You might have noticed by now that I like to break down everything to it's simplest forms. Today, I'm tackling stress. The following document contains a series of paragraphs that I believe best helps explain the phenomenon.
"Stress is simply a reaction to a stimulus that disturbs our physical or mental equilibrium. In other words, it's an omnipresent part of life. A stressful event can trigger the “fight-or-flight” response, causing hormones such as adrenaline and cortisol to surge through the body. A little bit of stress, known as “acute stress,” can be exciting—it keeps us active and alert. But long-term, or “chronic stress,” can have detrimental effects on health. You may not be able to control the stressors in your world, but you can alter your reaction to them. Cortisol is a steroid hormone, belonging to a broader class of steroids called glucocorticoids, produced by the adrenal gland and secreted during a stress response. Its primary function is to redistribute energy (glucose) to regions of the body that need it most (i.e., the brain and major muscles during a fight-or-flight situation). As a part of the body’s fight-or-flight response, cortisol also acts to suppress the body’s immune system. Cortisol is synthesized from cholesterol in the adrenal cortex. Its primary function is to increase blood sugar through gluconeogenesis, suppress the immune system and aid in fat and protein metabolism.
There is likely a connection between stress and illness. Theories of the stress–illness link suggest that both acute and chronic stress can cause illness, and several studies found such a link. According to these theories, both kinds of stress can lead to changes in behavior and in physiology. Behavioral changes can be smoking and eating habits and physical activity. Physiological changes can be changes in sympathetic activation or hypothalamic pituitary adrenocorticoid activation, and immunological function. However, there is much variability in the link between stress and illness.
Studies have shown that perceived chronic stress and the hostility associated with Type A personalities are often associated with much higher risks of cardiovascular disease. This occurs because of the compromised immune system as well as the high levels of arousal in the sympathetic nervous system that occur as part of the body's physiological response to stressful events.
Experiments show that when healthy human individuals are exposed to acute laboratory stressors, they show an adaptive enhancement of some markers of natural immunity but a general suppression of functions of specific immunity. By comparison, when healthy human individuals are exposed to real-life chronic stress, this stress is associated with a biphasic immune response where partial suppression of cellular and humoral function coincides with low-grade, nonspecific inflammation.
Chronic stress is defined as a "state of prolonged tension from internal or external stressors, which may cause various physical manifestations – e.g., asthma, back pain, arrhythmias, fatigue, headaches, HTN, irritable bowel syndrome, ulcers, and suppress the immune system". Chronic stress takes a more significant toll on the body than acute stress does. It can raise blood pressure, increase the risk of heart attack and stroke, increase vulnerability to anxiety and depression, contribute to infertility, and hasten the aging process. For example, results of one study demonstrated that individuals who reported relationship conflict lasting one month or longer have a greater risk of developing illness and show slower wound healing. Similarly, the effects that acute stressors have on the immune system may be increased when there is perceived stress and/or anxiety due to other events. For example, students who are taking exams show weaker immune responses if they also report stress due to daily hassles. While responses to acute stressors typically do not impose a health burden on young, healthy individuals, chronic stress in older or unhealthy individuals may have long-term effects that are detrimental to health.
Studies revealing the relationship between the immune system and the central nervous system indicate that stress can alter the function of the white blood cells involved in immune function known as lymphocytes and macrophages. People undergoing stressful life events, such as marital turmoil or bereavement, have a weaker lymphoproliferative response. People in distressed marriages have also been shown to have greater decreases in cellular immunity functioning over time when compared to those in happier marriages. After antigens initiate an immune response, these white blood cells send signals, composed of cytokines and other hormonal proteins, to the brain and neuroendocrine system.Cytokines are molecules involved with cell signaling.
Cortisol, a hormone released during stressful situations, affects the immune system greatly by preventing the production of cytokines. During chronic stress, cortisol is over produced, causing fewer receptors to be produced on immune cells so that inflammation cannot be ended. A study involving cancer patient’s parents confirmed this finding. Blood samples were taken from the participants. Researchers treated the samples of the parents of cancer patients with a cortisol-like substance and stimulated cytokine production. Cancer patient parents’ blood was significantly less effective at stopping cytokine from being produced.
The immune system also plays a role in stress and the early stages of wound healing. It is responsible for preparing the tissue for repair and promoting recruitment of certain cells to the wound area. Consistent with the fact that stress alters the production of cytokines, Graham et al. found that chronic stress associated with care giving for a person with Alzheimer’s Disease leads to delayed wound healing. Results indicated that biopsy wounds healed 25% more slowly in the chronically stressed group, or those caring for a person with Alzheimer’s disease.
Even though psychological stress is often connected with illness or disease, most healthy individuals can still remain disease-free after confronting chronic stressful events. Also, people who do not believe that stress will affect their health do not have an increased risk of illness, disease, or death. This suggests that there are individual differences in vulnerability to the potential pathogenic effects of stress; individual differences in vulnerability arise due to both genetic and psychological factors. In addition, the age at which the stress is experienced can dictate its effect on health. Research suggests chronic stress at a young age can have lifelong impacts on the biological, psychological, and behavioral responses to stress later in life.
In animals, stress contributes to the initiation, growth, and metastasis of select tumors, but studies that try to link stress and cancer incidence in humans have had mixed results. This can be due to practical difficulties in designing and implementing adequate studies.
Homeostasis is a concept central to the idea of stress. In biology, most biochemical processes strive to maintain equilibrium (homeostasis), a steady state that exists more as an ideal and less as an achievable condition. Environmental factors, internal or external stimuli, continually disrupt homeostasis; an organism’s present condition is a state of constant flux moving about a homeostatic point that is that organism’s optimal condition for living. Factors causing an organism’s condition to diverge too far from homeostasis can be experienced as stress. A life-threatening situation such as a major physical trauma or prolonged starvation can greatly disrupt homeostasis. On the other hand, an organism’s attempt at restoring conditions back to or near homeostasis, often consuming energy and natural resources, can also be interpreted as stress.
Stress can have many profound effects on the human biological systems. Biology primarily attempts to explain major concepts of stress using a stimulus-response paradigm, broadly comparable to how a psychobiological sensory system operates. The central nervous system (brain and spinal cord) plays a crucial role in the body's stress-related mechanisms. Whether one should interpret these mechanisms as the body’s response to a stressor or embody the act of stress itself is part of the ambiguity in defining what exactly stress is. Nevertheless, the central nervous system works closely with the body’s endocrine system to regulate these mechanisms. The sympathetic nervous system becomes primarily active during a stress response, regulating many of the body’s physiological functions in ways that ought to make an organism more adaptive to its environment.
The brain plays a critical role in the body’s perception of and response to stress. However, pinpointing exactly which regions of the brain are responsible for particular aspects of a stress response is difficult and often unclear. Understanding that the brain works in more of a network-like fashion carrying information about a stressful situation across regions of the brain (from cortical sensory areas to more basal structures and vice versa) can help explain how stress and its negative consequences are heavily rooted in neural communication dysfunction.
The hypothalamus is a small portion of the brain located below the thalamus and above the brainstem. One of its most important functions is to help link together the body’s nervous and endocrine systems. This structure has many bidirectional neural inputs and outputs from and to various other brain regions. These connections help to regulate the hypothalamus’ ability to secrete hormones into the body’s blood stream, having far-reaching and long-lasting effects on physiological processes such as metabolism. During a stress response, the hypothalamus secretes various hormones, namely corticotropin-releasing hormone, which stimulates the body’s pituitary gland and initiates a heavily regulated stress response pathway.
The amygdala is a small, "almond"-shaped structure, two of which are located bilaterally and deep within the medial temporal lobes of the brain. The amygdalae are part of the brain’s limbic system, with projections to and from the hypothalamus, hippocampus, and locus coeruleus among other areas. Thought to play a role in the processing of emotions, the amygdalae have been implicated in modulating stress response mechanisms, particularly when feelings of anxiety or fear are involved.
The hippocampus is a structure located bilaterally, deep within the medial temporal lobes of the brain, just below each amygdala, and is a part of the brain’s limbic system. The hippocampus is thought to play an important role in memory formation. There are numerous connections to the hippocampus from the cerebral cortex, hypothalamus, and amygdala, among other regions. During stress, the hippocampus is particularly important, in that cognitive processes such as prior memories can have a great influence on enhancing, suppressing, or even independently generating a stress response. The hippocampus is also an area in the brain that is susceptible to damage brought upon by chronic stress.
The prefrontal cortex, located in the frontal lobe, is the anterior-most region of the cerebral cortex. An important function of the prefrontal cortex is to regulate cognitive processes including planning, attention and problem solving through extensive connections with other brain regions. The prefrontal cortex can become impaired during the stress response.
The raphe nucleus is an area located in the pons of the brainstem that is the principal site of the synthesis of the neurotransmitter serotonin, which plays an important role in mood regulation, particularly when stress is associated with depression and anxiety. Projections extend from this region to widespread areas across the brain, namely the hypothalamus, and are thought to modulate an organism's circadian rhythm and sensation of pain among other processes.
The spinal cord plays a critical role in transferring stress response neural impulses from the brain to the rest of the body. In addition to the neuroendocrine blood hormone signaling system initiated by the hypothalamus, the spinal cord communicates with the rest of the body by innervating the peripheral nervous system. Certain nerves that belong to the sympathetic branch of the central nervous system exit the spinal cord and stimulate peripheral nerves, which in turn engage the body’s major organs and muscles in a fight-or-flight manner.
The pituitary gland is a small organ that is located at the base of the brain just under the hypothalamus. This gland releases various hormones that play significant roles in regulating homeostasis. During a stress response, the pituitary gland releases hormones into the blood stream, namely adrenocorticotropic hormone, which modulates a heavily regulated stress response system. Adrenocorticotropic hormone is the hormone secreted by the anterior lobe of the pituitary gland into the body’s blood stream that stimulates the cortex of the adrenal gland by binding to its adrenocorticotropic hormone-receptors, thus causing the adrenal gland to release cortisol.
The adrenal gland is a major organ of the endocrine system that is located directly on top of the kidneys and is chiefly responsible for the synthesis of stress hormones that are released into the blood stream during a stress response. Cortisol is the major stress hormone released by the adrenal gland. Cortisol can weaken the activity of the immune system. Cortisol prevents the proliferation of T-cells by rendering the interleukin-2 producer T-cells unresponsive to interleukin-1 (IL-1), and unable to produce the T-cell growth factor. Cortisol also has a negative-feedback effect on interleukin-1. IL-1 must be especially useful in combating some diseases; however, endotoxic bacteria have gained an advantage by forcing the hypothalamus to increase cortisol levels (forcing the secretion of CRH hormone, thus antagonizing IL-1). The suppressor cells are not affected by glucosteroid response-modifying factor (GRMF), so the effective setpoint for the immune cells may be even higher than the setpoint for physiological processes (reflecting leukocyte redistribution to lymph nodes, bone marrow, and skin). Rapid administration of corticosterone (the endogenous Type I and Type II receptor agonist) or RU28362 (a specific Type II receptor agonist) to adrenalectomized animals induced changes in leukocyte distribution. Natural killer cells are not affected by cortisol.
In addition to the locus coeruleus existing as a source of the neurotransmitter norepinephrine within the central nervous system, the adrenal gland can also release norepinephrine during a stress response into the body’s blood stream, at which point norepinephrine acts as a hormone in the endocrine system. Norepinephrine serves as the primary chemical messenger of the central nervous system’s sympathetic branch that prepares the body for fight-or-flight response.
Coping with Stress
Responses to stress include adaptation, psychological coping such as stress management, anxiety, and depression. Over the long term, distress can lead to diminished health and/or increased propensity to illness; to avoid this, stress must be managed.
Stress management encompasses techniques intended to equip a person with effective coping mechanisms for dealing with psychological stress, with stress defined as a person's physiological response to an internal or external stimulus that triggers the fight-or-flight response. Stress management is effective when a person uses strategies to cope with or alter stressful situations.
There are several ways of coping with stress, such as controlling the source of stress or learning to set limits and to say "no" to some of the demands that bosses or family members may make.
A person's capacity to tolerate the source of stress may be increased by thinking about another topic such as a hobby, listening to music, or spending time in a wilderness.
A way to control stress is first dealing with what is causing the stress if it is something the individual has control over. Other methods to control stress and reduce it can be: to not procrastinate and leave tasks for last minute, do things you like, exercise, do breathing routines, go out with friends, and take a break. Having support from a loved one also helps a lot in reducing stress.
Social support helps reduce stress but even more if the support is from a loved one."
"Stress is simply a reaction to a stimulus that disturbs our physical or mental equilibrium. In other words, it's an omnipresent part of life. A stressful event can trigger the “fight-or-flight” response, causing hormones such as adrenaline and cortisol to surge through the body. A little bit of stress, known as “acute stress,” can be exciting—it keeps us active and alert. But long-term, or “chronic stress,” can have detrimental effects on health. You may not be able to control the stressors in your world, but you can alter your reaction to them. Cortisol is a steroid hormone, belonging to a broader class of steroids called glucocorticoids, produced by the adrenal gland and secreted during a stress response. Its primary function is to redistribute energy (glucose) to regions of the body that need it most (i.e., the brain and major muscles during a fight-or-flight situation). As a part of the body’s fight-or-flight response, cortisol also acts to suppress the body’s immune system. Cortisol is synthesized from cholesterol in the adrenal cortex. Its primary function is to increase blood sugar through gluconeogenesis, suppress the immune system and aid in fat and protein metabolism.
There is likely a connection between stress and illness. Theories of the stress–illness link suggest that both acute and chronic stress can cause illness, and several studies found such a link. According to these theories, both kinds of stress can lead to changes in behavior and in physiology. Behavioral changes can be smoking and eating habits and physical activity. Physiological changes can be changes in sympathetic activation or hypothalamic pituitary adrenocorticoid activation, and immunological function. However, there is much variability in the link between stress and illness.
Studies have shown that perceived chronic stress and the hostility associated with Type A personalities are often associated with much higher risks of cardiovascular disease. This occurs because of the compromised immune system as well as the high levels of arousal in the sympathetic nervous system that occur as part of the body's physiological response to stressful events.
Experiments show that when healthy human individuals are exposed to acute laboratory stressors, they show an adaptive enhancement of some markers of natural immunity but a general suppression of functions of specific immunity. By comparison, when healthy human individuals are exposed to real-life chronic stress, this stress is associated with a biphasic immune response where partial suppression of cellular and humoral function coincides with low-grade, nonspecific inflammation.
Chronic stress is defined as a "state of prolonged tension from internal or external stressors, which may cause various physical manifestations – e.g., asthma, back pain, arrhythmias, fatigue, headaches, HTN, irritable bowel syndrome, ulcers, and suppress the immune system". Chronic stress takes a more significant toll on the body than acute stress does. It can raise blood pressure, increase the risk of heart attack and stroke, increase vulnerability to anxiety and depression, contribute to infertility, and hasten the aging process. For example, results of one study demonstrated that individuals who reported relationship conflict lasting one month or longer have a greater risk of developing illness and show slower wound healing. Similarly, the effects that acute stressors have on the immune system may be increased when there is perceived stress and/or anxiety due to other events. For example, students who are taking exams show weaker immune responses if they also report stress due to daily hassles. While responses to acute stressors typically do not impose a health burden on young, healthy individuals, chronic stress in older or unhealthy individuals may have long-term effects that are detrimental to health.
Studies revealing the relationship between the immune system and the central nervous system indicate that stress can alter the function of the white blood cells involved in immune function known as lymphocytes and macrophages. People undergoing stressful life events, such as marital turmoil or bereavement, have a weaker lymphoproliferative response. People in distressed marriages have also been shown to have greater decreases in cellular immunity functioning over time when compared to those in happier marriages. After antigens initiate an immune response, these white blood cells send signals, composed of cytokines and other hormonal proteins, to the brain and neuroendocrine system.Cytokines are molecules involved with cell signaling.
Cortisol, a hormone released during stressful situations, affects the immune system greatly by preventing the production of cytokines. During chronic stress, cortisol is over produced, causing fewer receptors to be produced on immune cells so that inflammation cannot be ended. A study involving cancer patient’s parents confirmed this finding. Blood samples were taken from the participants. Researchers treated the samples of the parents of cancer patients with a cortisol-like substance and stimulated cytokine production. Cancer patient parents’ blood was significantly less effective at stopping cytokine from being produced.
The immune system also plays a role in stress and the early stages of wound healing. It is responsible for preparing the tissue for repair and promoting recruitment of certain cells to the wound area. Consistent with the fact that stress alters the production of cytokines, Graham et al. found that chronic stress associated with care giving for a person with Alzheimer’s Disease leads to delayed wound healing. Results indicated that biopsy wounds healed 25% more slowly in the chronically stressed group, or those caring for a person with Alzheimer’s disease.
Even though psychological stress is often connected with illness or disease, most healthy individuals can still remain disease-free after confronting chronic stressful events. Also, people who do not believe that stress will affect their health do not have an increased risk of illness, disease, or death. This suggests that there are individual differences in vulnerability to the potential pathogenic effects of stress; individual differences in vulnerability arise due to both genetic and psychological factors. In addition, the age at which the stress is experienced can dictate its effect on health. Research suggests chronic stress at a young age can have lifelong impacts on the biological, psychological, and behavioral responses to stress later in life.
In animals, stress contributes to the initiation, growth, and metastasis of select tumors, but studies that try to link stress and cancer incidence in humans have had mixed results. This can be due to practical difficulties in designing and implementing adequate studies.
Homeostasis is a concept central to the idea of stress. In biology, most biochemical processes strive to maintain equilibrium (homeostasis), a steady state that exists more as an ideal and less as an achievable condition. Environmental factors, internal or external stimuli, continually disrupt homeostasis; an organism’s present condition is a state of constant flux moving about a homeostatic point that is that organism’s optimal condition for living. Factors causing an organism’s condition to diverge too far from homeostasis can be experienced as stress. A life-threatening situation such as a major physical trauma or prolonged starvation can greatly disrupt homeostasis. On the other hand, an organism’s attempt at restoring conditions back to or near homeostasis, often consuming energy and natural resources, can also be interpreted as stress.
Stress can have many profound effects on the human biological systems. Biology primarily attempts to explain major concepts of stress using a stimulus-response paradigm, broadly comparable to how a psychobiological sensory system operates. The central nervous system (brain and spinal cord) plays a crucial role in the body's stress-related mechanisms. Whether one should interpret these mechanisms as the body’s response to a stressor or embody the act of stress itself is part of the ambiguity in defining what exactly stress is. Nevertheless, the central nervous system works closely with the body’s endocrine system to regulate these mechanisms. The sympathetic nervous system becomes primarily active during a stress response, regulating many of the body’s physiological functions in ways that ought to make an organism more adaptive to its environment.
The brain plays a critical role in the body’s perception of and response to stress. However, pinpointing exactly which regions of the brain are responsible for particular aspects of a stress response is difficult and often unclear. Understanding that the brain works in more of a network-like fashion carrying information about a stressful situation across regions of the brain (from cortical sensory areas to more basal structures and vice versa) can help explain how stress and its negative consequences are heavily rooted in neural communication dysfunction.
The hypothalamus is a small portion of the brain located below the thalamus and above the brainstem. One of its most important functions is to help link together the body’s nervous and endocrine systems. This structure has many bidirectional neural inputs and outputs from and to various other brain regions. These connections help to regulate the hypothalamus’ ability to secrete hormones into the body’s blood stream, having far-reaching and long-lasting effects on physiological processes such as metabolism. During a stress response, the hypothalamus secretes various hormones, namely corticotropin-releasing hormone, which stimulates the body’s pituitary gland and initiates a heavily regulated stress response pathway.
The amygdala is a small, "almond"-shaped structure, two of which are located bilaterally and deep within the medial temporal lobes of the brain. The amygdalae are part of the brain’s limbic system, with projections to and from the hypothalamus, hippocampus, and locus coeruleus among other areas. Thought to play a role in the processing of emotions, the amygdalae have been implicated in modulating stress response mechanisms, particularly when feelings of anxiety or fear are involved.
The hippocampus is a structure located bilaterally, deep within the medial temporal lobes of the brain, just below each amygdala, and is a part of the brain’s limbic system. The hippocampus is thought to play an important role in memory formation. There are numerous connections to the hippocampus from the cerebral cortex, hypothalamus, and amygdala, among other regions. During stress, the hippocampus is particularly important, in that cognitive processes such as prior memories can have a great influence on enhancing, suppressing, or even independently generating a stress response. The hippocampus is also an area in the brain that is susceptible to damage brought upon by chronic stress.
The prefrontal cortex, located in the frontal lobe, is the anterior-most region of the cerebral cortex. An important function of the prefrontal cortex is to regulate cognitive processes including planning, attention and problem solving through extensive connections with other brain regions. The prefrontal cortex can become impaired during the stress response.
The raphe nucleus is an area located in the pons of the brainstem that is the principal site of the synthesis of the neurotransmitter serotonin, which plays an important role in mood regulation, particularly when stress is associated with depression and anxiety. Projections extend from this region to widespread areas across the brain, namely the hypothalamus, and are thought to modulate an organism's circadian rhythm and sensation of pain among other processes.
The spinal cord plays a critical role in transferring stress response neural impulses from the brain to the rest of the body. In addition to the neuroendocrine blood hormone signaling system initiated by the hypothalamus, the spinal cord communicates with the rest of the body by innervating the peripheral nervous system. Certain nerves that belong to the sympathetic branch of the central nervous system exit the spinal cord and stimulate peripheral nerves, which in turn engage the body’s major organs and muscles in a fight-or-flight manner.
The pituitary gland is a small organ that is located at the base of the brain just under the hypothalamus. This gland releases various hormones that play significant roles in regulating homeostasis. During a stress response, the pituitary gland releases hormones into the blood stream, namely adrenocorticotropic hormone, which modulates a heavily regulated stress response system. Adrenocorticotropic hormone is the hormone secreted by the anterior lobe of the pituitary gland into the body’s blood stream that stimulates the cortex of the adrenal gland by binding to its adrenocorticotropic hormone-receptors, thus causing the adrenal gland to release cortisol.
The adrenal gland is a major organ of the endocrine system that is located directly on top of the kidneys and is chiefly responsible for the synthesis of stress hormones that are released into the blood stream during a stress response. Cortisol is the major stress hormone released by the adrenal gland. Cortisol can weaken the activity of the immune system. Cortisol prevents the proliferation of T-cells by rendering the interleukin-2 producer T-cells unresponsive to interleukin-1 (IL-1), and unable to produce the T-cell growth factor. Cortisol also has a negative-feedback effect on interleukin-1. IL-1 must be especially useful in combating some diseases; however, endotoxic bacteria have gained an advantage by forcing the hypothalamus to increase cortisol levels (forcing the secretion of CRH hormone, thus antagonizing IL-1). The suppressor cells are not affected by glucosteroid response-modifying factor (GRMF), so the effective setpoint for the immune cells may be even higher than the setpoint for physiological processes (reflecting leukocyte redistribution to lymph nodes, bone marrow, and skin). Rapid administration of corticosterone (the endogenous Type I and Type II receptor agonist) or RU28362 (a specific Type II receptor agonist) to adrenalectomized animals induced changes in leukocyte distribution. Natural killer cells are not affected by cortisol.
In addition to the locus coeruleus existing as a source of the neurotransmitter norepinephrine within the central nervous system, the adrenal gland can also release norepinephrine during a stress response into the body’s blood stream, at which point norepinephrine acts as a hormone in the endocrine system. Norepinephrine serves as the primary chemical messenger of the central nervous system’s sympathetic branch that prepares the body for fight-or-flight response.
Coping with Stress
Responses to stress include adaptation, psychological coping such as stress management, anxiety, and depression. Over the long term, distress can lead to diminished health and/or increased propensity to illness; to avoid this, stress must be managed.
Stress management encompasses techniques intended to equip a person with effective coping mechanisms for dealing with psychological stress, with stress defined as a person's physiological response to an internal or external stimulus that triggers the fight-or-flight response. Stress management is effective when a person uses strategies to cope with or alter stressful situations.
There are several ways of coping with stress, such as controlling the source of stress or learning to set limits and to say "no" to some of the demands that bosses or family members may make.
A person's capacity to tolerate the source of stress may be increased by thinking about another topic such as a hobby, listening to music, or spending time in a wilderness.
A way to control stress is first dealing with what is causing the stress if it is something the individual has control over. Other methods to control stress and reduce it can be: to not procrastinate and leave tasks for last minute, do things you like, exercise, do breathing routines, go out with friends, and take a break. Having support from a loved one also helps a lot in reducing stress.
Social support helps reduce stress but even more if the support is from a loved one."
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