Sapolsky Terms Flashcards
stress response
- Stress response is the reaction of the human body to stress &
- It works to reestablish homeostasis
homeostasis
- idea that the body has a ideal settings (temperature, acidity, oxygen) that it needs to function
- stressors are what knocks the human body out of homeostasis
- the human body reaches homeostasis through a local regulatory system
allostasis
- a system that works to maintain homeostasis in the body but recognizes that there are different ways in which one can regulate a certain set point
- allostasis coordinates body-wide changes (including changes in behavior
sympathetic and parasympathetic nervous system
- both are component of the autonomic nervous system that control involuntary and automatic reactions and plays a key role in the reactions towards stress
- the sympathetic and the parasympathetic nervous system work in opposites to arouse and calm the body down when necessary
control of glucocorticoid secretion p 31.
• Glucocorticoids are steroid hormones that act similarly to epinephrine
o Epinephrine acts immediately, glucocorticoids prolong this activity
• when a stressor is perceived, the hypothalamus secretes releasing hormones to the pituitary gland and places
o example: CRH corticotrophin releasing hormone
• the anterior pituitary release ACTH
• ACTH enters the blood stream and triggers the release of glucocorticoids by the adrenal gland
fight or flight/tend and defend
- psychologist Walter Cannon developed the idea of the fight or flight syndrome to describe the adaptive components stress response stimulate by glucocorticoids
- psychology Shelley Taylor more recently proposed the idea that the fight-or-flight method is a manifestation of stress in males and has been overemphasized because of psychology’s tendency to focus on studying males
- Taylor argues that in females, the hormone oxytocin (secreted during stressful situations in females) is more related to the tend and befriend system
- The tend and befriend system is the idea that a female under stress will look to take care of her young and seek social affiliation
examples of positively valenced experience possibly being stressful
• overwhelming pleasant experiences can activate the sympathetic nervous system in ways similar to what stress does (sex, extreme happiness)
voodoo death
- phenomenon (present in non-westernized cultures) in which someone commits an offense, and a shaman or someone believed to have magical or spiritual capacities is called upon to curse the offender and the offender later drops dead
- psychologists refer to this as psychophysiological death attribute to explicable causes
- example: shaman hexes an already ill person or poisons them; or the community think that the persons condemned upon being cursed and does not waste resources tending to them
- Cannon proposed that it was due to the over activity of the sympathetic nervous system: person becomes so nervous that their cardiovascular system constricts to the point of rupture
- Ritcher: proposed that it was over activity of the parasympathetic nervous system
- Significance: voodoo death illustrates the impact one’s mental state has on their body
Type A personality and stress related illness
• risk of cardiovascular disease is increased by hostility (type A personality) and by clinical depression
relation of stress to adult onset diabetes
• adult onset diabetes is caused by the failure of cells to respond to insulin
o insulin encourages fat cells to store more fat, fat cells are not responsive to insulin and less glucose is taken up by these cells and floats in the circulatory system
o overstuffed fat cells release hormones encouraging other fat cells and muscle to become insulin resistant
o pancreas tries to pump out more insulin, eventually damaging itself
• Stress
o The stress response causes glucose and fatty acids to go into the blood stream, increasing the possibility for clots
o Stress response requires that fat cells become less responsive to insulin (long term storages processes are stopped during the stress response)
o Chronic stress makes these effects long term
Hyper and hypophagic
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Metabolic syndrome
• A terminology used for one someone suffers from one or more of all the negative side effects of long term stress-
• These side-effects include, but are not limited to
o Elevated glucose levels
o Elevated blood pressure
o Insulin resistance
o Too much LDL cholesterol/ to little HDL
o Too much fat or cholesterol in the blood
• If one has a subset of these, then they are likely to obtain others or predict illnesses such as hypertension, high cholesterol, insulin resistance, obesity etc
effects of prenatal stress
• Metabolic imprinting/ programming
o A woman who is malnourished while pregnant will be “conditioning” the fetus to survive with little to no nourishment and obtains a thrift metabolism (storing any type of nourishment that it can receive)
o As the fetus becomes an adult and is more at risk for hypertension, obesity, type II diabetes, and cardiovascular disease
o If you are a first trimester fetus during a period of malnourishment, you are more likely to development heart disease, obesity, and poor cholesterol
o If you are a second/ third trimester fetus, you are at a greater risk for diabetes
Dutch hunger winter study
- at the end of War World II, Nazis cut off food transport to the Dutch & the Dutch subsequently starved
- the fetuses of malnourished pregnant women develop thrifty metabolisms and later we have a generation of people (these fetuses that have now become adults) who have increased risk to Metabolic syndrome (after gaining access to a healthy diet)
effect of prenatal stress on adult glucocorticoids
- prenatally stressed rats grow into adults with an increased level of glucocorticoids b/c glucocorticoids are abundant in the fetal circulation that the fetus obtains from the mother
- result of decreased number receptors for glucocorticoids, less effective in mediating glucocorticoid secretion
- contributes to lifelong risk of Metabolic syndrome
stress dwarfism
• result of long term stress experienced by young children
• the child can recover if the stressor is removed before puberty but some shortness and stunted emotional and intellectual growth may result in childhood
• biologically is the result low levels of growth hormone; stimulatory/ inhibitory hormones for growth hormone is released by the pituitary gland
o during stress, the inhibitory hormones are released
o stress dwarfism children have elevated glucocorticoid levels, which also contributes to stunted hormone growth release and slow responsiveness to growth hormone
o stress also reduces gastrointestinal activity & stunted absorption of nutrients in the intestines
effects of touching premature babies
- premature babies who were touched for 15 minute periods, three times a day grew 50% faster than premature infants who were in near-sterile conditions with no bodily contact
- this carried over long-term until after the infants were discharged
Harlow’s monkey study
• Experiments helped show how infants become attached to their mothers
• Behaviorists thought that this was because mothers supply food (positive reinforcements)
• Harlow’s presented two rhesus monkeys with two surrogate mothers
o One with milk but a mesh and wire torso
o surrogate mother with a torso wrapped & terry cloth
o baby monkey choose the terry cloth mother
• indicate that infants are attached to their mother for comfort
how does stress affect the immune system?
- Selye discovered that immune tissues (thymus gland) atrophied in rats that experienced regular stress
- Inhibits the formation of new lymphocytes
- Inhibits the release of lymphocytes into the circulatory system
- Decreases the life span of preexisting lymphocytes
- Inhibit the manufacturing of new antibodies in reaction to a new pathogen
- Disrupt communication among lymphocytes
impact of social support and social isolation
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Wall-Melzack model of pain
- a pain fiber send a message to the spine; these messages can be fast or slow
- a neuron in the spine send a message to message to the brain that something painful has happened
- sudden pain stimulates a neuron and an interneuron while slow pain stimulates
allodynia
• The feeling of pain in response to a normal stimulus
o can be the result of severed nerve endings that are repaired such that they tangle together and the neurons become hypersensitive
Stress induced analgesia
• People who are highly aroused/ in high stress situations (such as battle) tend not to notice their injuries or perceive them as less painful than those with similar injuries but under less stress
endorphins
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pain and chronic stress
long-term pain produces a long term effect of opioids being secreted. Sometimes, the opioids are depleted
the depletion of opioids means that stressed induced analgesia is a short term fix
stress and enurisis
in many children and some adults stress causes loss of control of the bladder
potentially to alleviate the dead weight in what could be a life or death situtation
cardiovascular disease, how it happens; symptoms associated with stress related cardiovascular disease; CRP; and social group hierarchy effects; occurrences of ischemic crises
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stress and dieting; hyperphagia and hypophagia; CRH - ACTH cascade, glucocorticoids and appetite. glucocorticoids and recovery from stress. contrast acute or intermittent and longer lasting stress. Apple versus pear..why are they differentially diagnostic of stress?
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