Lecture 6: Chapter 7 – The Autonomic Nervous System and Hormones Flashcards
The autonomic nervous system is a component of the _____ _____ _____ that regulates ____ ____ ______?
The autonomic nervous system is a component of the peripheral nervous system that regulates involuntary physiological processes
The autonomic nervous system connects to organs such as the?
The heart, lungs, stomach, intestines, genitals, and smooth muscle around arteries
The autonomic nervous system consists of two chains of neurons alongside the spinal cord:
- Sympathetic system: “fight or flight” system
- Walter Cannon (1915) determined that the sympathetic nervous system prepares the body for vigorous/stressful activity - Parasympathetic system: “rest and digest” system
- Activates to relax and repair body after periods of stress
List the 6 short-term impacts from the SNS to engage in vigorous activity
- Increases blood flow to brain and muscles via vasodilation of arteries
- Relaxes and expands bronchioles (sacs in lungs) to increase oxygen intake
- Accelerates heartbeat to improve transfer of oxygen to tissues
- Dilates pupils in order for the retina to take in more light
- Also indicates sexual interest
- Increases sweating to cool down body from increased heat
- Piloerection: making the body’s hairs stand up on end
- Makes animal look larger when frightened,
evolutionary relic in humans
- Makes animal look larger when frightened,
List the 3 long-term impacts from the SNS to engage in vigorous activity
- Secretion of adrenaline, noradrenaline, and cortisol to engage body’s stress response
- Stimulates glucose production and release from liver to supply energy
- Stimulates overall cellular metabolism and breakdown of fats in body
List the 5 mechanisms of the SNS to decrease resting/relaxing behaviour
- Constricts blood flow to hands, feet, and skin via vasoconstriction of arteries
2 Inhibits peristalsis (intestine pulsing) and secretion via vasoconstriction of arteries - Inhibits salivation, leading to dry-mouth feeling
- Inhibits bladder contraction, preventing bladder emptying
- Stimulates orgasm (climaxes/ends sexual activity)
Sympathetic nerves travel ____ each other for long distances along the spinal cord, and synapses connecting to different organs are typically ____ ____
Sympathetic nerves travel alongside each other for long distances along the spinal cord, and synapses connecting to different organs are typically clustered together
Initially, researchers believed that sympathetic branch acted in “____” with each other, resulting in an ______ _____
Researchers believed that sympathetic branch acted in “sympathy” with each other, resulting in an all-or-none response
It is now understood that activation of the sympathetic branch is more _____ with different combinations of _______ and ______ _____
Now understood activation is more differentiated with different combinations of neurotransmitters and receptor subtypes
In contrast to sympathetic nerves, parasympathetic nerves ___ __ and head for different organs closer to the spinal cord. Thus?
In contrast to sympathetic nerves, parasympathetic nerves split off and head for different organs closer to the spinal cord. Thus, stimuli that activate one part of system may or may not activate other parts
List the 9 functions of the parasympathetic nervous system (rest and digest)
- Constricts pupils to conserve energy
- Stimulates flow of saliva to aid in digestion
- In cats and dogs, reflects increased parasympathetic stimulation associated with contentment - Constricts and shrinks bronchioles
- Slows heartbeat
- Stimulates peristalsis and secretion of digestive chemicals (e.g. bile) in GI tract
- Insulin secreted to facilitate the storage of energy in fatty tissues and in the liver
- Contracts bladder, allows bladder emptying
- Does not affect blood vessels directly, but less sympathetic activity will send more blood to digestive system, less to muscles/brain
- Big meals make one feel lethargic when exercising, and sleepy (less blood to brain) - Promotes body conditions favourable for sexual activity
- Increases blood vessel dilatation in genitals of males and females, facilitating sexual arousal
Explain the 1st role of the parasympathetic nervous system in emotion
A certain degree of calming is valuable for social relationships and for some positive emotions (Porges, 1997)
Explain the 2nd role of the parasympathetic nervous system in emotion
People with higher resting parasympathetic activation:
1. Tend to be better than average at regulating their emotions (Butler, Wilhelm & Gross, 2006)
2. Report more positive affect in their daily lives (Bhattacharyya et al., 2008)
Explain the 3rd role of the parasympathetic nervous system in emotion
Heart rate predicts amount of compassion people feel and show when someone else is suffering (Stellar, Cohen, Oveis & Keltner, 2015)
1. Moderately slowing your heart rate helps you focus on others and stop worrying about your own problems
2. Too much calming causes people to stop worrying about others as well
How do the sympathetic and parasympathetic systems work together?
Both work in concert to regulate bodily activity (similar to pedal and brake in a car)
Describe how the sympathetic and parasympathetic systems work together in the rabbit example
- After hearing a sudden noise, rabbit’s sympathetic NS will dilate pupils, and slightly increases sweating, and parasympathetic NS will decrease heart rate
- Helps to focus attention on outside environment
Describe how the sympathetic and parasympathetic systems work together in the human example
Humans read a list of objects and evaluated their usefulness in life-or-death situations (thinking of threats, but not yet doing anything about it)
Finding: increased attention being paid to words on the list results in increased probability of remembering words on list
Describe how the sympathetic and parasympathetic systems work together with respect to the nausea example
During nausea, sympathetic NS decreases stomach contractions and induces gagging, while parasympathetic NS stimulates intestines and salivary glands, while slowing heart rate
Describe the methods of Löw, Lang, Smith & Bradley (2008) study on how the sympathetic and parasympathetic systems work together
- Had participants play video game where they have an opportunity to win some money, and sometimes face the threat of losing it
- As gun approaches you and gets larger, you have an increased chance to lose money, unless you react quickly enough when signal appears
Describe the two findings of Löw, Lang, Smith & Bradley (2008) study on how the sympathetic and parasympathetic systems work together
- When gun is small and distant, heart rate decreases (PSN activated to increase attention)
- When gun grows larger, heart rate increases for vigorous response (SNS activated)
Define the endocrine system
Hormones in the body and the glands that produce them
Define Hormones
Chemicals produced and released by glands in one part of your body and carried by the bloodstream to cells of other areas
Insulin (hormone) is produced and released by the _____ to increase ___ ____ __ _____
Insulin is produced and released by the pancreas to increase glucose uptake in cells
Growth hormone is produced in the _____ ____ to promote ___ _______
Growth hormone is produced in the pituitary gland to promote cell reproduction
_____ is produced by the hypothalamus to promote pair-bonding
Oxytocin is produced by the hypothalamus to promote pair-bonding
Epinephrine acts similarly to the ______ ______ _____, but lasts longer because the hormone ________________________________
Epinephrine acts similarly to the sympathetic nervous system, but lasts longer because the hormone stays in the bloodstream for a while after release
_____ is slower but more longer lasting than epinephrine
Cortisol is slower but more longer lasting than epinephrine
List the 3 functions of Cortisol
- Increases blood sugar by encouraging liver to release it
- Prompts breakdown of muscles and fat to make glucose
- Increases blood pressure, partly by retaining sodium and fluids
- Increasing total amount of blood plasma pumped through system
- Increasing resistance from the arteries
Cortisol acts as a stress hormone but also involved in _____ _____
Cortisol acts as a stress hormone but also involved in biological rhythms
When does Cortisol peak and decline?
Cortisol peaks soon after waking in the morning and slowing declines throughout the afternoon/evening
What happens when there is a disruption of the biological rhythm?
- Disruption of biological rhythm associated with severe stress/mental health issues
- After going through extreme stress, people’s bodies.
may begin to give up on responding to challenging
situations
- After going through extreme stress, people’s bodies.
List the 3 demographics that show smaller cortisol responses on waking
- Women with depression
- Women living with severe economic hardship
- Adults who experienced severe and/or chronic stress as children
List the 3 demographics that show smaller than normal cortisol responses to a stressful experience later in the day
- Children who have been abused or severely bullied
- Children experiencing chronic stress
- Adults who experienced greater stress as children
What are the 3 sex hormones?
Estrogen, progesterone, and testosterone
With respect to sex hormones, women have more _____ & ______ , men have more _______, both have all 3
Women have more estrogen & progesterone, men have more testosterone, both have all 3
Higher levels of _____ have mood enhancing effects in women and drops have been linked to _____ ______
Higher levels of estrogen have both mood enhancing effects in women and drops have been linked to depressive symptoms
Young women taking birth control (giving extra estrogen) are less prone to _______.
Young women taking birth control (giving extra estrogen) are less prone to depression
Testosterone has a ________ ____ in men with minor depression, especially if ___ levels of testosterone
Testosterone has a mood-enhancing effect in men with minor depression, especially if low levels of testosterone
- No significant effect if testosterone levels are normal
Certain children react to mistreatment with a burst of _______ release, matched with an outburst of _______ behaviour. However, most studies indicate low, often nonsignificant correlation between testosterone and anger/aggression
Certain children react to mistreatment with a burst of testosterone release, matched with outburst of disruptive/violent behaviour. However, most studies indicate low, often nonsignificant correlation between testosterone and anger/aggression
In both men and women, high ratio of ______ relative to _____ correlates with increased ________ behaviour and increased _______ behaviour
In both men and women, high ratio of testosterone relative to cortisol correlates with increased aggressive behaviour and increased risk taking behaviour
People with weak _______ _______ responses feel less guilt and fear, and therefore less restraint against antisocial acts (more willing to be agressive)
People with weak sympathetic system responses feel less guilt and fear, and therefore less restraint against antisocial acts (more willing to be agressive)
Heart rate is informally measured through
Heart rate is informally measured through changes in blood pressure when holding fingers against blood vessels to count beats
Electrocardiogram (ECG) is used to detect small electrical signals when the ______ and _______ begin to contract. Thus, in order for ECG to work it places sensors on the chest on a diagonal across the heart
Electrocardiogram (ECG) is used to detect small electrical signals when the atria (upper chambers of heart) and ventricles (lower chambers of heart) begin to contract. Thus, in order for ECG to work places sensors on chest on diagonal across the heart
Describe the most characteristic portion of the ECG response
QRS complex – heart beat pattern characterized by a big spike, then a dip, and then a return to a straight line
What does QRS stand for?
Q - beginning of the contraction
R - peak of electrical activity
S - indicates start of recovery
What are the 2 ways to analyze heart signals?
- Heart rate
- Blood pressure
What is one way that heart signals are analyzed by measuring heart rate?
Measuring number of R peaks in a given period of time and scaling to a minuet
What is a second (more common) way that heart signals are analyzed by measuring heart rate?
Measure average interbeat interval: time in ms between each of the R peaks in a ECG signal, and then average numbers for period of interest
- Allows researchers to detect changes on a second by
second basis
How are heart signals analyzed by measuring blood pressure?
Reflects volume of blood in each heartbeat, and the constriction of muscles surrounding arteries
What 2 tools are used to measure blood pressure?
- Measured with sphygmomanometer wrapped around arm
- Computer-controlled monitor strapped to wrist/finger (takes readings every few seconds)
What two types of blood pressure do researchers distinguish between?
- Systolic blood pressure: pressure when heartbeat is actively pushing blood through arteries
- Diastolic blood pressure: pressure while the heart is between beats
Aside from heart rate & blood pressure, what are 4 other, less-commonly used, measures?
- Measure vasoconstriction via finger temperature (less blood = ↓ temp.)
- Measure respiration rate (i.e. breathing rate) and respiration depth (volume of each breath) by strapping an elastic belt with tension/pressure-sensitive component around one’s diaphragm
- Measure changes in pupil size using eye-tracking software while participant has head remaining still on chinrest
- Electrodermal activity (skin conductance) uses electrodes attached to skin to measure level of sweating caused by SNS
- ↑ conductance = ↑ electrical activity along skin
What are two other, more sophisticated ways to evaluate SNS & PNS activity?
- Cardiac pre-ejection period
- Respiratory sinus arrhythmia
What is the cardiac pre-ejection period?
Cardiac pre-ejection period: time elapsed between the electrical depolarization of the left ventricle and the beginning of ventricular ejection
- IOWS, in the pounding you have in each beat of your heart, the force at which your heart is squishing (pushing harder allows more oxygen to go throughout your body faster)
Describe how the cardiac pre-ejection period is measured to evaluated sympathetic activation
- Sympathetic activity makes the contraction of the heart increase in force
- Ventricles fill at Q point (beginning of the contraction)
- Measures the milliseconds between the Q point and
the expulsion of blood in the aorta - Time between the ventricles filing and the expulsion
of blood will decrease because if you’re pushing
faster there’s less time in between filing and release
- Measures the milliseconds between the Q point and
What is respiratory sinus arrhythmia?
Heart rate variability in synchrony with respiration, where the R-R interval on an ECG is shortened during inspiration and prolonged during expiration
Describe how the respiratory sinus arrhythmia is measured to evaluate parasympathetic activation
- At rest, the parasympathetic system is always slowing heart rate from its natural rhythm (e.g. from 90 bpm from the heart “pacemaker” to 70-80 bpm)
- Expansion of lungs interferes with parasympathetic NS’s ability to interfere with heart rate, leading to ↑ heart rate when inhaling
- Difference in heart rate between inhalation + exhalation (because exhalation is going to remove activity and inhalation is going to bring back PS baseline activity) = how much parasympathetic activity is impacting heart rate at rest
What are the two ways hormones can be measured?
- Blood samples
- Saliva samples
Describe the efficiency of measuring hormones with blood samples
- Most accurate way to measure hormones because they are in the bloodstream
- More intrusive
- Reliable for a larger profile of hormones than saliva
Describe the efficiency of measuring hormones with saliva samples
- Less intrusive
- Primarily used for cortisol, estrogen and testosterone
- Less reliable for other hormones
What is the first measurement challenge?
- Participants have large within-subjects variability in baseline physiological measures
- Baseline responses change over time
Ex: looking at fearful responses in one movie clip, and then looking at happy responses in another, obviously it’s gonna take a bit of time for the autonomic activity when you’re watching a fearful clip to subside before you watch the happy clip
How do researchers counteract the measurement challenge that participants have large within-subjects variability in baseline physiological measures and baseline responses change over time?
Compare change from baseline condition to target period for each emotional state to minimize noise
What is the second measurement challenge?
Highly sensitive to extraneous physiological disturbances
- E.g. movement, sneezes, talking can cause PNS and SNS activity
- Extra movement can dislodge sensors
What is the third measurement challenge?
Detection of autonomic system responses are often time-sensitive
- NS may take 1-2 seconds to react measurably to stimuli
- Changes in salivary hormones can take 15+ minutes to detect
Both James-Lange and Schachter-Singer theories require to some extent the feeling of emotion to be derived from ______ ______? If such are true then if only weak bodily sensations, then only ____ emotions possible
Bodily sensation
Weak
Describe the methods of Critchley et al. (2004)’s study investigating if bodily sensations are necessary for emotional feelings
- Asked people to report whether they thought their heart rate was increasing or decreasing
- Also report in general how sensitive their visceral
sensations were (baseline), and how intensely they
felt fear and sadness
- Also report in general how sensitive their visceral
What were the findings of Critchley et al. (2004)’s study investigating if bodily sensations are necessary for emotional feelings and what do they suggest?
- Found the people more accurate in judging heart rate reported higher sensitivity to visceral sensations, and greater intensity of unpleasant emotions
- Suggests that there’s some credence to the James-Lange and Schachter-Singer theories → at least in terms of intensity, if you are more aware of your bodily reactions you feel emotions more strongly
What are the two conditions where individuals are unable to feel their bodily sensation?
- Pure autonomic failure: a medical condition in which ANS ceases to influence the body
- Locked-in syndrome: someone loses almost all output from the brain to the muscles and the autonomic nervous system, although they continue to receive sensations
Describe the condition of pure autonomic failure
- Uncommon, onset usually at middle age, causes unknown and incurable
- Unable to stand up quickly, blood rushes out of brain to trunk, faints
- No sympathetic reflexive response to increase heart
rate and constrict (tighten) veins leading from head
to heart
- No sympathetic reflexive response to increase heart
- Physical/mental stresses have no effect on heart rate, breathing rate, sweating, or other autonomic responses
- Feel emotions less intensely than normal, appraisal part of emotion intact
What theory does the condition of pure autonomic failure lend itself to?
Schachter-Singer theory which suggests that the physiological response is the sensation that we feel when we feel subjective emotion
Describe the cause of locked-in syndrome
- Someone loses almost all output from the brain to the muscles and the autonomic nervous system, although they continue to receive sensations
- Caused by stroke or other damage to the brainstem, with key areas of the pons and medulla damaged
- Different from spinal cord injury at neck, since
parasympathetic nerves to heart/organs originate at
pons and medulla
- Different from spinal cord injury at neck, since
Describe the condition of locked-in syndrome
- Few clusters of neurons above damaged area control eye muscles
- Can control eye movements, can train patients to
communicate with eye blinks
- Can control eye movements, can train patients to
- Most patients report unemotional content (E.g. “Why do I wear such an ugly shirt?”)
- Many reports say locked-in patients are tranquil
- Do not experience fidgeting, heart palpitations,
stomach churning, or any other bodily responses
accompanying emotions
- Do not experience fidgeting, heart palpitations,
- Many reports say locked-in patients are tranquil
Even though individuals with locked-in syndrome don’t feel the emotion strongly, they’re still able to understand the ______ ______
Cognitive aspects of emotion
- Bauby (1997) report from an autobiography of a locked-in patient as referring to sadness, disappointment, frustration, and similar emotional terms
- Could be that cognitive aspects remain intact even if
intensity of emotion isn’t there
With respect to automatic specificity, basic/discrete emotions theory suggests that different emotions should be associated with ___________________________ (i.e. autonomically ______). Which theory further supports such?
- Basic/discrete emotions theory suggests that different emotions should be associated with different profiles of bodily responses (i.e. autonomically specific)
- Supported by evolutionary theory, suggesting emotions have specific adaptive (and likely physiological) functions in our body
With respect to automatic specificity, core affect theory suggests that emotions would ____ along valence and arousal, with _____ ________ between them (i.e. autonomically ______)
Core affect theory suggests that emotions would vary along valence and arousal, with strong similarities between them (i.e. not autonomically specific)
Schachter-Singer theory suggests that physiological responses determine the _____ ___ __ _______, but require ______ _____ to identify specific emotion
Schachter-Singer theory suggests that physiological responses determine the intensity of an emotion, but require cognitive appraisal to identify specific emotion
Describe the conditions of Ekman, Levenson, and Friesen’s (1983) study on autonomic nervous system specificity of emotions
- Had participants engage in 2 emotional-eliciting situations:
- Posing facial expressions for each emotion via
muscle-by-muscle instructions - Reliving strong emotional memories
- Posing facial expressions for each emotion via
- Used professional actors and researchers studying facial movements as participants to ensure accuracy
- Only participants reporting moderately strong experience of the target emotion were used
Describe the measurement of Ekman, Levenson, and Friesen’s (1983) study on autonomic nervous system specificity of emotions
- Measured heart rate, finger temperature, skin conductance, muscle tension
- Looked at baseline-to-trial differences for each of the emotions
Describe the 3 findings of Ekman, Levenson, and Friesen’s (1983) study on autonomic nervous system specificity of emotions
- Heart rate increased substantially for only anger, fear and sadness
- Finger temperature increased most during anger, and somewhat during happiness and surprise
- Skin conductance increased most for anger, fear, sadness, and disgust
**But these results were not always consistent
Describe the first consistent finding across all studies from Cacioppo and colleagues (2000) metaanalysis to consolidate studies involving autonomic specificity
- Happiness generally produces less arousal than anger, fear, sadness, or disgust (positive affect → less arousal)
Describe the second consistent finding across all studies from Cacioppo and colleagues (2000) metaanalysis to consolidate studies involving autonomic specificity
- Heart rate accelerates more during anger, fear, and sadness than disgust
- Reason why disgust didn’t have higher heart rate:
nausea produces both sympathetic and
parasympathetic activation, potentially cancelling out
effect on heart rate
- Reason why disgust didn’t have higher heart rate:
Describe the third consistent finding across all studies from Cacioppo and colleagues (2000) metaanalysis to consolidate studies involving autonomic specificity
- Compared to fear, anger produces higher blood pressure, smaller increases in heart rate and stroke volume, and greater finger pulse volume and temperature
List and describe the first reason why Levenson (2014) argues that the autonomic specificity research is inadequate
- Should expect distinctive autonomic responses for strong emotions
- Because of ethical constraints, most investigators
used weak manipulations
- E.g. Remember a time when you felt a certain
emotion
- E.g. Look at a photo or movie clip to elicit an
emotion
- Thus, could be that when you elicit more stronger emotions that autonomic responses are much more selective, but if everything is weak, then everything feels the same in terms of physiology
- Because of ethical constraints, most investigators
List and describe the second reason why Levenson (2014) argues that the autonomic specificity research is inadequate
- Many researchers examine only a limited range of physiological responses
- Often heart rate and skin conductance, since they
are easiest to measure - Not looking at visceral responses in stomach and
intestines - Rarely look at cardiac pre-ejection period and
respiratory sinus arrhythmia
- Often heart rate and skin conductance, since they
List and describe the third reason why Levenson (2014) argues that the autonomic specificity research is inadequate
- Most emotions are only intense for a few seconds
- Important to measure responses in real time, not
just averaged over certain periods
- Important to measure responses in real time, not
Levenson, Ekman, Heider and Friesen (1992) found ___ specific and universal _______ aspects to emotion between Americans and Minangkabau in Indonesia
Levenson, Ekman, Heider and Friesen (1992) found cultural specific and universal physiological aspects to emotion between Americans and Minangkabau in Indonesia
Describe the methods of Jeanne Tsai and colleagues (2002) study
- Had American college students as participants from European or Hmong descent
- Hmong participants had to be first or second
generation immigrants, and fluent in Hmong and
English
- Hmong participants had to be first or second
- Asked participants to relive experience feeling happiness, pride, love, anger, disgust, or sadness
Describe the finding, with respect to skin conductance, from Jeanne Tsai and colleagues’ (2002) study and what it suggests regarding universality/culture
Skin conductance increases slightly for all 6 emotions and equally for both groups → there is some universality in emotion in how we respond independent of culture
Describe the methods of Shiota and colleagues’ (2011) study on physiological aspects of positive emotions
- Presented photos to elicit 5 different positive emotions to examine physiological differences
- Enthusiasm: eagerness for food or other rewards
- Attachment: love and trust for a parent, friend of
loving partner - Nurturance: tendency to care for the young or other
helpless beings - Amusement: play and humour
- Awe: response to novel, amazing sights or
experiences
Describe the first significant finding from Shiota and colleagues’ (2011) study on physiological aspects of positive emotions
- Enthusiasm, attachment, nurturance both show decreases in cardiac interbeat interval (faster heart rate → increased SNS activity) and respiratory sinus arrhythmia (decreased PS activity)
- Only enthusiasm also showed increased skin
conductance and mean arterial pressure (more SNS
activity)
- Only enthusiasm also showed increased skin
Describe the second significant finding from Shiota and colleagues’ (2011) study on physiological aspects of positive emotions
- Amusement shows no difference from neutral photos across all measures
- Meaning that w/out a physiological response or
changes in physiology you can still cognitively feel a
certain emotion)
- Meaning that w/out a physiological response or
Describe the third significant finding from Shiota and colleagues’ (2011) study on physiological aspects of positive emotions
- Awe showed increase in cardiac pre-ejection period (decrease in SNS activity), decrease in respiratory sinus arrhythmia (decrease in PNS activity)
Moral elevation (positive emotion) is the reaction to _______________
Moral elevation is the reaction to heroic, altruistic acts by other people
What are the physiological effects of moral elevation (positive emotion)?
- Produces increased heart rate (↑ sym. activity) but also increased respiratory sinus arrhythmia (↑ parasym. activity) (Piper, Saslow, & Saturn, 2015)
- Thus, you have more feedback from PNS and increased SNS activity because it motivates you in some way but also relaxes you because you’re seeing someone else do something good
Undoing effect of positive emotion is when…?
Undoing effect of positive emotion is when positive emotions help recover after intense negative emotion physiologically as well as emotionally
What are the physiological effects of the undoing effect of positive emotion?
E.g: After watching scary clip that raises heart rate, blood pressure and sweating, positive clip helps individuals return to baseline physiological changes (Fredrickson, Mancuso, Branigan, & Tugade, 2000)
What is a specific example of how stress can affect health?
Death of spouse leaves survivor more vulnerable to illnesses
- E.g. dental problems, stroke, heart attacks, depression
- Increased chance of survivor dying in the next few
months
What is the first reason as to why the death of spouse leaves the survivor more vulnerable to illnesses?
- Problems that plagued and killed spouse exist with survivor (e.g. same accident, same infection)
What is the second reason as to why the death of spouse leaves the survivor more vulnerable to illnesses?
- Could be due to disruption of daily lifestyle while grieving
- E.g. not eating/sleeping properly
What is the third reason as to why the death of spouse leaves the survivor more vulnerable to illnesses?
- Physiological disturbances of hypothalamuspituitary-adrenal (HPA) axis → stress itself from the event can have detrimental effects on your health
Specifically describe how physiological disturbances of hypothalamuspituitary-adrenal (HPA) axis → stress itself from the event can have detrimental effects on health
- Hypothalamus releases corticotrophin releasing hormone (CRH) to anterior pituitary gland
- Triggers anterior pituitary gland to release adrenocorticotropic hormone to activate adrenal cortex
- Adrenal cortex triggers release of epinephrine and cortisol into the blood stream to trigger stress response
What did Hans Selye notice regarding ill patients?
Hans Selye noticed that almost all patients that went ill had similar symptoms
- E.g. Fever, lack of appetite, lethargic, sleepy, low sex
drive, & increased activity in immune system
What happened in Hans Selye’s initial research with lab rats that he would inject either with a carcinogenic substance or saline?
- Was not good at giving injections, missed injection spot, got bitten, dropped rat, chased it around → inadvertently created a stressful environment for the rates
- Found both control and exp. groups had high rate of cancer
- More technically skilled research assistant’s rats had
less chance to get cancer
- More technically skilled research assistant’s rats had
Based on his initial findings, Hans Selye wanted to investigate a bit more to see if the stressful events were actually triggering the higher incidence of cancer in the rats. What did he find with respect to physiological activity?
Found that prolonged heat/cold, pain, poisons, enforced activity (e.g. confinement to motorized running wheel), frightening stimuli (e.g. a cat, aggressive rat):
1. Increased heart and breathing rate
2. Enlarged adrenal glands
3. Weakened immune system
4. Increased the risk of stomach ulcers
The general processes your body goes through when you are exposed to any kind of demand, positive or negative (general definition to any changes that occur in your body) is known as ________?
Selye’s General Adaptation Syndrome/Stress
What are the three stages of Selye’s General Adaptation Syndrome/Stress?
- Alarm
- Resistance
- Exhaustion
Breakdown the first stage of Selye’s General Adaptation Syndrome/Stress
- Alarm: Brief period of high arousal of the SNS
- Adrenal glands secrete epinephrine and cortisol
- Increased availability of glucose in bloodstream for cell uptake
- Increases breakdown of carbohydrates, fats, and proteins
- Stimulates attention, memory, and immune system activity (natural killer cells, leukocytes, and cytokines)- Some cytokines promote inflammation to heal
wounds, and trigger fever response to fight
infection
- Some cytokines promote inflammation to heal
Breakdown the second stage of Selye’s General Adaptation Syndrome/Stress
- Resistance: the body maintains prolonged but moderate arousal
- Although SNS activity declines, adrenal cortex
continues to release cortisol → still have resources to
fight off some potential threat (either physical or
psychological)
- Although SNS activity declines, adrenal cortex
Breakdown the third stage of Selye’s General Adaptation Syndrome/Stress
- Exhaustion: weakness, fatigue sleepiness, loss of appetite and motivation
- Prolonged fight against potential threats weakens
ability to function- Less energy available for protein synthesis if
resources depleted
- Less energy available for protein synthesis if
- Prolonged fight against potential threats weakens
With respect to stress and its health consequences, it has been found that ________ _______ increases risk of psychological depression, diabetes, and other disorders
Prolonged inflammation
With respect to stress and its health consequences, it has been found that increased metabolic activity, overstimulation, and increased exposure to toxins has resulted in…?
Hippocampal cells damaged by cortisol
In some brain areas, cortisol causes shrinkage of dendrites and loss of synapses, but growth in other regions. What does this impair and what does it strengthen?
- Impairs function in prefrontal cortex, while strengthening activity in the amygdala and striatum (part of basal ganglia)
- Impairs attention, planning, working memory
- Strengthening fear processing, and learned habits,
leading to more impulsive behaviour
Describe the Social Readjustment Rating Scale (measure of stress)
Checklist to measure people’s stress by how many life-change items they checked
- Includes undesirable events
- E.g. death of loved one, divorce, or losing one’s job
- Includes desirable outcomes
- E.g. marriage, birth of child, taking a vacation
Describe the Social Readjustment Rating Scale’s methods
- Asked 300+ people to rate the stressfulness of various events relative to each other
- Used average values to develop scale of relative
weights
- Used average values to develop scale of relative
Describe the Social Readjustment Rating Scale’s results
- Median score of US adults: 145
- Mean score of US adults: 278
- Positively skewed distribution (more to the left)
- Might be a product of age, ps could have been
older → higher accumulation of stressful events - ¼ of people report zero
- More than 5% report scores above 1000
- Positively skewed distribution (more to the left)
Describe the first problem with the Social Readjustment Scale
- Gives disproportionate points for relatively minor events
- E.g. Graduating college (26), get some unexpected
money (33), move to a new address (35), and start a
new job (43) = 137 points - Getting a divorce = only 71 points
- Death of spouse = only 81 points
- E.g. Graduating college (26), get some unexpected
Describe the second problem with the Social Readjustment Scale
- Many items are ambiguous
- E.g. major disagreement with boss/coworker item- Being laid off more impactful for older adult with
dependents vs. young adult
- Being laid off more impactful for older adult with
Describe the third problem with the Social Readjustment Scale
- Greatest threats to physical/mental health come from feeling of personal rejection
- Thus, it’s not really accurate to say that positive
outcomes produce the same or similar magnitudes
of stress that a negative one can
- Thus, it’s not really accurate to say that positive
In contrast to Selye’s definition, Bruce McEwan defined stress as “an event or events that are interpreted as _______ to an individual, and which elicits _____ and _____response”
“an event or events that are interpreted as threatening to an individual, and which elicits physiological and behavioural response”
What is the first component of Bruce McEwan’s definition of stress that differs from Selye’s definition?
- Limits events to threatening ones, instead of all kinds of change
What is the second component of Bruce McEwan’s definition of stress that differs from Selye’s definition?
- Defined in terms of the event that caused it, rather than the body’s reaction to change in one’s life
What is the third component of Bruce McEwan’s definition of stress that differs from Selye’s definition?
- Depends on how the individual interprets the event, not just the event itself
- E.g. Expecting a promotion at work and not
receiving it would not be stressful under Selye’s
definition, but would be under McEwan’s
- E.g. Expecting a promotion at work and not
