A stressor is a chemical or biological agent, environmental condition, external stimulus or an event seen as causing stress to an organism. Psychologically speaking, a stressor can be events or environments that individuals might consider demanding, challenging, and/or threatening individual safety.
Events or objects that may trigger a stress response may include:
Inner peace (also known as peace of mind) refers to a deliberate state of psychological or spiritual calm maintained despite the presence of stressors. It is associated with a state of psychological "homeostasis" and the opposite of being stressed or anxious, and is considered to be a state where one's mind performs at an optimal level, regardless of outcomes. Peace of mind is thus generally associated with a state of contentment and emotional well-being including bliss, happiness and contentment.
Peace of mind, serenity, and calmness are descriptions of a disposition free from the effects of stress. In various cultural traditions, inner peace is regarded as a state of consciousness attainable through practices such as breathing exercises, prayer, meditation, tai chi or yoga. Many spiritual practices refer to this peace as an experience of knowing oneself.
In its broadest sense, social vulnerability is one dimension of vulnerability to multiple stressors and shocks, including abuse, social exclusion and natural hazards. Social vulnerability refers to the inability of people, organizations, and societies to withstand adverse impacts from multiple stressors to which they are exposed. These impacts are due in part to characteristics inherent in social interactions, institutions, and systems of cultural values.
Social vulnerability is an interdisciplinary topic that connects social, health, and environmental fields of study. As it captures the susceptibility of a system or an individual to respond to external stressors like pandemics or natural disasters, many studies of social vulnerability are found in risk management literature.
Filamentation is the anomalous growth of certain bacteria, such as Escherichia coli, in which cells continue to elongate but do not divide (no septa formation). The cells that result from elongation without division have multiple chromosomal copies.
In the absence of antibiotics or other stressors, filamentation occurs at a low frequency in bacterial populations (4–8% short filaments and 0–5% long filaments in 1- to 8-hour cultures). The increased cell length can protect bacteria from protozoan predation and neutrophil phagocytosis by making ingestion of cells more difficult. Filamentation is also thought to protect bacteria from antibiotics, and is associated with other aspects of bacterial virulence such as biofilm formation.
Stress, whether physiological, biological or psychological, is an organism's response to a stressor, such as an environmental condition or change in life circumstances. When stressed by stimuli that alter an organism's environment, multiple systems respond across the body. In humans and most mammals, the autonomic nervous system and hypothalamic-pituitary-adrenal (HPA) axis are the two major systems that respond to stress. Two well-known hormones that humans produce during stressful situations are adrenaline and cortisol.
The sympathoadrenal medullary axis (SAM) may activate the fight-or-flight response through the sympathetic nervous system, which dedicates energy to more relevant bodily systems to acute adaptation to stress, while the parasympathetic nervous system returns the body to homeostasis.
Neuroticism or negativity is a personality trait associated with negative emotions. It is one of the Big Five traits. People high in neuroticism experience negative emotions like fear, anger, shame, envy, or depression more often and more intensely than those who score low on neuroticism. Highly neurotic people have more trouble coping with stressful events, are more likely to insult or lash out at others, and are more likely to interpret ordinary situations (like minor frustrations) as hopelessly difficult. Neuroticism is closely-related to mood disorders such as anxiety and depression.
Individuals who score low in neuroticism tend to be more emotionally stable and less reactive to stress. They tend to be calm, even-tempered, and less likely to feel tense or rattled. Although they are low in negative emotion, they are not necessarily high in positive emotions, which are more commonly associated with extraversion and agreeableness. Neurotic extroverts, for example, would experience high levels of both positive and negative emotional states, a kind of "emotional roller coaster".