<\/span>Understanding the body’s stress system<\/span><\/h2>\n\nUnderstanding stress and its effects on the body is of great importance. Our body is exposed to different types of stress on a daily basis, which can be described as stress. <\/p>\n\n
<\/span>Definition of stress and stressors<\/span><\/h3>\n\nStress is defined as a state in which the organism is confronted with increased demands that require an adaptive response. Stressors are the factors that trigger this reaction and can be of a physical, psychological or social nature. <\/p>\n\n
\nPhysical stressors include injury or cold.<\/li>\n\n\n\n Psychological stressors can arise from exam situations or conflicts.<\/li>\n\n\n\n Social stressors often result from isolation or excessive demands.<\/li>\n<\/ul>\n\n<\/span>Eustress vs. distress: the difference<\/span><\/h3>\n\nEustress describes positive stress that promotes well-being and contributes to growth and development. In contrast, distress describes negative stress that impairs well-being and can lead to health problems. <\/p>\n\n
<\/span>Biological significance of the stress response<\/span><\/h3>\n\nThe stress response has evolved as a survival mechanism that enables the rapid mobilization of energy reserves and increased alertness in dangerous situations. The organism’s ability to adapt to changing environmental conditions and maintain homeostasis in challenging situations are crucial for health. <\/p>\n\n
By understanding these mechanisms, we can better understand how stress affects our physical and mental well-being and the importance of healthy adaptation to stressful situations.<\/p>\n\n
<\/span>Basics of neuroendocrine stress regulation<\/span><\/h2>\n\nNeuroendocrine stress regulation is a complex system based on different axes. When the body is exposed to stress, these axes are activated to enable an appropriate stress response. <\/p>\n\n
<\/span>The hypothalamic-pituitary-adrenal axis<\/span><\/h3>\n\nThe hypothalamic-pituitary-adrenal axis (HPA axis) plays a central role in stress regulation. Stress stimuli stimulate the release of corticotropin-releasing hormone (CRH) from the hypothalamus, which in turn leads to the release of ACTH from the pituitary gland and ultimately cortisol from the adrenal cortex. <\/p>\n\n
Cortisol is the most important stress hormone in humans and has many effects on the body, including the regulation of metabolism and the suppression of the immune system.<\/p>\n\n
<\/span>The sympathetic-adrenal medullary axis<\/span><\/h3>\n\nThe sympathetic-adrenal axis mediates the rapid “fight-or-flight” response by activating the sympathetic nervous system. This leads to the release of adrenaline and noradrenaline from the adrenal medulla, which helps prepare the body for a stress response. <\/p>\n\n
<\/span>Neurotrophin neuropeptide axis<\/span><\/h3>\n\nThe neurotrophin-neuropeptide axis comprises various neuropeptides and neurotrophins that are released during stress. These molecules, such as substance P and BDNF, influence inflammatory processes, pain perception and neuronal plasticity and thus contribute to coping with stress. <\/p>\n\n
The three axes of neuroendocrine stress regulation work together to ensure a coordinated stress response and maintain the organism’s homeostasis. The activation of these axes is crucial for the function of the stress system and adaptation to stressful situations. <\/p>\n\n
<\/span>Hormones as stress mediators<\/span><\/h2>\n\nNeuroendocrine stress regulation involves a complex interaction of different hormones that are responsible for the body’s stress response. These hormones enable the body to react to various stressors and adapt to stressful situations. <\/p>\n\n
<\/span>Cortisol: the primary stress hormone<\/span><\/h3>\n\nCortisol is an important hormone that is produced in the adrenal cortex. It plays a central role in the mobilization of energy reserves through gluconeogenesis and the regulation of the immune system during stressful situations. During acute stress, the cortisol level in the blood rises, which is adaptive in the short term. However, a chronic increase can lead to health problems such as immunosuppression, muscle breakdown and cognitive impairment. <\/p>\n\n
<\/span>Adrenaline and noradrenaline: the fight-or-flight hormones<\/span><\/h3>\n\nAdrenaline and noradrenaline are released by the adrenal medulla during stress and mediate the classic “fight or flight” response. They increase the heart rate, dilate the bronchial tubes, increase blood flow to the skeletal muscles and mobilize glucose. The release of adrenaline can increase by up to 2500% of the resting level during extreme stress, while noradrenaline can increase by up to 800%. <\/p>\n\n
<\/span>CRH and ACTH: the control hormones<\/span><\/h3>\n\nCRH (corticotropin-releasing hormone) and ACTH (adrenocorticotropic hormone) act as superordinate control hormones of the stress axis. CRH is released by the hypothalamus and stimulates the release of ACTH from the pituitary gland, which in turn stimulates cortisol production in the adrenal cortex. These hormones play a decisive role in the regulation of the stress response. <\/p>\n\n
<\/span>Acute vs. chronic stress reaction<\/span><\/h2>\n\nThe body’s stress response can be divided into two categories: acute and chronic. These two forms of stress have different effects on the body and its functions. <\/p>\n\n
<\/span>Fight-or-flight reaction during acute stress<\/span><\/h3>\n\nThe acute stress response, also known as the “fight-or-flight” response, is an evolutionarily conserved response to immediate threats. It is characterized by the rapid activation of the sympathetic nervous system and the release of stress hormones such as adrenaline and noradrenaline. <\/p>\n\n
\nRapid redistribution of blood flow to the skeletal muscles and brain<\/li>\n\n\n\n Increase in heart rate and blood pressure<\/li>\n\n\n\n Changes in the metabolism for rapid energy supply<\/li>\n<\/ul>\n\n