Stress helps you meet your daily challenges and motivates you to reach your goals, ultimately making you a smarter, happier, and healthier person. However when you are stressed, what body reactions or clinical manifestations do you often experience? After studying the endocrine system and the stress response, can you explain how these clinical manifestations occur?
These clinical manifestations occur mainly with the help of hormones produced by the endocrine system and the nerve impulses of the nervous system. When immersed in stressful environments, the body maintains homeostasis by stress response or general adaptation syndrome (GAS). It occurs in 3 stages namely: 1) fight-or-flight response, 2) resistance reaction, and 3) exhaustion. When a stimuli is detected, the hypothalamus initiates a nerve impulse to the sympathetic nervous system to mobilize the body's resources for physical activities. During fight-or-flight response, the brain, skeletal muscles, and the heart get the most glucose and oxygen while non-essential body functions during dangerous situations are inhibited. In contrast with the first stage, the resistance reaction is a longer-lasting response which consists of using CRH, GHRH, and TRH to stimulate the release of ACTH, hGH, and TSH respectively. Cortisol is a hormone released in adrenal cortex due to ACTH; its main functions are to increase glucose metabolism - produces ATP, provide stress resistance and reduce inflammation. When our body uses all the available resources for bodily functions, it enters exhaustion stage. When cortisol keeps on increasing to an amount more than the body needs, it can cause various pathological changes in the body. As such, cortisol production is decreased when elevated cortisol levels is detected by the body.
References:
Tortora, & Derrickson. (2012). Chapter 8: The Endocrine System. In Principles of anatomy and physiology (13th ed.). Pp 713-714.