Unit 13 - Stress & Health Flashcards
biomedical vs biopsychosocial models
biomedical
- Rooted in the idea that mind and body are distinct, separable entities (mind-body dualism)
- Looks to bodily factors, rather than the mind, for explanations of health and disease
biopsychosocial
- A model of health that considers the effects of biological, psychological, and social factors on health and illness
rumination
The process of repetitively turning emotional difficulties over and over in the mind.
zebras don’t get ulcers
- their stress responses are typically acute and short-lived, triggered only during immediate survival threats, such as escaping predators. Once the threat is gone, their bodies return to a baseline state, avoiding the prolonged physiological strain that chronic stress causes.
- Humans, on the other hand, are prone to chronic stress because of our ability to ruminate—mentally replaying and worrying about past events or anticipating future problems. This sustained activation of the stress response can lead to health problems like ulcers, heart disease, and weakened immunity
Hans Selye’s understanding of stress
- Was studying a newly discovered ovarian hormone
- Rats injected with hormone developed peptic ulcers, greatly enlarged adrenal glands, shrunken immune tissues
- Exciting discovery—but problem with the research method?
- Added a control group—and observed the exact same effects!
neural and physiological pathways underlying the stress response
- two processes are called into action
- both controlled by the hypothalamus (plays role in coordinating motivated behaviours required for survival, including the fight-or-flight response)
neural alarm system and project to the hypothalamus
The brain’s neural alarm system, primarily involving the amygdala, detects threats and triggers the stress response. The amygdala sends excitatory signals to the hypothalamus, particularly the paraventricular nucleus (PVN), activating the hypothalamic-pituitary-adrenal (HPA) axis and the autonomic nervous system (ANS) to initiate the body’s response to stress.
role hypothalamus plays in the stress response
The hypothalamus coordinates the body’s stress response by activating two main systems: the autonomic nervous system (ANS) for immediate “fight or flight” responses and the hypothalamic-pituitary-adrenal (HPA) axis for the slower, hormonal response. It triggers the release of stress hormones like adrenaline and cortisol to mobilize energy and adapt to the stressor.
sympathetic nervous system
- The hypothalamus initiates sympathetic nervous system arousal
- Stimulates a part of of the adrenal glands, which secrete chemical messengers including epinephrine
- Leads to increased blood pressure, heart rate, sweating
parasympathetic nervous system
- The “brake pedal”
- Acts antagonistically to the sympathetic nervous system
- Once the emergency has passed, restores the body to a normal state, allowing resources to be devoted to life-sustaining processes such as digestion and growth
hypothalamic-pituitary-adrenal axis
- Hypothalamus initiates a chemical cascade that stimulates pituitary gland (the “master” gland)
- Hormone released by the pituitary stimulate a different part of the adrenal glands, which in turn releases hormones including cortisol
- Cortisol mobilizes sugar for fuel, increases heart rate & blood pressure, directs attention toward threat, contributes to formation of “flashbulb memories”
allostatic load
- Normally, cortisol helps the body return to its steady state following stress by inhibiting release of CRF from the hypothalamus (i.e., negative feedback)
- But sustained activation of the HPA axis can compromise its functioning—this is referred to as allostatic load(McEwen, 1998)
- Daily cortisol patterns may be altered
- While cortisol normally inhibits inflammation, prolonged stress can result in increased glucocorticoid resistance of immune cells, leading to heightened inflammation
- Chronic inflammation implicated in a large number of diseases, including depression, cancer, diabetes, cardiovascular disease
two factors, events that people find stressful
- uncontrollability
- social-evaluative threat (possibility that the self could be negatively judged by others)
trier social stress test
The Trier Social Stress Test (TSST) is a standardized procedure used to induce stress in research settings. Participants perform tasks like a public speech and mental arithmetic in front of evaluators, under conditions designed to provoke social-evaluative stress. It reliably triggers physiological stress responses, including activation of the HPA axis and cortisol release.
stress appraisal theory
- Appraisals of an event and our role in it shape our emotional experience of the event, and our physiological reactions to it
- This theory postulates that stress is what happens when the demands of the situation exceed our ability to cope
primary vs secondary appraisal
primary: A person’s perception of the demands or challenges of a given situation
secondary: A person’s perception of his or her ability to deal with the demands of a given situation
