Biological Basis of Stress
Stress can be defined as any type of change that causes physical, emotional or psychological strain. It is your body’s response to anything that requires attention or action. Stress is something that is experienced by everyone, no matter where they’re from or what their living conditions are. Many people think that stress is simply an emotion without considering the fact that stress is actually a physiological response meant to “protect” us from a stressor.
Fight or Flight?
Many physiological changes occur when met with a stressor, such as increased heart rate and dilated pupils, as well as many other changes that we don’t physically see. These changes occur because when your body senses a stressor, it believes that you’re in danger. When the body feels like it is facing danger, it is going to trigger a fight or flight reaction where you either are going to face this stressor head on, or you will try to avoid and run away from it. This stress response your body has evolved in humans for protection, and uses both the nervous system and endocrine system.
The Stress Response
This stress response is mediated by the hypothalamic-pituitary-adrenal (HPA) axis, which is a complex network of interactions between the brain and the endocrine system. The HPA axis is activated when the brain perceives a stressor, such as a loud noise or an upcoming deadline for an assignment. The hypothalamus, a region of the brain, releases the corticotropin-releasing hormone (CRH), which travels to the pituitary gland. The pituitary gland then releases the adrenocorticotropic hormone (ACTH), which travels to the adrenal glands. Lastly, the adrenal glands release the hormone cortisol, also known as the "stress hormone.”
Cortisol plays a key role in the stress response by increasing blood sugar levels, suppressing the immune system, and increasing heart rate and blood pressure. As mentioned earlier, these physiological changes help prepare the body for the "fight or flight" response. Once the stressor is gone, the HPA axis should return to a baseline level of activity. Stress is a biological process that evolved to protect us from danger, so instead of fearing stress and trying to prevent it, we should instead learn to accept the stress we feel.
Source:
Henry, J.P. (1992). Biological basis of the stress response. Integrative Physiological and Behavioral Science. 27(1), 66–83. https://doi.org/10.1007/BF02691093
Comments