Study guide BBH 101H Exam 2 Exam will consist of 35 multiple choice questions and 1 essay question 1 Stress a Definition of stress stressors b History i Stress a negative emotional experience accompanied by predictable biochemical physiological cognitive and behavioral changes that are directed either toward altering the stressful event or accommodating to its effects 1 A specific response by the body to a stimulus as a fear or pain that disturbs or interferes with the normal physiological equilibrium of an organism can include biological psychological and sociocultural influences ii Stressors an activity event or other stimulus that causes stress i Claude Bernard Defined the term which is now known as homeostasis 1 Concept of homeostasis controlled stability of the internal milieu or internal environment of cells and tissues Take it apart and we can understand it cells in body look for a balance ii Walter Cannon coined terms homeostasis and fight or flight He considered both physical and psychological challenges to the organism 1 Homeostasis fight or flight Homeostasis is the body looking for balance and with any disruption we will try to get back to middle ground Fight or flight resolve conflict or fight through action Relieve pressure that stressor is putting on us iii Hans Selye experimented with rats recognized non specificity of stress response and developed concept of general adaptation syndrome GAS Endocrinologist 1 Rat experiments GAS Characteristic responses 1 adrenal glands activated and enlarged 2 thymus and spleen were shrinking 3 developed ulcers When he injected them with saline he got the same response He put them in certain conditions to create stress GAS several stages alarmed resistance and exhaustion stress was breaking the body down 2 He injected mice with extracts of various organs iv Allostasis vs homeostasis a Allostasis was developed to replace homeostasis Sterling and Eyer organisms are designed to be efficient efficiency requires trade offs efficiency requires predicting future needs prediction requires sensors to adapt to the expected range of input prediction demands that each effector adapt its output to the expected range of demand and predictive regulation depends on behavior while neutral mechanisms also adapt b Homeostasis emphasis is on steady state and optimal set points c Allostasis emphasis is on optimal operating ranges of physiological systems 2 Allostatic load Bruce McEwen fluctuation and flexibility to promote survival a Stability through change represents the cumulative multi system view of physiological toll that may be exacted on the body through attempts at adaptation c Stress physiology 3 major systems Sympathetic nervous system HPA system and immune system i SNS kicks in within seconds activated first in stress response 1 Role of norepinephrine neurons in SNS release norepinephrine noradrenaline which leads to fight or flight responses like increased heart rate respiration inhibition of digestion pupil dilation etc Fight or flight response prepares body for action Other neurons stimulate adrenal medulla to release epinephrine adrenaline and norepinephrine sympatho adreno medullary SAM system 2 Adrenal glands located just above kidneys consist of adrenal cortex and adrenal medulla a Medulla vs cortex Medulla produced epinephrine and norepinephrine Cortex produces cortisol which is a stress hormone ii HPA axis Hypothalamic pituitary adrenal axis kicks in within seconds after SNS HPA response provides energy for prolonged action 1 Know regions involved in cascade and hormones involved a Cascade CRH ACTH Cort b Hypothalamus releases corticotropin releasing hormone CRH c Anterior pituitary releases adrenocorticotrpin hormone ACTH d Adrenal Cortex releases glucocorticoid GC hormones e g cortisol e Feedback GC bind to receptors in hypothalamus and pituitary Leads to decreased CRF and ACTH production Natural mechanism to stop make sure over production doesn t happen GC bind to receptors Negative feedback can fail Negative feedback controlled device so it can cut it off and stop producing substance 2 Effects of glucocorticoids on cells breakdown fats initiate gluconeogenesis and decrease effects of insulin Overall increase the availability of glucose and other nutrients the body can use for energy Increase energy to keep up fight or flight response lasting more than a few minutes it will look like glucocorticoids d Stress control i Learned helplessness in animals humans 1 Learned helplessness experimental animals first given inescapable shock then escapable shock control animals not given inescapable shock and experimental animals try to escape less frequently in test ii Lange Roding 1976 nursing home experiment 1 Subjects were nursing home residents Personal responsibility emphasized in group 1 staff s responsibility for patients emphasized in group 2 3 weeks later group 1 happier more active more alert 18 months later 15 of group 1 had died 30 of group 2 had died Learned helplessness in humans seen after concentration camp conditions of abuse etc associated with depression elevated cortisol and elevated norepinephrine and epinephrine decreased immune function 2 Taking control from the patients control emphasized dying twice the rate Learned helplessness is learned when escapes from an aversive stimulus is impossible iii Factors that affect perception of control a Stress is increased when people feel like they are not in control of an event b Stress is decreased even when people are simply given more information about the event e g they know they will receive a shock even if they don t control it c Level of control can determine how an event is interpreted and thus if it is considered stressful 2 Information predictability predict when it will happen next e Social isolation i Extreme cases like maternal isolation a More information they are given less stressed they are They can try to 1 King Frederick s language experiment Maternal deprivation leads to elevated glucocorticoid levels in adulthood increased anxiety Took a group of babies after they were born and isolated them put them all in separate rooms He would feed and change them but wouldn t speak to them He hoped they would speak a certain language but they all died 2 Isolating monkeys from their mom Harry Harlow doll named cuddly provided food and there was another wirey one with food The monkeys chose the cloth doll They deprived the monkeys from their mom and the monkeys became