.
“The HPA axis works in a straightforward manner of managing the neurological and endocrine systems to activate the fight-flight-freeze response, also known as the stress response.
When the fight-flight-freeze response is activated there is a release of corticotropin-releasing hormone, known as CRH. When this hormone binds to receptors in the pituitary gland it releases the ACTH (adrenocorticotropic) hormone.
This hormone then binds to the adrenal cortex, stimulating the release of cortisol from the adrenals. After a stressful event, in which the fight-flight-freeze response is activated, cortisol is continuously released throughout the body for several hours.
The reduction of what we perceive as stress and anxiety can be modulated by yoga practice as it can modulate your stress response systems, as medical evidence has shown.
Modulating your stress response means emphasizing the parasympathetic nervous system, the rest and digest response, over the sympathetic nervous system, the stress response.
The physiological benefits of that modulation are easy to understand now that you have read the differences between the two branches of the autonomic nervous system in Chapter 3: reducing the heart rate, lowering blood pressure, easing breathing and also increasing the heart rate variability, an indicator of the body’s ability to respond to stress more flexibly, an ability First Responders need to develop.“